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Home My WebLink About158-89 RESOLUTION NO. 158 - 89 A RESOLUTION OF THE TOWN COUNCIL OF THE TOWN OF DANVILLE Approving Proposed 1989 Revision to the County Solid Waste Management Plan (14 C.C.R., section 17147) WHEREAS, as required by the Nejedly-Z'Berg-Dills Solid Waste Management and Resource Recovery Act of 1972 (the "Act") and related regulations, the County of Contra Costa has prepared the final draft of the proposed 1989 Revision to the County Solid Waste Management Plan (the CoSWMP Revision"); and WHEREAS, in conjunction with the preparation of the proposed 1989 CoSWMP Revision, the County prepared a Draft Environmental Impact Report, held a hearing on the Draft EIR before the Zoning Administrator in accordance with the County's CEQA Guidelines, and prepared a Final Environmental Impact Report comprising the Draft EIR and a Response Document containing a list of persons, organizations, and public agencies commenting on the Draft EIR, and responses to significant environmental points raised in the review and consultation process; and WHEREAS, on August 15, 1989, the County Board of Supervisors, after due notice, held a public hearing at which the Board heard comments from County staff and the public on the final draft of the proposed 1989 CoSWMP Revision. After the hearing was closed, the Board of Supervisors certified the Final Environmental Impact Report as adequate, submitted the proposed 1989 CoSWMP Revision to the cities of the County for approval, and declared its intent to approve it, upon its approval by a majority of the cities containing a majority of the population in the incorporated area of the County; and WHEREAS, after due notice, on October 2, 1989, the Town Council held a public hearing at which the Council heard comments from the public on the final draft of the proposed 1989 CoSWMP Revision. NOW. THEREFORE. BE IT RESOLVED that having considered the environmental effects of the proposed 1989 CoSWMP Revision as shown in the Final Environmental Impact Report, the Town of Danville hereby approves the proposed 1989 CoSWMP Revision; and -2- In connection with its approval of the proposed 1989 CoSWMP Revision, the Council hereby makes findings for the significant environmental effects identified in the Final Environmental Report prepared by the County, as set forth in the "Environmental Impact Report Findings and Monitoring Program" attached hereto as Exhibit A and incorporated herein by this reference. PASSED, APPROVED AND ADOPTED by the Town Council of Danville at a regular meeting on the 2nd day of October, 1989, by the following vote: AYES: GREENBERG, JAGGER, LANE, RITCHEY, SCHLENDORF NOES: NONE Mayor ATTEST: APPROVED AS TO FORM: EXHIBIT A ENVIRONMENTAL FINDINGS AND MONITORING PROGRAM PROCEDURES The Town Council of Danville, Contra Costa County, California, finds that: The California Environmental Quality Act (CEQA), as amended, together with the State CEQA Guidelines, requires the preparation of an Environmental Impact Report (EIR) for certain public and private sector projects requiring discretionary actions by California's governments. The discretionary approval powers over the proposed CEQA project known as the 1989 Revision to the Contra Costa County Solid Waste Management Plan ("CoSWMP") resides with the County, a majority of the 18 cities within the County containing a majority of the in- corporated population, and the California Waste Management Board. The County, as the Lead Agency, determined that an EIR was required for this project and issued a Notice of Preparation on January 25, 1989, to the State Clearinghouse and to various public agencies (including all the cities in the County), organizations and individuals. As part of the environmental review process, the County held a public scoping session on February 15, 1989. The County determined that the EIR should address the general environmental impacts associated with implementation of the CoSWMP's policies and programs on solid waste management. These impacts include, but are not limited to, those associated with solid waste facilities, solid waste collection/transport, and potential interim disposal measures such as in-County waste diversion and out-of-County waste export. In addition,~ the EIR is to serve as the environmental documentation for amending the Contra Costa County General Plan to include any or all of the five landfill sites included in the CoSWMP.- The need to include these General Plan Amendments as part of the EIR was created by regulations implementing the California Solid Waste Planning Law requiring that "Reserved" waste disposal sites shown in the CoSWMPs also be shown in the General Plans of the counties or cities having jurisdiction. The County determined that the California Environmental Quality Act documentation for the CoSWMP/General Plan Amendments and the individual solid waste development projects which could result from the CoSWMP/General Plan Amendments be prepared in stages· The first tier is a Program EIR, the subject of these findings, on the CoSWMP and General Plan Amendments, which analyzes the possible environmental consequences of implementing the solid possible environmental consequences of implementing the solid waste management policies in the CoSWMP and adopting General Plan Amendments. The second tier of the process will be the environmental review of individual projects for the specific facilities proposed and designed to fulfill the goals and policies of the CoSWMP; this level of review generally will be accomplished through site-specific Project EIR's. Together, the two tiers are intended to carry out the California Environmental Quality Act and implement the State's and the County's CEQA Guidelines. On May 15, 1989, a Draft EIR for the CoSWMP/General Plan Amendments was published by the County and distributed to the State Clearinghouse and the 18 cities in the County. The County Zoning Administrator held a public hearing on this draft document in the City of Pittsburg on June 20, 1989. The public review period ended on June 30, 1989. On August 2, 1989, the Final EIR for the CoSWMP/General Plan Amendments was published, consisting of the Draft EIR and the Response to Comments document. On August 7, 1989, the Contra Costa County Zoning Administrator found that the Final EIR for the CoSWMP/General Plan Amendments was prepared and processed in accordance with the California Environmental Quality Act, and that the EIR is adequate in its coverage of environmental impacts, mitigation measures, alternatives, and other environmental effects that could result from the adoption of the CoSWMP and the five General Plan Amendments. Further, the Zoning Administrator transmitted the Final EIR to the Board of Supervisors with the recommendation that it be certified. On August 15, 1989, the Board of Supervisors certified that the Final Environmental Impact Report for the proposed 1989 CoSWMP Revision had been completed in compliance with the California Environmental Quality Act and that it had been presented to the Board and the Board had considered the information contained in it. The Town, as a responsible agency, has determined that a written finding, accompanied by an explanation of the rationale for the finding, be prepared for each potentially significant impact identified in the Final EIR. In addition, as required by recent State legislation (Pub. Resources Code, § 21081.6 [AB 3180]), every public agency making such findings must adopt a reporting or monitoring program for the changes to the project which it has adopted or made a condition of project approval in order to mitigate or avoid significant impacts to the environment. The Town Council finds that the following impacts, which could result from implementation of the proposed 1989 CoSWMP Revision's policies and programs, are potentially significant from an environmental standpoint. As to each of the following impacts, the Town Council makes the following finding: Finding: Changes or alterations to the project are within the responsibility and jurisdiction of the County and not the Town. Such changes can and should be adopted by the County. The Town Council finds further that none of the described environmental effects result either directly or indirectly from the Town Council's approval of this project, and that therefore the Townhas no responsibility for mitigating or avoiding the effects described in the Final EIR. Evidence: The proposed 1989 CoSWMP Revision has been prepared by the County, and general plan amendments to make the landfill sites in the CoSWMP consistent with the County's General Plan, and other entitlements, such as rezonings, land use permits, cancellations of Williamson Act contracts, and Solid Waste Facilities Permits, must be prepared, processed, and adopted by the County. ExDlanation: The potential impacts identified in the proposed 1989 CoSWMP Revision can be mitigated only by the mitigation measures set forth below and adopted by the County Board of Supervisors. The Town has no jurisdiction over those mitigation measures. The Town understands that the County is currently considering general plan amendments making one or more of the identified landfill sites consistent with the County's General Plan, is considering adoption of the following mitigation measures, and is processing applications for landfill siting entitlements. The County should adopt such mitigation measures as changes to the current project. In the event that a solid waste facility comes under the jurisdiction of the Town, the City Council hereby directs the Town.Manager to address the following impacts, and evaluate the following mitigation measures in the subsequent tiers of Environmental Impact Reports and other environmental documents implementing the California Environmental Quality Act that will emanate from the adoption of the 1989 County Solid Waste Management Plan and from the establishment of such facility. If the project-level tier of environmental documents also finds that the impacts are significant and that the particular mitigation measures are necessary to achieve substantial mitigation, the · own Council declaKes its intent to adopt them as parts of the applicable projects or program approvals if the measures are subject to the control of the City. Further, the TOwn Council directs that the monitoring program -- primarily an annual report on the implementation of the mitigation measures -- be carried out by the Town Manager, as to any activity carrying out the proposed CoSWMP that is under the Town's jurisdiction. The Town Council directs that all other Town~ departments and agencies involved in solid waste management assist with the preparation of the monitoring reports. POTENTIALLY SIGNIFICANT IMPACTS WHICH ARE CONSIDERED MITIGABLE TO INSIGNIFICANCE I. PLANNING AND LAND USE 1. Impact: The existing County land use designation for all five landfill sites is inconsistent with a landfill use. a. Mitiaation: The identified landfill sites in the CoSWMP require general plan amendments in order to make them consistent with a landfill use. b. SuDDortinQ Rationale: California Planning law requires waste disposal sites to be shown in the General Plans of counties or cities having jurisdiction. The County, however, has not pre-designated future landfill sites in its General Plan. By intent, new sites are to be added, when necessary, through the amendment process. All five of the sites identified for landfills in the CoSWMP are within the unincorporated area of the County and, therefore, are subject to the County General Plan. The General Plan Amendments would address the Refuse Disposal Plan, and the Land Use and Open Space/Conservation Elements of this General Plan. These amendments would enable findings of General Plan consistency to be made for the identified sites when the County Planning Commission and Board of Supervisors consider Land Use Permits and other planning entitlements. The County has initiated General Plan Amendments for the five landfill sites included in the CoSWMP. The amendments are scheduled to be considered by the Board of Supervisors in September 1989. Monitorinq Proqram: The status of this requirement shall be included in an annual monitoring report on solid waste planning submitted to the County Board of Supervisors (Board). 4 2. ImDact: In the unincorporated area of the County, applicants for transfer stations and resource recovery facilities within land use designations other than Heavy Industrial or Agricultural, with appropriate zoning, would put such applications in conflict with both the current and the Preliminary Draft County General Plans. a. Mitiqation: Any solid waste facility proposed on a site which is inconsistent with the applicable jurisdiction's general plan must apply for and receive a general plan amendment in order to facilitate its siting. b. SuDDortinq Rationale: None of the land use designations outlined in either the County's current or the Preliminary Draft County General Plan specifically identify solid waste transfer or major resource recovery facilities as allowable uses, but Chapter 418-4 of the County Ordinance Code allows waste disposal facilities to be considered in the Heavy Industrial zone, and in agricultural areas zoned A-2 or A-3 under the Land Use Permit procedures. A General Plan Amendment would be required to allow a solid waste facility to be considered at a particular location in a General Plan Land Use Element category which allows H-I, A-2, or A-3 zoning. The Community Development Department shall require a proponent of a solid waste facility site which is inconsistent with the General Plan to apply for and receive general plan amendment before accepting an application for a Land Use Permit. c. MonitorinQ Proqram: The status of this requirement shall be reported by the Community Development Department in its annual monitoring report to the Board. 3. Impact: Landfill operations at any of the five proposed landfill sites would remove agricultural usage (currently grazing) from at least parts of these sites for the life of the landfill. a. Mitiqation: Mitigation measures would include enhancing the grazing capabilities on the remainder of the landfill site or on another site. b. SuDDortinq Rationale: If landfill operations on the sites identified in the CoSWMP were to occur, existing agricultural (grazing) use currently on the active portion of the landfill site(s) would be displaced. The project-specific environmental review would include on-site and/or off-site mitigation measures, such as enhancement of the site~' grazing capabilities. In 5 some cases, it may be preferable to substitute other uses, such as recreation or habitat, for grazing. The County Community Development Department shall address the potential loss of agricultural values in site- specific EIRs, and, where found to be appropriate, shall ensure that the agricultural values' mitigation measures identified in EIRs to reduce this impact to a less than significant level are implemented by making them Land Use Permit Conditions of Approval. c. Monitorinq Proqram: The status of this siting criterion as it applies to proposed and sited landfills shall be reported to the Board annually. 4. ImDact: Surrounding residential, commercial and recreational uses could be adversely affected by the siting of landfills. a. MitiQation: The implementation of the mitigation measures identified elsewhere in the Environmental Impact Report concerned with traffic reduction and control, prevention of air and water pollution, and visual mitigation, will help reduce these impacts in many cases to insignificance. b. SuDDortinQ Rationale: Specific environmental issues that would affect surrounding land uses can be found in the Program EIR's sections on Air Quality, Visual Quality, Noise and Transportation. Impacts identified in these sections can result in significant land use impacts to nearby land uses. The mitigation measures identified in these sections would be addressed in project-specific EIRs. Most of the mitigation measures are capable of being implemented by the County, and are appropriate for inclusion in Land Use Permit Conditions of Approval or Solid Waste Facilities Permits. c. Monitorin~ Proqram: The status of this siting criterion shall be included in the annual monitoring report to the Board, and are subject to control by the County. 5. ImDact: The operations for portions of the Bay Pointe, Kirker Pass, and Keller Canyon Landfill sites could be inconsistent with the Concord Naval Weapons Station Explosive Safety Easement requirements if filling activity were to occur within the easement area. a. Mitiqation: Due to the Naval Weapons Station easement restrictions, filling operations would be limited to areas which are not affected by the safety easement; alternately, the terms of the easement would have to be 6 changed by the U.S. Navy or relinquished by sale of the easement area. b. SuDDortinq Rationale: The Department of the Navy restricts activity within the designated safety easement area adjacent to the Concord Naval Weapons Station. The Keller Canyon Landfill site, though partially included within the easement area, probably will be consistent with this requirement because the landfill's footprint (area of fill operations) is outside of the easement boundary. Similarly, the Kirker Pass Waste Management Landfill would avoid the easement. The Bay Pointe Landfill proposed footprint, however, is located within the easement and is subject to this requirement. It is not expected that the U.S. Navy will consider changing the terms of the easement or selling it back to a landowner in the next several years. c. MonitorinQ Proqram: The County Community Development Department shall ensure that the Department of the Navy's restriction on landfill operations in the safety easement be observed by making it a Condition of Approval for any proposed landfill at these sites. The County Community Development Department shall report annually to the Board on this Naval Department restriction and its enforcement. 6. ImDact: There could be significant land use impacts resulting from increased traffic and noise, and decreased safety and air quality along the access routes to both the existing Contra Costa landfills and the out-of-County sites if they are used for the diversion of County solid waste. a. Mitiqation: Use of the existing Acme transfer station (or other transfer station that may be placed into operation during the diversion period) by collection trucks and self-haulers would reduce truck traffic going to landfill sites. The scheduling of truck traffic to avoid peak periods would also help reduce to less-than-significant levels the traffic, noise, safety and air quality impacts due to truck traffic. In addition, specific environmental review for waste diversion projects would identify additional and/or more specific mitigation measures for these impacts. b. SuDDortinq Rationale: If the County chooses to temporarily divert part or all of its solid waste to County landfills and/or out-of-County landfills, the land use impacts along access routes could be significant. By requiring collection trucks and self- haulera to use the Acme transfer star±on, or other 7 available transfer station, traffic will be substantially reduced along access routes to the landfill sites. This vehicle routing plus the scheduling 0f transfer truck movement to off-peak hour times will reduce impacts to existing traffic volumes, noise levels, and air pollution and safety hazards. Further measures to reduce these impacts may be found in other sections of the Environmental Impact Report (Air Quality, Noise Transportation, and Socio- economics) as well as in project-specific EIRs. The County Community Development Department would provide for the implementation of the identified mitigation measures by making them Conditions of Approval for any County-issued permit for a diversion project. c. Monitorinq Proqram: It is noted that Alameda and Solano counties are proposing versions of these mitigation measures in their import conditions of approval. An annual monitoring report on the status of implemented measures to mitigate these impacts shall be submitted to the Board by the County Community Development Department. 7. Impact: Depending on the final sites proposed for the West, East and South County transfer stations, conflicts with existing and planned land uses in the vicinities of the sites could occur. a. Mitiqation: The potential for land use impacts due to siting a transfer station must be analyzed during project-specific environmental review. The identification of appropriate mitigation measures would be detailed at this time as well. These could include measures already required for the Acme transfer station, such as the construction of sound walls, orienting traffic away from adjoining uses during evening-to-early-morning operations, and regular litter pick-up along access routes. b. SuDDortinq Rationale: The compatibility of a solid waste transfer station land use with other uses is dependent upon where it is located. Transfer stations would be most appropriately located in industrial areas. Other types of land uses would be more likely to be adversely affected by the siting of a transfer station. However, an environmental review for a proposed facility would need to be conducted in order to make such a determination and to identify appropriate mitigation measures. The County Community Development Department is responsible for determining whether a proposed transfer station in the unincorporated area of the County is subject to 8 environmental review. The above impact would be considered in making this determination. During this review, potential adverse impacts to surrounding land uses will be analyzed and mitigation measures identified. Based on this information, the County Community Development Department would implement the appropriate measures by making them Land Use Permit Conditions of Approval. c. MonitorinQ ProQram: The County Community Development Department shall submit an annual monitoring report to the Board on the status of the Conditions of Approval for proposed and sited transfer station projects. II. PUBLIC HEALTH AND SAFETY 1. Impact: Landfill sites have the potential to provide food, cover and breeding ground for disease vectors such as mosquitos, small rodents, and certain species of birds. a. Mitiqation: Compaction and daily cover of refuse would limit birds and rodents from feeding on the refuse. The compaction of refuse in collection vehicles and at landfills effectively controls rodent populations in most cases. If these measures prove inadequate to control rodents and birds, additional measures such as more frequent covering of refuse, scaring of birds, and poisoning or trapping of rodents/mosquitos would be used. b. SuDDortinq Rationale: Studies by the Los Angeles County Sanitation Districts have shown that rats do not survive the compaction process of the refuse trucks or disposal operation. State law requires landfill operators to compact and cover the waste with a layer of soil or new waste in order to minimize the occurrence of rats and other vectors. The requirements are included in landfills' Solid Waste Facilities Permit and may be included in Land Use Permit Conditions of Approval. The County's Health Services and Community Development Departments shall include appropriate provisions in their respective permits. c. Monitorinq Proqram: The County Health Services Department, as the Local Enforcement Agency for the California Waste Management Board, enforces the State requirements for compaction and cover of refuse. Reports of violations are given to the landfill operator and the 5rate. The Community Development 9 Department shall report on the status of these mitigation measures to the Board on a yearly basis. 2. ImDact: Mosquitos could breed in basins constructed to control surface water runoff. a. Mitiqation: In order to mitigate this impact to insignificance, storm runoff from the landfill should be stored in sedimentation basins for short periods such as two weeks. The applicants should coordinate the designs of the basins with the County Mosquito Abatement District to enable easy inspection and spraying of larval suppressant. b. Supportinq Rationale: Mosquito populations could be indirectly increased at a landfill site where sedimentation basins and leachate collection containment ponds would contain standing water for periods of greater than two or three weeks. Prevention of this larval emergence could be suppressed by not allowing water to stand over two weeks and/or spraying the ponds with a non-toxic odorant/colorant such as Golden Bear 1356, which degrades in 48 hours. The County Community Development Department would ensure that the applicant designs and constructs the sedimentation basins in coordination with the County Mosquito Abatement District. The County Health Services Department (HSD) is responsible for determining whether there is a need for spraying to control mosquitos. Appropriate provisions would be included in the landfill's Solid Waste Facilities Permit and/or its Land Use Permit Conditions of Approval. c. Monitorinq Proqram: The County Community Development Department shall obtain reports from the HSD on mosquito problems and abatement at County landfills and include this information in its annual report to the Board. 3. Impact: Operation of a landfill and equipment could cause additional risk of fire. a. Mitiqation: The following typical mitigation measures would be expected to reduce this impact to a less than significant level. Most of these measures are specified by the appropriate fire district, which would be the Riverview Fire Protection District or the East Diablo Fire Protection District (District). Emergency procedures shall be developed and facility employees trained in fire control procedures. One 120,000-gallon water storage tank, a water cannon and stockpiled soil 10 cover will be available on-site for use in fire suppression. Each landfill must have a 100-foot firebreak around the perimeter and at least two emergency all-weather roads maintained by the operator. The earthmoving equipment would be equipped with fire extinguishers and spark arresters, and fuel shall be stored in a safe, approved manner. The operator shall ensure that all incoming loads are inspected for smoldering refuse and that a small fill-area working face be maintained. The Bay Area Air Quality Management District (BAAQMD) requirement that all solid waste landfills monitor landfill gas emissions and install a gas collection system would minimize potential accumulation of methane gas and the associated explosion and fire hazard. As part of a Fire Control Plan, to be reviewed by the Fire Protection District, it should be required to demonstrate the means by which proposed structures on the site will be protected from accumulation of methane gas and associated explosion and fire hazard. b. SuDportinQ Rationale: Fire district requirements will be obtained through environmental review procedures and addressed in the project-level EIRs. A Fire Control Plan, including the above mitigation measures, would be submitted by the landfill applicant and subject to District and County staff approval. Upon final approval of the Fire Control Plan by the District, the Plan would be incorporated into the landfill's Development and Improvements Plan, which will be required as a Land Use Permit Condition of Approval. Compliance to this Plan shall be subject to inspections by the District and the County. c. Monitorinq ProQram: The County Community Development Department shall obtain the inspection and monitoring reports from the appropriate regulatory agencies and include this information in its annual monitoring report to the Board. 4. Impact: Residential and commercial refuse taken to a landfill/transfer station could contain materials that are considered hazardous, which of sufficient quantity might adversely affect air and water quality. a. Mitigation: The following mitigation measures would be expected to reduce this impact. A new landfill or transfer station would accept only non-hazardous municipal refuse, designated wastes allowed by the appropriate Regional Water Quality Control Board, and inert construction/demolition materials through the $tat~-m~ndmt~d periodic load-checking requirement (CCR 11 Title 23, Chapter 3, Subchapter 15). Transfer stations would be required, as is the case for the approved Acme Transfer Station, to provide for the acceptance of household hazardous waste collection and transfer as a condition of Land Use Permit approval. Landfill structural features such as liners, leachate, collection systems, and cover would limit the creation of leachate and reduce the potential for a landfill to contaminate air and water. Further, a comprehensive waste acceptance control program could be established as a part of landfill, transfer station, and collection agreements between the County and individual cities. This program would include the training of franchise haulers and transfer station and landfill employees in the proper identification, handling, storage and disposal of hazardous wastes. b. SuDDortinq Rationale: Despite a wide range of existing Federal and State controls on disposal of hazardous wastes, small quantities of this waste frequently enter the solid waste stream. Health impacts associated with direct contact with toxic materials would pertain primarily to site workers. Indirect effects of the presence in landfills of hazardous waste include intensification of leachate toxicity and mobilization of otherwise stable inorganic metals contained in refuse. This leachate is a greater threat to surface and groundwater supplies (see Impact 5 below). Load checking, household hazardous waste programs, and landfills structural requirements would be addressed in Land Use Permit Conditions of Approval. The County is currently working on a household hazardous waste program to collect, recycle, and properly dispose of hazardous waste and will begin its implementation in Spring of 1990. The County Community Development Department and Health Services Department are responsible for approving a load inspection program for receiving waste loads at landfills/transfer stations in the unincorporated area. The County Health Services Department's Solid Waste Facilities permits pertain to facilities countywide. In addition, the landfill operator must submit quarterly Incoming Waste Reports to the County Health Services Department. The household hazardous waste and waste acceptance control program's are subject to Health Services Department and Community Development Department approval. c. Monitorinq Proqram: The County Community Development Department shall obtain reports on the status of these programs and the compliance to the above mitigation measure, and submit this information to the Board 12 in the annual monitoring report. 5. ImDact: There is a potential for public exposure to hazardous and infectious wastes through leachate contamination of groundwater and off-site surface water. a. Mitiqation, SupDortinq Rationale and Monitorinq Proqram: See Section VIII - Hydrology and Water Quality, Impact 4 of this report. 6. ImDact: There is a potential health and safety hazard to on-site employees of new or expanded landfills from the potentially toxic constituents of landfill gas. a. Mitiqation: This impact would be reduced through compliance to the Bay Area Air Quality Management Dis- trict's requirements. Regulation 8, Rule 34 requires the installation of a gas collection system and the monitoring of gas emissions at all new landfills. The BAAQMD's Air Risk Screening Policy (February, 1988) specifies that a screening analysis for assessment of risk shall be performed as part of the agency's review of landfill permit requests. The extent of gas emissions and the appropriate mitigation measures, such as gas collection and flaring, would be addressed in the individual landfill's site-specific EIRs. b. SuDportinq Rationale: The landfill operator must install a landfill gas control and collection system and perform the necessary testing and reporting of landfill gas emissions. The BAAQMD's Air Risk Screen- ing Policy for toxic emissions, required for an Authority to Construct and Permit to Operate entitlement, must include estimates of emissions for each contaminant, the calculation of the exposure of nearby receptors to ambient levels of the contaminants, and a comparison of these ambient levels with safety thresholds determined by BAAQMD staff. Required installations can be Land Use Permit Condi- tions of Approval. If emission levels do not meet the standards, then remedial measures can be implemented through Solid Waste Facilities Permit provisions to protect employee safety. The County Community Development Department shall be responsible for evaluating landfill gas emissions through the CEQA process and implementing the necessary installations and programs in coordination with the County Health Services Department and the Bay Area Air Quality Management District. c. ~on±tor±nq Froqram: The County Community Development 13 Department shall obtain air emission/compliance information from the BAAQMD's periodic inspections/reviews of the gas collection and ....... monitoring systems at landfills and report this information to the Board in an annual report. 7. ImDact: Transfer stations could recreate the vector, fire, hazardous waste, leachate and landfill gas impacts associated with landfills. a. Mitiqation: The following mitigation measures are expected to reduce these impacts to a less than significant level. Groundwater contaminations from leachate can be controlled because transfer stations are enclosed structures with impermeable, drained concrete flooring. The short residence time of the refuse does not allow for the generation of much gas and the associated flammability and toxicity hazards. Support of vectors is minimized by the short residence time and compaction of waste during handling. Household hazardous waste and waste acceptance control programs will be required at transfer stations to safely and properly manage the collection, storage and disposal of hazardous waste. Implementation of a County household hazardous waste collection program beginning in early 1990 could reduce the volume of this waste currently being illegally disposed of in municipal solid waste. b. SuDDortinq Rationale: Though solid waste transfer stations could potentially have impacts similar to landfills, these impacts are mitigated to an insignificant level by the design/construction of such facilities and the short residence time of the refuse at these facilities. The extent of the problem would be evaluated in site-specific Project Environmental Impact Reports and appropriate mitigation measures would be included in Land Use Permit Conditions of Approval. The County Community Development Department would be responsible for ensuring through Conditions of Approval that the design and construction of transfer stations are adequate to handle solid waste in a manner that mitigates the possible impacts from vectors, fire, hazardous waste, leachate and gas emissions. In addition, the building specifications will be reviewed by the appropriate building inspection and fire district having jurisdiction. Periodic inspections of these facilities would occur as a routine duty of the County Health Services Department. c. Monitorinq Froqram: The County Community Development 14 Department shall report annually to the Board on the implementation of transfer station design and construction. 8. Impact: Waste-to-energy facilities would have the potential for explosions in their processing and storage areas causing safety impacts to plant personnel. a. Mitiqation: Regular inspections of incoming waste, explosive gas warning/detection systems, shielding between waste areas with explosion potential and facility personnel, and installation of pressure relief features in incinerator chambers would be expected to reduce this impact to a less than significant level. b. SuDDortinq Rationale: The improper storage and/or handling of some types of solid waste used as feed- stock in a waste-to-energy plant could result in explosion hazards. Proper design of a plant and employee training in waste handling are essential components in realizing worker safety. Subsequent environmental review of specific waste-to-energy projects may identify additional and/or more specific mitigation measures. The County Community Development Department, Building Inspection Department, the appropriate fire district, and state and federal agencies having jurisdiction, shall address appro- priate design, construction, and operations measures in the facilities' Land Use Permit Conditions of Approval to mitigate potential explosion hazards. The implementation of proper operating procedures would be the responsibility of the plant operators and subject to state, federal, fire district and County Health Services Department review and inspection. c. Monitorinq Proqram: The County Community Development Department shall report annually to the Board on the status of waste-to-energy facility design/construction and operating procedure mitigation measures. 9. Impact: Co-composting of vegetative material and sewage sludge could result in distribution of soil amendment products containing hazardous levels of inorganic metals and disease-causing organisms. a. Mitiqation: In order to reduce this impact, the County shall require that composting operations meet the State Department of Health Services' regulations on land application of sludge and distribution of sludge- amended products. The Environmental Protection Agency (EFA) i~ currently investigating characteristics of 15 municipal sewage sludge and will issue standards for publicly-owned treatment plants. These standards will help to ensure production of sludge amenable to use as a feed stock. b. SuDDortinQ Rationale: Compost would be required to be analyzed by qualified laboratories before its use is authorized. Composting facilities may be required to use pilot facilities to determine whether suitable compost can be produced and under what operating conditions. The CoSWMP recognizes that composting of vegetative wastes, which makeup approximately 13% of the County's solid waste, and its conversion to a usable soil amendment could lead to significant reduction of landfilled waste. Should municipal sewage sludge be used with these wastes, there could be health impacts to humans by exposure to soil-amended products. The EPA's Part 503 technical sludge management regulations were released for public comment in early 1989. These regulations will address exposure to humans to metals in sludge-amended soils, including aggregate health risks posed by several exposure pathways. Until the Federal regulations are in effect, the State guidelines on sludge use for composting will be followed by the County. New landfills are expected to be required to implement pilot level studies of composting to determine if there would be potential problems. c. Monitorinq ProQram: The County Community Development Department shall report annually to the Board on the status of waste-to-energy facility design/construction and operating procedure mitigation measures. III. TRANSPORTATION 1. ImDact: Traffic volumes generated by any of the five landfill sites would add to the current congestion on Highway 4 in the area between Antioch and the Willow Pass Grade. a. Mitiqation: The travel patterns for transfer trucks are adaptable to be managed to reduce or avoid truck trips to the landfill during the peak hours especially the AM peak. Traffic would be minimized by the use of transfer stations and prohibition of self- haulers at the landfill. In addition, there are several highway projects planned that will widen and improve Highway 4 in this area. b. 5uDportinq Rationale; The CoSWMP EIR finds that if 16 truck traffic is managed to avoid the peak hours, there will not be a significant impact to traffic volume on this stretch of roadway. The EIR analysis concluded that during the AM peak hour there would be about ten truck trips eastbound (loaded vehicles) and seven trips westbound (empty vehicles). During the PM peak hour, there would be about two truck trips eastbound and four trips westbound. This analysis reflects the assumptions that transfer stations will be used and self-haulers prohibited from direct access to the landfill. Peak period traffic management study to reduce peak period conflicts with traffic on Highway 4 would be addressed in the site-specific Project EIRs for the individual landfills. The County Community Development Department would require necessary miti- gation measures to be included in the Land Use Permits as Conditions of Approval. The prohibition of self- haulers at the landfill would also be expected to be made a condition of project approval. c. Monitorinq Proqram: The Community Development Department shall include compliance with these conditions in its annual monitoring report to the Board. 2. ImDact: The additional refuse truck traffic, which includes vehicles weighing up to 38 tons, would cause wear and damage to existing roadway pavements in the vicinity of landfills and transfer stations. a. Mitiaation: The project developer would upgrade and improve the pavement sections on the local roads impacted by truck traffic to solid waste facilities. b. SuDDortinq Rationale: In order to reduce this impact to a less than significant level, the pavement traffic index (TI), a measure of the durability and capacity of a road, must be adequate to accommodate the anticipated traffic load. Suitable TIs, in the range of 9.0 to 10.5 for the immediate access roads are expected to be necessary to comply with Caltrans' design specifications. If a 20-year pavement life is determined to be appropriate, a TI of 10.0-10.5 would be required. The landfill project's site-specific EIRs would address the pavement sectionimprovements needed as part of the project. The improvements would be approved by the County Community Development Department and County Public Works Department and CALTRANS if appropriate, and included in the Land Use Permit's Condition of Approval. The improvements called for in this study would be constructed by the developer. c. Monitorinq Proqram; The County Community Development 17 Department shall report annually to the Board on the implementation of the required road improvements. 3. ImDact: The additional refuse truck traffic would cause moderate impacts on the local roads and streets in the vicinity of landfills and transfer stations. a. Mitiqation: The project developer would provide or participate in the funding the necessary roadway and traffic controlimprovements. b. SuDDortinq Rationale: The Program EIR's analysis of each of the five proposed landfill sites shows that the project would not cause any roadway segments or intersections to degrade to a critical level of service. For landfills, this assumes that transfer vans will be used to reduce traffic to and from the landfills. Because the amount of landfill traffic would be low and most of this traffic would not occur during the peak commute periods, the traffic generated by a landfill would not present a significant capacity problem. This traffic may result in additional accidents in proportion to the increased traffic. Specific improvements have been identified for the Acme transfer station and two of the proposed landfill sites in their respective EIR's (East Contra Costa Sanitary Landfill and Kirker Pass Waste Management Landfill) and included in Draft Land Use Permit Conditions of Approval for the sites (the approved conditions for the Acme transfer station). The specific improvements needed for the remaining potential landfill sites and transfer stations would be identified during subsequent project environmental review. Road improvements would be required as Land Use Permit Conditions of Approval. c. Monitorinq Proqram: The County Community Development Department shall submit an annual report to the Board on the status of these traffic mitigation measures. 4. ImDact: There would be an increase in traffic hazards to bicyclists and pedestrians on the local roadways in the vicinity of each solid waste facility. a. Mitiqation: A plan and program to implement a bicycle and pedestrian path system would be required at each landfill/transfer station site to reduce this impact to a less-than-significant level. b. SuDportinq Rationale: The presence of heavy truck traffic on roads with significant bicycle and pedestrian activity can be hazardous. Planned ~uture 18 bicycle paths and pedestrian trails also could be affected by access road improvements. It may be necessary to accommodate bicycling or pedestrian activities by implementing a path system. The project developer would include a bicycle/ pedestrian path in the roadway improvement program for the site if it is determined to be necessary for mitigating potential safety hazards. c. Monitorinq Proqram: The County Community Development Department would ensure that this mitigation is implemented by making it a Land Use Permit Condition of Approval. This department shall include the status of this mitigation measure in its annual monitoring report to the Board. 5. ImDact: There would be potentially significant traffic impacts to the adjacent land uses on the local haul routes used for each site. a. Mitiqation: This impact would be mitigated by the use of transfer stations, by eliminating public access to the landfill, by controlling the hours of truck operation, and by the use of alternate haul routes where possible. b. SuDDortinQ Rationale: This impact is related to the visual and perceived traffic flow (safety and capacity impacts are addressed under Section 1.6, 7, and Section III. 1-4 above). The impact will vary with each site depending on the level of current and anticipated development. By reducing the amount of vehicular traffic on haul routes to landfills through the use of transfer stations and the prohibition of self-haulers, the visual impact will be greatly reduced. Controlling the hours of operation for the remaining truck traffic will help further reduce this impact. Where alternate haul routes are feasible, they would be considered during environmental review in order to minimize impacts to residential development, schools, medical facilities and public areas such as parks. The County Community Development Department would incorporate restrictions on the types of vehicles allowed, the place of origin for such vehicles, and the hours of truck operation into the Land Use Permit Conditions of Approval. Alternative haul routes would be addressed in project-specific EIRs and the one(s) chosen to best mitigate traffic impacts would be written in the Land Use Permit Conditions of Approval as well. ¢. ~onitorinq Proqram~ The County Community Development 19 Department shall submit an annual monitoring report to the Board on the compliance of site operators to these Conditions of Approval. IV. AIR QUALITY 1. Impact: Decomposing wastes in a landfill would create substantial amounts of gas, which includes relatively small amounts of reactive organic compounds (ROG) and chemical compounds considered to be toxic. Downwind receptors could be adversely affected by these compounds. a. Mitiqation: Installation of a gas collection and combustion system would destroy 90% of the ROG and toxic compounds. A risk screening analysis would be required to be conducted on the remaining fraction of these emissions to determine whether downwind receptors are at significant risk from exposure. More efficient gas collection and combustion equipment could be specified if necessary. b. SuDDortinq Rationale: Bay Area Air Quality Management District (BAAQMD) Regulation 8, Rule 34 requires that landfill gas emission and mitigation be controlled and the gas disposed of properly. The most common method of disposal is installation of a gas collection and flaring system to combust the gas. A risk analysis is required prior to BAAQMD's issuance of the Authority to Construct and Permit to Operate a landfill. It must include estimates of emissions for each contaminant, the calculation of the exposure of nearby receptors to ambient levels of the contaminants, and a comparison of these ambient levels with safety thresholds determined by the BAAQMD staff. If the analysis does not demonstrate that the maximum exposure of any individual to an air toxic emitted from a landfill would result in a chance of less than one in a million of developing cancer, then the BAAQMD would require Best Available Control Technology be used to control emissions. The site-specific Project EIRs for individual landfills consider this impact and the specific mitigation measures. The mitigation measures determined to be necessary will become Land Use Permit Conditions of Approval. The County Community Development Department would ensure that project applicants include a gas collection system proposal and submit a health risk assessment as part of their landfill applications. Installation of the collecting/flaring system at all new landfills would be required by the County as a Land Use Permit Condition of Approval, as well as being a requirement of the Day Area Air Quality Management 20 District. c. Monitorinq Proqram: Information from the BAAQMD on compliance of a landfill with air emission requirements shall be obtained by the County Community Development Department and submitted to the Board annually. 2. ImDact: Trace constituents of landfill gas are odorous and could impact people in the area and nearby residences or other sensitive land uses. a. MitiQation: Landfill management techniques, such as daily covering of waste and installation of a gas collection and flaring system, would mitigate this impact. Exceptional problems could be mitigated by more frequent cover and the immediate covering of odorous loads. b. SuDDortinq Rationale: The BAAQMD Regulation 1-301 prohibits the discharge of odorous compounds and the resulting public nuisance, while Regulation 7 provides procedures for evaluating odor complaints. The covering of newly disposed refuse with compacted soil (or other approved means), a requirement of the California Waste Management Board, serves to control odors. The frequency of cover may be increased in order to mitigate odor complaints received by the BAAQMD or County HSD. The gas collection and flaring system reduces odors from landfill gas, composed primarily of methane and carbon dioxide. If the County HSD determines that flaring creates a nuisance, e.g., noise and/or visual impacts, other methods of methane disposal shall be required. The mitigation measures can be implemented through incorporation into the conditions of project approval and through enforcement of BAAQMD and California Waste Management Board requirements. The County Health Services Department is responsible for enforcing odor regulations at landfills and shall make this information available to the County Community Development Department. The Bay Area Air Quality Management District would also perform inspections and enforce its own regulations. c. MonitorinQ Proqram: An annual monitoring report shall be submitted to the Board by the County Community Development Department on implementation of and compliance with these odor control mitigations. 3. ImDact: Construction and operation of a landfill could cause emissions of dust resulting in air quality degradation and impacts to downwind receptors. a. MitiUaLion; Duut emiuuionu are miLlgable wiLh Che 21 following measures: minimizing the extent of un- planted working and graded areas, application of water or an environmentally-safe chemical soil stabilizer to exposed earth surfaces; covering of haul trucks with tarpaulins or other effective covers; and avoiding of unnecessary idling of equipment. b. Supportinq Rationale: Dust emissions related to waste handling can be reduced by approximately 50% by watering surfaces down. Watering should be conducted in late morning and at the end of the day to be most effective. The frequency of watering should increase if wind exceeds 15 mph. The landfill operator's application of water or dust suppressants to working surfaces of the landfill, to its unpaved roads, and to construction areas as determined to be necessary by the County HSD, shall be a condition of the project's Solid Waste Facilities Permit. The HSD would be responsible for requiring additional management practices if problems due to dust emissions are reported. Mitigation measures may also become Land Use Permit Conditions of Approval. c. Monitorinq Proqram: The County Community Development Department shall report to the Board on a landfill's compliance to the dust suppression measures required in its Land Use Permit Conditions of Approval. 4. ImDact: Waste-to-energy facilities could emit significant amounts of both criteria and non-criteria (toxic) air pollutants. a. Mitiqation: The Bay Area Air Quality Management District would specify mitigation measures. b. SuDDortinq Rationale: The BAAQMD requires major stationary sources of criteria air pollutants to comply with New Source Review and Prevention of Significant Deterioration regulations. Under these regulations, any facility that emits any criteria pollutant above specified thresholds must use the Best Available Control Technology (BACT) to reduce these emissions. In addition, the BAAQMD's Air Toxics Risk Screening Policy requires that application for an Authority to Construct and a Permit to Operate a facility include a risk screening analysis of toxic air pollutants. Contra Costa County is a non-attainment area for two of the five non-criteria pollutants, viz., carbon monoxide (CO) and photochemical oxidants (ozone). Therefore, all potential new sources of criteria pollutants must be found to be consistent with the 1982 BAAQMD Bay Area Quality Flan. To accomplish this, BACT may be 22 A required. For toxic air emissions, a health risk screening would be conducted for all landfill proposals (screenings are currently being reviewed for the Keller Canyon and Marsh Canyon projects by the BAAQMD). The County Community Development Department shall be responsible for ensuring that the application and permitting process for these BAAQMD requirements are part of all waste-to-energy proposals and that BAAQMD- required BACT is included as a condition of project approval. c. Monitorinq Proqram: The County Community Development Department shall report to the Board on a landfill's compliance with the air pollution suppression measures required in its Land Use Permit Conditions of Approval. V. NOISE 1. ImDact: Noise resulting from waste handling could disturb nearby residents and sensitive receptors. a. Mitiqation: In order to reduce this impact to a less than significant level, landfill/transfer station hours of operation should be limited to the extent practicable to daylight hours in order to minimize disruption to residential and recreational land uses surrounding the sites. Operations and equipment should be muffled or controlled to meet acceptable noise levels (shown in Table 4.5-2 of the Program EIR). Some additional measures that might be contained in project EIRs include construction of sound walls, earth berms, and on-site truck routing. b. SuDDortinq Rationale: Higher noise levels are generally more acceptable during the day. The construction of a facility, in particular, should be limited to normal working hours as they were for the Acme transfer station, due to the higher levels of noise. Retrofitting existing equipment with noise control features and/or purchasing quieter new equipment for a landfill would, according to the EIR analysis, reduce the radius of disturbance to less than 500 feet. The County Community Development Department would incorporate appropriate noise control mitigation measures into the project's Land Use Permit Conditions of Approval. These conditions may include a noise monitoring and abatement program to be implemented by the facility operator with approval by the County Community Development Department and County Health Services Department. ~. ~onitQr£nq Froqram; Th~ County Community Development 23 Department shall obtain information relating to noise impacts, including complaint reports from the Health Services Department, and compliance of a facility to stipulated noise requirements, and include this information in its report to the Board. 2. Impact: Waste haul trucks entering/exiting landfills, transfer stations, waste-to-energy, or other processing facilities could disturb residents along the site access roads. a. MitiQation: Limiting the hours of access to solid waste facilities and requiring that all haul trucks be filled with operable mufflers and be properly maintained would reduce the likelihood of disturbance to adjacent residences. Specified access routes and the use of transfer stations, which would facilitate control over self-hauler traffic to landfills, would be identified in project-specific EIRs. b. SuDDortinQ Rationale: Restricting truck hauler traffic to daylight hours, when higher noise levels are more acceptable, would help offset the impact from the projected increase of solid waste facility generated noise. According to Table 4.5-3 of the EIR, this increased level of noise ranges from 2-5 decibels Ldn (day-night average noise level over a 24-hour period) along selected roadways leading to alternative landfill sites. Other measures that might be recommended in project EIRs include noise shielding along routes and active enforcement of muffler and vehicle noise standards by police services. The County Community Development Department shall incorporate appropriate noise control mitigation measures into the conditions of project approval. These conditions may include a noise monitoring and abatement program to be implemented by the facility operator with approval by the County Community Development Department and County Health Services Department. c. MonitorinQ ProQram: The status of this requirement shall be reported by the Community Development Department in its annual monitoring report to the Board. VI. VEGETATION AND WILDLIFE 1. ImDact: Landfill development could increase the variety and number of weedy plant and pest wildlife species. a. MitiQation: Implementation of a weed control program 24 at the site would typically include a list of noxious weeds, periodic monitoring for these species, and a weed control and removal program via physical removal, prescribed burning and/or limited application of herbicides. Daily covering of the landfill would help control potential pest problems. A pest control program should be developed to be implemented if problems occur and would include a list of pests, methods to be used for control of them, and a monitoring program to evaluate the effectiveness of the program. b. SuDportinq Rationale: Landfills are often populated by non-native, invasive weeds and pests. This intrusion could adversely impact the native species populations, especially when a landfill is close to regionally significant open spaces like regional parks, and could become a potential source of diseased vectors. Proper operation of a landfill, including daily cover and compaction of waste and a weed control and pest control program, does not provide for a suitable habitat for propagation or survival of non-native species. The use of pesticides and/or fumigants should only occur as a last resort and with the approval of local and State public health and natural resource agencies. The County Community Development Department would ensure that a weed control and pest control program, if needed, is developed and implemented by making it a Land Use Permit Condition of Approval. The Health Services Department would monitor the pest control program. c. MonitorinQ ProQram: The County Community Development Department shall report to the Board annually on the status of weed and pest control mitigations at landfills. 2. ImDact: Landfill sites located within or adjacent to natural waterways could impact riparian and other vegetation through soil erosion if there is inadequate revegetation of cover areas. Stream erosion could occur below the fill area if runoff is significantly increased. a. Mitiqation: Erosion control planting should be undertaken on both intermediate and final cover areas immediately as portions of the landfill close. Inactive areas, even if only temporary, should be planted. Check dams with sedimentation basins should be placed, if needed, in the stream channel below the landfill footprint (fill area). An erosion control and hydrology plan coordinaLing the~e mea~ure~ would be 25 developed for each landfill site. b. SuDDortinq Rationale: Landfill development could result in increased stormwater runoff, increased erosion, and subsequent sedimentation and increased turbidity in the runoff and in the waterway below the fill area. This process would disturb riparian and other vegetation. Application of planted groundcover would help to hold the soil in place. Sedimentation basins would control the rate of release of stormwaters and reduce turbidity. An erosion control plan would identify plant materials and methods to be used in revegetation efforts, identify where erosion control structures would be located, and estimate the flow changes downstream of the site to determine whether it could result in significant erosion or vegetation problems. An erosion control/surface water monitoring plan, approved by the County Community Development Department, and coordinated with the County Public Works Department and the appropriate Regional Water Quality Control Board, would be required by the Land Use Permit Conditions of Approval. c. Monitorinq Proqram: The County Community Development Department shall obtain all applicable information on the implementation and monitoring of the revegetation and erosion control programs at landfills and report it to the Board annually. 3. Impact: Landfill construction activities would displace or cause the death of some wildlife in and adjacent to the proposed fill areas. a. Mitiqation: In order to reduce the impact of landfill activities on wildlife, the landfill would be constructed and operated in phases that limit clearing to areas needed for immediate use, and grasses and other vegetation would be planted after project completion to aid in accommodating wildlife in the area. b. SuDDortinq Rationale: Phased construction would limit the amount of land disturbed at any one time to a minimum. This would reduce the acute impact to wildlife, as habitat would be lostgradually, thus giving the wildlife time to relocate and regenerate. Testing of soils to be replaced in completed areas should be required to determine the need for adding nutrients and/or other soil amendments to enhance revegetation and restoration of wildlife values. A habitat protection and enhancement plan would be required as part of the Land Use Permit Conditions of 26 Approval for any landfill. This plan would be prepared by a qualified biologist in consultation with the California Department of Fish and Game, and where appropriate, East Bay Regional Park District. The plan would, to the extent possible, replace and/or enhance the wildlife habitat lost to landfill operators. c. Monitorinq ProQram: The County Community Development Department would be responsible for ensuring that this condition is met and implemented, and would report to the Board annually on the compliance of the landfill developer with this plan. 4. ImDact: Landfill activities could cause the release of toxic materials to downstream areas resulting in degradation of aquatic and riparian habitats. a. Mitiqation: To reduce this impact to a less than significant level, a leachate collection and recovery system would be installed at each approved landfill site. A monitoring program would assure that the system is working properly. If it is discovered that downstream areas are being adversely affected, a remedial plan shall be implemented to correct the problem. b. SuDDortinq Rationale: In addition to a leachate collection system, a highly impermeable soil layer and/or a synthetic plastic liner is required at all Class II landfills. The Contra Costa CoSWMP calls for all new landfills to be designed and constructed to Class II standards. The combination of these two requirements would be expected to reduce the potential impact of a toxic material release to insignificance. Water quality mitigation programs are discussed in more detail in Section VIII of the Program EIR. The County Community Development Department would ensure that all new landfills in the County are designed to the requirements of Title 23, Chapter 3, Subchapter 15 of the California Code of Regulations (Subchapter 15) regarding leachate collection and bottom liner systems. The monitoring program required by the RWQCB would be subject to sampling and analysis of groundwater wells in order to provide an early warning of toxic release to downstream areas. c. Monitorinq Proqram: The County Community Development Department shall obtain the well testing reports from the RWQCB and include this information in its annual monitoring report to the Board. 5. ImDac%; Landfill construcEion and grading activities could 27 indirectly impact vegetation not removed directly by construction. a. MitiQation: Vegetation that is to remain on-site (outside the fill area) would be protected by the dust control measures to minimize air quality impacts (to help prevent damage to vegetation from dust deposition). To prevent plant life from being adversely affected by dust settling on leaves, periodic watering, as an extension of dust suppression mitigation, should be used to clean the vegetation. b. SuDDortinq Rationale: The County would require a Habitat Protection and Enhancement Plan as a Land Use Permit Condition of Approval which would give priority to the use of the site, except where landfill operations and appurtenant facilities are located, for the preservation and enhancement of plant and wildlife habitat. c. Monitorinq Proqram: The County Community Development Department shall be responsible for ensuring that these conditions are complied with and report its findings to the Board annually. 6. ImDact: Diversion of solid waste to existing County landfills could impact sensitive plant and annual species occurring there. a. Mitiaation: Biological field surveys would be conducted at sites proposed to be expanded to determine the existence of any sensitive species. If found, appropriate mitigation measures would be developed by a qualified biologist at the time the expansion Project EIR is proposed. b. SuDDortinq Rationale: Due to the present use of the existing landfills, it is unlikely that these sites support sensitive plant and animal species. However, a suitable biological survey should be conducted to ascertain whether this is the case. The County Community Development Department shall require a biological field survey during the environmental review process for any proposal to expand an existing landfill to divert waste to an existing County landfill. c. Monitorinq Proqram: The County Community Development Department shall submit reports to the Board, when applicable, on the status of this requirement as it relates to proposed waste diversion projects. VII. GEOLOGY, SOILS AND SEISMICITY 28 1. ImDact: Landslide activity on fill or cut slopes and unstable natural slopes could occur as a consequence of site excavations and earthwork construction, causing structural damage and endangering lives. a. Mitiaation: The following mitigation measures would be expected to reduce these impacts to less than significant levels: 1. Potential slide areas would be drained to keep slip surfaces dry, and unstable earth materials would be excavated and landfill used to buttress landslide areas. 2. A slope monitoring program would be implemented during operation. 3. The applicant would perform a site-specific static and seismic stability analysis as part of the final design, approved by the County. 4. Cut slopes would be designed to consider adversely oriented joint surfaces, existing shallow landslide deposits and other relevant geotechnical factors under static and seismic conditions. 5. Use of conservative geotechnical engineering practices and stabilization measures during excavation of areas of landslide activity. 6. Monitor slopes with adversely oriented bedding surfaces or joint surfaces through a metering system. 7. As conditions of project approval previously stipulated by Contra Costa County, a Landslide Study and a Slope Monitoring Program would be undertaken by a California Certified Engineering Geologist, or by a qualified team. The Study and Program would be incorporated into the final design for the project. b. SuDDorting Rationale: Hillside and fill/cut slope failures in natural materials and in the landfill can be minimized by maintaining maximum strength of the materials and by increasing forces that resist sliding and slope failure. The County Community Development Department would ensure that the above geotechnical investigations are conducted during project environmental review, and that appropriate mitigation measure8 are included in the pro]ect's Land Use Fermit 29 Conditions of Approval. A geotechnical inspector responsible to the County would be present when sensitive grading and installations are performed. c. Monitorinq Proqram: Reports on the implementation of these measures and from the on-site monitoring programs shall be obtained by the County Community Development Department and included in the annual monitoring report to the Board. 2. ImDact: Engineered surfaces and slopes within the landfill footprint could be subject to excessive fill settlement and/or localized slope sloughing resulting from decomposition of refuse, causing potential slope failure and rupture of seals. a. Mitiqation: This impact would be expected to be reduced to a less than significant level through the following measures. The refuse and cover materials would be compacted to maximum strength. The landfill slopes would be engineered to provide stability under design criteria. The infiltration of water would be controlled through drainage features, lateral barriers and intermediate and final covers. Heavy equipment would be operated so as to minimize vibrations. Cover soil would be stockpiled outside the fill area. As a condition of project approval previously stipulated by the County, the landfill developer could be required to install a network of settlement platforms to detect and correct settlement problems. The developer would provide a stability analysis of the final engineering design of the landfill and its appurtenant improvements. b. SuDDortinq Rationale: The above mitigation measures are required by the RWQCB and the County to mitigate the potential effects from refuse decomposition. This impact could be exacerbated by the variable density and strength of earth materials underlying much of the upland areas of the County. The County Community Development Department would include the above landfill practices for mitigating potential impacts from fill settlement in the Development and Improvements Plan of the Land Use Permit Conditions of Approval. c. Monitorinq Proqram: The County Community Development Department shall obtain all applicable reports on the implementation, monitoring and enforcement of these requirements, from the geotechnical inspector, the County HSD, and the RWQCB, and include this information in its annual report to the Board. 3. Impact; ~xc~88ive ~tockpiling of loose soil could result in 30 slope instability, causing sedimentation and possibly damaging structures and endangering lives. a. MitiQation: A stockpile stability monitoring program would reduce this impact to a less than significant level. b. SuDDortinq Rationale: The landfill operator would continually analyze the on-site stockpiles of daily cover material to determine the maximum allowable heights and/or slopes for stability. This monitoring would commence at the on-set of stockpiling. The County Community Development Department would include this mitigation measure in the Slope Monitoring Program as a Land Use Permit Condition of Approval.Monitoring Program: The landfill operator will make the results of this monitoring program available to the County Community Development Department on demand. The County Community Development Department will report on the status of this program to the Board annually. 4. Impact: Adequate amounts of general cover materials for low permeability soils for final cover might not be available on a landfill project site, causing off-site quarrying impacts such as excavation slope instability and depletion of mineral resources at the source of borrow materials. a. Mitiqation: To reduce these impacts to less than significant levels, the following mitigation measures would be considered for implementation by the County. The RWQCB requires that on-site cover soil be compacted to decrease its permeability and, if necessary, it can be amended with additional compacted soil or other material such as bentonite. If supplies are not available on-site, low permeability materials would be imported to provide cover. The Program EIR originated these additional measures: soils that meet Subchapter 15 permeability requirements should be selected and stockpiled for use as a final cover; soil borrow source areas should be evaluated with respect to State mineral resource zoning programs and regional resource classification and designation plans to resolve questions of resource supply and demand; slope stability of stockpiled soils should be addressed (see Section VII Impacts 1, 2 and 3 above). Consideration also may be given to cover substitutes, such as commercial landfill foam. b. SuDDortinq Rationale: The site geotechnical investigations, including soil borings, required by the landfill developer during the application process would determine the amount o~ soil cover material available 31 on the site. Proposals to use cover substitutes or to excavate off-site soils for cover would be subject to environmental review. The County Community Development Department would require that an adequate supply of landfill cover material that meets the RWQCB permeability standard be available before it issues a Land Use Permit for a landfill. The proper hauling and storing of this material would be addressed in project- specific EIRs and would become part of the conditions of project approval. c. MonitorinQ ProQram: The County Community Development Department will report to the Board annually on the project's compliance to these requirements. 5. ImDact: The shrink/swell behavior of expansive foundation soils could deform building and landfill structure foundations. a. Mitigation: This impact would be expected to be reduced to a less than significant level by adherence to geotechnical recommendations, such as the use of pier and grade beam foundations and/or the replacement of native soils with compacted non-expansive soils. b. SuDDortinQ Rationale: All nine Soil Conservation Service soil classifications in the County have soils with highly expansive properties. Engineered solutions to ensure that a solid waste landfill or facility's foundation and/or structural integrity is not compromised are necessary. The particular solutions will be contingent on the geotechnical studies of site- specific proposals. The County Community Development Department is responsible for ensuring that adequate engineering design for a landfill or facility's structural integrity be included in all project- specific proposals and made a Land Use Permit Condition of Approval. The Conditions of Approval would be expected to require a geotechnical inspector to be present on-site when sensitive installations are performed. c. Monitoring Program: The County Community Development Department shall obtain all relevant information from the inspector, the RWQCB and the County Department of Public Works on the compliance of a facility to these conditions and include it in its annual monitoring report to the Board. 6. Impact: Highly impermeable soils could allow water to pond 32 beneath solid waste facility building foundations, causing a deformation of these foundations. a. Mitiqation: Use of standard Uniform Building Code grading procedures to direct drainage away from buildings would reduce this impact to a less-than- significant level. b. SuDDortinq Rationale: Highly impermeable soils occur at most of the proposed landfill/facility areas. These types of soils could pond water, swelling expansive soils and/or saturating and weakening foundation soils. Directing water away from building foundation soils with the use of such techniques as drainage ditches/culverts and grading to convey surface run-off water away from facility buildings would prevent the ponding of water. The facility developer would be required to submit a project proposal, which describes the placement and construction of the drainage system to be used on the site, as part of the Development and Improvements Plan. This would be evaluated in the project's Environmental Impact Report. Mitigation measures would be incorporated into the Land Use Permit Conditions of Approval. c. Monitorinq Proqram: The Contra Costa County Community Development Department and Building Inspection Department would oversee the implementation of this site plan and the County Community Development Department shall include this information, when applicable, in its annual monitoring report to the Board. 7. Impact: Groundshaking from off-site earthquakes could damage the landfill's containment and drainage features and/or cause slope failure. a. Mitiqation: The following measures would be expected to mitigate this impact to a less-than-significant level. The landfill and drainage features would be designed to withstand ground accelerations from a maximum credible earthquake, as required by the State for Class II landfills. The proposed final engineering design for the landfill, including face slope gradients, operating components and appurtenant improvements, shall be reviewed for resistance to the current design earthquake standards. An emergency program for inspecting the landfill facility, addressing the possibility of failures and interim refuse handling, would be developed for implementation following a substantial earthquake. A study of the faults that could affect slope stability and 33 groundwater movement at the site shall be performed and incorporated in the final site program and design of structures. A dam failure prevention and warning system program, including daily monitoring, for the sedimentation ponds would be prepared and implemented, as a Land Use Permit Condition of Approval. b. SuDDortinq Rationale: Where active fault traces are suspected to exist, fault rupture along the trace would be mitigated through set-back recommendations in site- specific geotechnical investigations. State siting criteria for Class II and Class III solid waste facilities require that structures be located off the trace of any active fault. The maximum credible earthquake for a proposed facility would be identified during geotechnical review of the site. Seismically- induced landsliding at proposed permanent cut areas would be mitigated by appropriate slope gradients or subdrained concrete retaining structures, engineered and designed according to Uniform Building Code and the California Structural Engineers Association standards. The above-referenced geotechnical studies and emergency/monitoring programs would be developed by the landfill developer, approved by the County, and incorporated into the Land Use Permit Conditions of Approval. c. Monitorinq Proqram: The County Community Development Department shall obtain all applicable reports on the implementation, monitoring and enforcement of these requirements, from the geotechnical inspector, the County Health Services Department and the RWQCB, and include this information in its annual report to the Board. VIII. HYDROLOGY AND WATER QUALITY 1. ImDact: Landfill development involving the excavation and stockpiling of soil could result in soil erosion and subsequent increased turbidity in run-off and the sedimentation of drainageways. a. Mitiqation: This impact would be expected to be fully mitigated by the routing of drainage water through sedimentation basins to be located at the downstream end of the canyon proposed for landfilling. In addition, review and approval by the County of an erosion and sediment control plan shall be required of the developer prior to issuance of a grading permit. b. $UDDortinq Rationale: All stormwaters would be routed 34 through these basins and detained for a sufficient time to allow the excess turbidity to settle out. A routine maintenance plan would be required to ensure the continued proper functioning of this basin system. The erosion control plan would ensure, among other things, that eroded sediments are trapped before entering the constructed drainage channels and that stockpiled soils are sufficiently stabilized. A sedimentation basin system and sediment and erosion control plan would be required by the County Community Development Department as a Land Use Permit Condition of Approval, on the basis of the project's site-specific EIR. It would be developed and implemented by the landfill developer, with the approval of the County Community Development Department, County HSD and Public Works, and the RWQCB. c. Monitorinq Proqram: The County Community Development Department shall report on the status of these mitigation measures in its annual monitoring report to the Board. 2. ImDact: Failure of the sedimentation/detention basins when full or nearly full would pose a hazard to downstream areas. a. Mitiqation: In order to reduce this impact to a less- than-significant level, all sedimentation/detention basins would be designed and constructed according to Class II requirements. The basins would be inspected regularly by the State Department of Water Resources for those dams over 25 feet high and storing over 50 acre-feet of water. b. SupportinQ Rationale: The sedimentation/detention basins should be designed for a 1,000-year, 24-hour storm intensity and should be capable of withstanding the maximum credible earthquake identified for the site. The County Community Development Department would be responsible for ensuring that a landfill sedimentation basin system included in a project would meet all State and County requirements by making compliance a Land Use Permit Condition of Approval. c. Monitorinq Proqram: The County Community Development Department will report annually to the Board on the implementation of this system, including the preventive maintenance program to be developed by the landfill operator. 3. ImDact: Replacement of natural drainage with a man-made system could result in increased stormwater run-off, erosion and subsequent sedimentation and increased turbidity. a. Mitiqation: The installation of sedimentation/ 35 detention basins would reduce these impacts to less than significant levels by controlling the rate of release of stormwaters and reducing turbidity. b. SupDortinq Rationale: The existing natural drainages would be replaced by man-made drainage channels to keep stormwater from ponding over the landfill site. This re-routing of run-off would also help avoid the generation of leachate. Basins would be needed to hold and control the rate of release of these stormwaters in order to prevent downstream erosion and increased sedimentation and turbidity. Regular inspection and maintenance would be conducted to ensure proper functioning of the system. Moreover, Class II landfills are required by State law (Subchapter 15) to be designed, constructed, operated, and maintained to prevent inundation or washout due to a 100-year flood. Final site design, sediment and erosion control, and surface drainage system plans must be developed and implemented by the landfill developer, with the approval of the County Community Development Department, County HSD and Public Works, and the RWQCB. The County's requirements would be imposed by the project's Land Use Permit Conditions of Approval and would be monitored by the above agencies. c. Monitorinq Proqram: The County Community Development Department shall report on the status of these mitigation measures in its annual report to the Board. 4. ImDact: Landfill leachate could contaminate surface water or groundwater with which it comes into contact. a. Mitiqation: The following measures would be expected to reduce this impact to a less-than-significant level. To prevent surface water contamination, rain falling on the landfill would be isolated from the refuse by a system of slopes, drainage benches, drain ditches and sedimentation basins. Final grading and cover would allow proper drainage so that water would not pond over the landfill. Groundwater protection would be ensured by the landfill being constructed and operated according to Subchapter 15 requirements. A minimum of five feet vertical separation between the landfill base and the historic high groundwater or perched water elevation is required. Installation of a low- permeability clay liner or a composite liner (synthetic plastic), a subdrain system, and a leachate control and removal system would comply with these regulations. All landfills would be required to have a groundwater monitoring program to provide early warning in the event o~ leachate migration £rom the land£±11. The 36 RWQCB would limit the disposal of "wet" wastes such as sludges on a site-specific basis. b. SuDDortin~ Rationale: All detention and sedimentation basins at a landfill site would be designed to accommodate the 1,000-year design storm as required for a Class II landfill. To meet Subchapter 15 criteria, a landfill liner for Class II sites must have a water permeability no greater than 1 x 10-6 cm/second. The leachate collection system would be designed to transport all excess leachate to a point where it could be removed and disposed of properly, according to a leachate management plan required by the County. The groundwater monitoring program would be developed in concert with the RWQCB and likely involve quarterly sampling and analysis of upgradient and downgradient wells. The landfill operator shall comply with the requirements of the RWQCB for disposal of de-watered sewage, and other utilities' sludges in landfills to prevent excess liquid disposal. Other liquid wastes shall not be accepted at landfill. The County Community Development Department would ensure that State and RWQCB requirements on water protection from leachate will be complied with as conditions in a project's Land Use Permit. An independent geotechnical consultant, responsible to the County, would be expected to be required by the Land Use Permit to inspect regularly over the life of the landfill the installation and condition of liners and leachate control facilities as they are installed. c. Monitorinq Proqram: The County Community Development Department shall obtain all relevant information on the compliance of the landfill with these requirements from the appropriate agencies and include it in the annual report to the Board. 5. Impact: The water supply requirements for a landfill might not be available on-site, thus requiring the procurement of off-site water. a. Mitiqation: A public water source for some or all of a landfill's needs would require a connection to Contra Costa Water District (CCWD) facilities. Annexation to the CCWD service area would require approval by the CCWD, possibly a city, and the Local Agency Formation Commission. b. SuDDortinq Rationale: The generally poor quality of on-site water (unsuitable for drinking) would be adequate for most landfill activities such as compaction, dust control, and fire suppression. The 37 EIR recommends exploring the feasibility of utilizing sub-potable supplies such as reclaimed wastewater, on- site stormwater retention, or connection to a non- potable public water supply systems. A connection of the latter kind could be considered to be non-growth- inducing. The County Community Development Department requires that the landfill developer submit a water service plan covering available water resources, estimated total water needs and supplies, landfill construction and operation, landscaping, fire protection, employee hygiene, human consumption water needs, and water supply sources. It is evaluated in the project's EIR and resulting mitigation measures are included in the Land Use Permit's Conditions of Approval. c. Monitorinq Proqram: The County Community Development Department shall report annually to the Board on the compliance of proposed and sited landfills to this water service plan requirement. 6. ImDact: Inundation of transfer stations would cause adverse impacts to the structure and to water quality. a. MitiQation: All transfer stations and solid waste processing facilities should be located outside of the 100-year floodplain. b. Supportinq Rationale: The 100-year flood area is defined by the Federal Emergency Management Agency. This requirement could be met by such design features as berms, drainage systems, ponds, and elevation above flood levels to prevent floods from contacting the refuse on site. Location relative to floodable areas is addressed in projects' Environmental Impact Reports. The Community Development Department would ensure that the siting of transfer stations and related facilities include measures to prevent inundation from a 100-year flood event. Appropriate mitigation measures would be included in the final site design plan, as part of the project's Land Use Permit Conditions of Approval. c. Monitorinq Proqram: The County Community Development Department shall report annually to the Board on this siting criteria as it applies to proposed and sited facilities. VISUAL QUALITY 38 1. ImDact: A solid waste facility's on-site operational lighting could create glare and visual disturbances to nearby off-site land uses. a. MitiQation: To mitigate the effects of this impact, lighting should be designed (e.g., through downward- oriented reflectors) and placed to reduce glare under full operating conditions and should be dimmed or turned off, except for security lighting, during late hours of darkness. Full operational lighting may be limited to normal operational hours of the facility. Focused directional security and operational lighting should be installed as part of the project. Excessive lighting of the access and operational areas should be avoided. b. SuDDortinQ Rationale: Construction and operational lighting would increase ambient light and glare due to night lighting. Lighting and hours of operation restrictions would be addressed during project design and review. The County Community Development Department would ensure that construction and operational lighting of a solid waste facility does not substantially impact nearby land uses by including the appropriate mitigation measures in Land Use Permit Conditions of Approval. The County HSD could also specify hours of operation in the Solid Waste Facilities Permit and respond to lighting complaints by nearby residents. c. Monitorinq Proqram: The County Community Development Department shall report annually on the implementation and enforcement of these requirements to the Board. 2. ImDact: Excavation and filling activity at a landfill site would substantial alter the natural topography and appearance of the area. a. Mitiqation: To mitigate this impact, visual berms could be installed at the toe level and/or at the faces of lifts; the area of active operation could be limited to approximately 20-25 acres at any one time, except when major modules are being prepared and foundation improvements installed. Covered layers of refuse could be graded and contoured to replicate the form of the existing surrounding terrain. Revegetation of completed fill areas and areas to be inactive for more than 90 days could be required. b. 5uDDortinq Rationale: A landscaping and screening plan 39 based on the applicant's project description and project EIR mitigation measures would be required as part of a final site plan. It would detail the locations and configurations of grades and contours, screen plantings, overall site landscaping, and revegetation efforts. The County Community Development Department would ensure that these plans are prepared and implemented by the landfill developer by including them in the Land Use Permit Conditions of Approval. c. MonitorinQ ProQram: An annual compliance report on these conditions shall be submitted by the County Community Development Department to the Board. 3. ImDact: Construction and operation of a landfill would result in the removal of existing vegetation. a. Mitiqation: The planting of temporary or permanent vegetation to match the existing visual character following placement of each portion of intermediate or final cover on filled areas would mitigate this impact. b. SuDDortinq Rationale: Restorative landscaping may appear to clash with the existing visual character of the native plantings or may be planted in unnatural plant groupings. Thus, trees, shrubs and broadleaf species which are currently found in the site area or are native to the area should be planted on filled areas. In addition, the County would require the planting of annual grasses as temporary cover and perennial grasses as permanent cover which can be used later for grazing. As a condition of approval for the project's Land Use Permit, the landfill developer shall prepare and implement a final landscaping plan, as part of the site design plan, which shows plant species, size and locations, a maintenance program, and any landscape mitigation measures identified in the project-specific EIR for the site. This plan is subject to County Community Development Department approval. c. Monitorinq ProQram: The County Community Development Department shall submit an annual monitoring report to the Board on the compliance of a proposed or sited landfill to this requirement. 4. ImDact: Landfill operations may be visible from off-site residential and recreational areas, as well as from travel corridors. a. Mitiqation: This impact can be mitigated by utilizing 40 natural topography as a visual barrier and by providing visual buffers, such as noise/visual berms along the active landfill operation, and by providing screening elsewhere on the site. Corporation yards and staging areas should be constructed away from public view if possible. Views from roadways, especially scenic routes, would be screened by installing dense plantings along the roadway or elsewhere on the site where the screening is most effective. b. SuDDortinq Rationale: Since all of the proposed landfills are located in canyons, topography will provide visual screening to some degree. This natural screening can be enhanced by installing berms and screens. Earth berms are an effective visual buffer for screening views to a landfill. The form of the berms could mimic the natural line of the area's hills. Berms would be landscaped with perennial grasses and native trees and shrubs as appropriate. Planting patterns could be naturalistic. The County Community Development Department would ensure that visual mitigation measures identified in the project's EIR are included in its Land Use Permit Conditions of Approval. The landfill developer would be required to prepare and implement a final landscaping plan with the approval of the County Community Development Department. c. Monitorinq ProQram: The County Community Development Department shall submit an annual monitoring report to the Board on the compliance of a proposed or sited landfill to this requirement. 5. Impact: Windblown debris and litter from a solid waste facility could result in an adverse visual impact and/or could be carried to off-site locations. Illegal dumping near a facility entrance could visually detract from the appearance of the surrounding area. a. Mitiqation: The following mitigation measures would reduce these impacts. Eliminating self-haulers to new landfills would reduce littering on their sites and on access roads. The landfill operator might be able to align refuse unloading areas away from the prevailing wind direction. Refuse would be covered at least once a day, and could be covered more often, depending on wind velocity. Installation of portable fencing near the working area and a permanent fence around the landfill site periphery to intercept and contain windblown debris would be required. Litter would be collected from the litter fences and planting screens on a daily ba~±~ and from along access roadways as 41 often as in deemed necessary by the County. The landfill operator would post signs along access roads noting littering and illegal dumping laws; signs at the entrance would note hours of operation. Policing of the site and entrance area would be required on a daily basis or more often, if needed. The landfill operator would implement a program to limit uncovered loads, possibly including a higher charge for these loads to help off-set the cost of monitoring litter collection. Litter control rules should be periodically published in newspaper advertisements or mailed flyers. b. SupDortina Rationale: The County Community Development Department would incorporate a litter control plan generally including the above mitigation measures into the project's Land Use Permit Conditions of Approval for all new landfill and transfer station facilities. The County HSD would have the authority to enforce this plan. c. MonitorinQ ProQram: A quarterly monitoring report shall be submitted to the Board by the County HSD on the compliance of solid waste facilities to these regulations. X. SOCIOECONOMICS 1. ImDact: The siting of a solid waste facility could adversely affect the value of property located in the vicinity of the site. a. Mitigation: The mitigation measures listed in other sections of this report, especially those that relate to odor control, dust control, litter control, landscaping and traffic control are expected to reduce this impact to an insignificant level. b. SuDDortinq Rationale: In three separate studies on the effects of landfills on surrounding property values, the conclusions were as follows: solid waste disposal sites have no apparent negative effect on change in property value of single family homes in their immediate vicinity (The Effects of Solid Waste Disposal Sites on Property Values, 1972); property characteristics other than distance to the landfill appear much more important in explaining prices (Pennsylvania State University, Effects of Solid Waste Disposal Sites on Community Development and Residential Property Values, 1982); and proximity to the landfill had a negligible impact on initial sales pricing of recently constructed homes (Property Value Impact 42 Study, Puente Hills Landfill, 1983). As part of the complaint program, a County representative could meet with local homeowners' associations or organize neighborhood meetings to ensure that an appropriate response is received. The County Community Development Department would incorporate the appropriate mitigation measures suggested in the CoSWMP EIR, as well as those identified in project-specific proposals, into the Land Use Permit conditions of approval for a project. c. Monitorinq Proqram: As stated throughout these findings, the County Community Development Department shall submit monitoring reports to the Board on a regular basis regarding the implementation, monitoring and enforcement of the identified mitigation measures. XI. CULTURAL RESOURCES 1. Impact: Previously unknown cultural resources at potential landfill, transfer station, or resource recovery facilities could be impacted during construction. a. Mitiqation: In order to reduce this impact to a less- than-significant level, the following measures would be taken. If an historic site is discovered during construction, work would temporarily cease to allow a site evaluation. Concurring field and archival research would be undertaken by an historic archaeologist to determine the quality and quantity of information relating to site occupation, and the extent, integrity, and diversity of archaeological remains. Should this testing phase indicate that the site could yield additional information of importance to area history, then a date recovery phase may be warranted. This phase could include further archival or oral history research, excavation of a sample of the site, or combinations thereof. If significant deposits are not encountered, the testing phase could be considered adequate mitigation. Project-related indirect impacts to known sites in the vicinity of the proposed facility sites can be mitigated by 1) limiting employee access to off-project areas and enforcing a strict prohibition against artifact collecting or vandalism; 2) limiting construction vehicle movement to road surfaces that have been subject to previous survey; and 3) consulting an archaeologist prior to conducting any off-project activities (road construction, drainage control, pit construction) that may not have been subject to previous archaeological surveys. b. SuDportinq Rationale: Historic areas have been ~ound 43 within an adjacent to some of the propose landfill site areas. These have been surveyed and mitigation measures identified in the project EIRs. c. Monitorinq Proqram: The County Community Development Department shall incorporate appropriate cultural resource mitigation measures identified in the project EIRs into the conditions of project approval. On-site mitigations shall be approved in conjunction with the Regional Clearinghouse of Sonoma State University and a qualified archaeologist shall oversee their implementation. The County Community Development Department shall report annually to the Board on the applicability of cultural resource findings and mitigation measures as they apply to proposed and sited solid waste projects. XII. PUBLIC SERVICES 1. Impact: Landfills and transfer stations could increase the risk of fire. a. Mitiqation, SuDDortinq Rationale, and Monitorinq Proqram: See Section II. Public Health and Safety, Impact 3 of this report. 2. ImDact: Disposal of landfill leachate could adversely impact wastewater treatment systems. a. Mitiqation: The RWQCB requires that landfill developers prepare and implement a disposal plan for leachate with the appropriate wastewater treatment agency prior to construction of the landfill. In most cases, the disposal plan would require on-site treatment of the leachate to meet RWQCB standards prior to its introduction into the wastewater system. b. SuDDortinq Rationale: The County Community Development Department would ensure that all RWQCB requirements are met during environmental review of proposed landfills. The disposal means (mitigation measures) would also be included in the landfill's Land Use Permit Conditions of Approval and may be specified in the County Services Department's Solid Waste Facilities Permit as well. c. Monitorinq Proqram: The County Community Development Department shall obtain reports from the RWQCB and appropriate wastewater treatment agencies on compliance of a landfill facility to the disposal plan, and make this information available to the Board on an annual basis. 44 3. ImDact: Construction and operation of a landfill would require large quantities of water which may impact local groundwater supplies or the supplies of a public water supply utility (the Contra Costa Water District). a. Mitiqation: As previously noted, the landfill developer would propose a water service plan, covering available water resources, estimated total water needs and supplies, landfill construction and operation, landscaping, fire protection, employee hygiene, human consumption water needs, and water supply sources. Specific mitigation measures would be identified in project-specific EIRs. b. SuDDortinq Rationale: The water plan would be based on verified supply information. Water for operation could be obtained either from on-site drilling of deep wells or on-site collection of surface drainage. If on-site water is not adequate, water for construction might be obtained from off-site sources. Use of Contra Costa Water District (CCWD) water would require its approval, possibly that of a city, and the Local Agency Formation Commission's approval. The County Community Development Department would evaluate the landfill developers' water service plans in the project's site- specific EIRs, and include mitigation measures as Land Use Permit Conditions of Approval. c. Monitorinq Proqram: The County Community Development Department shall report annually to the Board on the compliance of proposed and sited landfills to this plan and/or its implementation requirements. POTENTIALLY SIGNIFICANT IMPACTS WHICH MAY NOT BE MITIGABLE TO INSIGNIFICANT LEVELS The Board of Supervisors finds that the following impacts which could result from implementation of the CoSWMP/General Plan Amendments' policies and programs are potentially significant from an environmental standpoint and may not be fully mitigated. The Board hereby directs the Community Development Department to address to following mitigation measures in the subsequent tiers of Environmental Impact Reports and other environmental documents implementing the California Environmental Quality Act that will emanate from the adoption of the 1989 County Solid Waste Management Plan and the five General Plan Amendments. If the project-level tier of environmental documents finds that the impacts are significant and that the particular mitigation measures are necessary to achieve substantial mitigation, the 45 Board declares its intent to adopt them as parts of the applicable projects or program approvals if the measures are subject to the control of the County. If the project-level tier of environmental documents also finds that the impacts are significant and unavoidable, the Board declares its intent to adopt a Statement of Overriding Considerations if the benefits of the project outweigh the unavoidable adverse impacts. Further, the monitoring program -- primarily an annual report on the implementation of the mitigation measures -- shall be carried out by the County Community Development Department. All other County departments and agencies involved in solid waste management shall assist with the preparation of the monitoring report. I. VEGETATION AND WILDLIFE 1. ImDact: Landfill development would result in the removal of wetlands and/or oak woodland vegetation (Marsh Canyon Sanitary Landfill, Keller Canyon Landfill, Kirker Pass Waste Management Landfill, East Contra Costa Sanitary Landfill, Bay Pointe Sanitary Landfill, and Acme Fill Expansion). a. Mitiqation: A wetland habitat enhancement plan would be proposed and ultimately implemented by the landfill developer. The plan would be developed in conjunction with and submitted to the appropriate resource management agencies for permit review, including the California Department of Fish and Game (DFG), the appropriate Regional Water Quality Control Board (RWQCB), United States Fish and Wildlife Service (USFWS), National Marine Fisheries Services (NMFS), and the U.S. Army Corps of Engineers (COE). At a minimum, the plan would provide for acre-for-acre and habitat unit-for-habitat-unit replacement for lost wetland. Oak woodland mitigation would be subject to the County's judgment. b. SuDDortinq Rationale: A habitat enhancement plan should be developed in conjunction with the County's consideration of a landfill applications and reviewed through its Environmental Impact Report. The habitat value of the on- or off-site mitigation area selected should be increased by means of sound management practices. It is noted that specific mitigation measures addressed in project-specific EIRs might reduce these impacts to less-than-significant levels. The County Community Development Department would ensure that a habitat enhancement and management plan would be implemented, when necessary, by incorporating it into the project's Land Use Permit Conditions of Approval. The plan, or variations of it, could also be implemented through regulatory agency permits. The 46 appropriate resource management agencies and the County Community Development Department shall oversee the implementation of the plan. c. Monitorin~ ProQrams~ The County Community Development Department shall submit an annual report to the Board on compliance to the provisions of this plan. II. GEOLOGY AND SOILS 1. Impact: Development/modification of a landfill would permanently alter the topography of the landfill site (all landfills). a. Mitiqation: A grading plan that is designed to blend the landfilled area with the surrounding topography would partially mitigate this impact. Contour grading techniques could provide a smooth transition between the new topography of the landfill and the natural topography of the site: cut and fills would be constructed with rounded corners to eliminate sharp angles of intersection; variable slope gradients would provide rounded, irregular forms that mimic natural slopes. Also, see the Visual Quality section following, and under Potentially Significant Impacts Fully Mitigated in this findings report. b. SuDDortinq Rationale: Significant topographic alteration will occur regardless of how well the landfilled area is blended into the surrounding land forms. The County Community Development Department would require that a proposed landfill project have an appropriate site grading program that is sensitive to the surrounding site area. It would be evaluated in the project's EIR and the resulting mitigation measures would be included in the Development and Improvements Plan of the Land Use Permit Conditions of Approval in order to ensure implementation. c. Monitorinq Proqram: The County Community Development Department shall report annually, if applicable, to the Board on the compliance of landfill developers to this requirement. III. VISUAL QUALITY 1. ImDact: Landfills sited in rolling hills would substantially change the existing visual contours (all 47 landfills). a. Mitiqation: To the extent practicable, landfill facilities should be sited well below the ridgeline levels, in canyons or valleys. The highest portion of the fill should be below surrounding ridgelines. Berms, fencing and/or landscaping should be employed to screen landfill operations. In addition, habitat enhancement and/or development to improve the visual character of the site could be implemented to help diminish visual impacts not fully mitigated by siting criteria. b. SuDDortinQ Rationale: Wherever a new landfill is sited, substantial visual alteration of the site would occur. This visual alteration can be diminished through the above proposed measures. It is noted that additional and/or more detailed measures identified in project-specific EIR's could reduce this impact to a less than significant level for a particular landfill. The County Community Development Department would ensure that mitigation measures identified in project EIRs to reduce the effect of this impact be implemented by incorporating them in the projects' Land Use Permit Conditions of approval. c. Monitorinq Proqram: The County Community Development Department shall report to the Board annually, as applicable, on compliance to the identified conditions. IV. CULTURAL RESOURCES 1. ImDact: Landfill operations could eliminate historic homesteads (Marsh Canyon Sanitary Landfill, East Contra Costa Sanitary Landfill). a. Mitiqation: A site survey for cultural resources should be considered by a qualified archaeologist before construct is begun. If evidence suggests that the site could yield additional information of importance to area history, the historic archaeologist should evaluate the resource and suggest mitigation measures, as part of the EIR, to compensate for the elimination of the cultural resource. b. SuDDortinq Rationale: The historic sites that would be eliminated if the two landfill projects were to proceed have had a survey and evaluation conducted, and mitigations recommended in the case of East Contra Costa Sanitary Landfill, and in the case of Marsh Canyon Sanitary Land~±11, a complete survey is being 48 l conducted for the impending EIR. The County Community Development Department will incorporate appropriate cultural resource mitigation measures identified in project EIRs into the Land Use Permit's Conditions of Approval. On-site mitigation measures shall be approved in conjunction with the Regional Clearinghouse of Sonoma State University, and a qualified archaeologist shall oversee their implementation. c. Monitorinq Proqram: The County Community Development Department shall report annually to the Board on the compliance of the landfill developer to the cultural resource conditions of approval. ALTERNATIVES The California Environmental Quality Act (CEQA) requires EIRs to describe a range of reasonable alternatives to the project, or to the location of the project, which could feasibly attain the basic objectives of the project and evaluate the comparative merits of the alternatives (CEQA Guidelines, Section 15126(d)). For the reasons stated below, these alternatives should be rejected in favor of the currently proposed plan. I. NO PROJECT ALTERNATIVE This alternative is defined as the failure to adopt a CoSWMP revision and General Plan Amendments, which would have the effect of maintaining the status quo with respect to solid waste management and landfill development in the County. In this alternative, no new landfills would be developed, existing landfills would be used until their closure, and then solid waste would be exported for disposal to other counties. With Acme Landfill's impending closure, waste currently going to Acme would be diverted to the two remaining landfills in the County. These two landfills, Contra Costa Sanitary Landfill (CCSL) and West Contra Costa Sanitary Landfill (WCCSL), are near capacity and at the present rate of waste acceptance are due to close in 1990-1991 and 1993, respectively. Although the CoSWMP identifies a 24-acre expansion at Acme Landfill, an application for such an expansion was denied by the Regional Water Quality Control Board in 1988. Expansion of CCSL and WCCSL are also provided for in the CoSWMP, if approvals can be obtained. If one or both are granted, they would provide only a few years of capacity for the County. In addition to new landfills, the CoSWMP includes policies for increasing the current rate of resource recovery. Failure to implement these provisions under the No Project Alternative would exacerbate the demands on the limited existing in-County capacity. After exhaustion of in-County capacity, the County would have to export its waste, which, though possibl~, 49 would not be a certainty, would be non-cost effective in the long run, and subject to other jurisdictions' requirements and politics. II. WASTE REDUCTION ALTERNATIVE The CoSWMP includes goals and policies for increasing the proportion of the County's solid waste that is diverted through resource recovery. The long-term goal is to divert 73 percent of the wastestream. In this alternative, three specific technologies would be used in lieu of landfilling solid waste, viz., recycling, composting, and waste-to-energy. Two in-depth County studies indicate that between 2 and 5 percent of the total wastestream could be reasonably reduced via residential recycling programs. Composting the approximately 10-15 percent vegetative waste of the residential wastestream would be equivalent to approximately 2 percent of the wastestream. Though waste-to- energy technologies could produce a 70-percent reduction by weight of the wastestream that is incinerated, there are several problems involved. Ash residue from mass incineration is about 30 percent by weight of incoming waste and this would have to be disposed of. Landfill disposal would still be required for this ash residue and for non-combustible material. In addition, waste-to-energy projects are capital intensive, the environmental issues are great, and the current chances for siting a project in the near term are slim. III. SUBSTITUTE LANDFILL SITES ALTERNATIVE During the years 1984-1987, there were three landfill siting studies performed in the County to identify potential sites. These efforts initially considered 22 sites, which were later narrowed through a ranking system to seven sites. Four of the final seven sites recommended to the Board of Supervisors are sites identified in the CoSWMP, the subject of these Findings. The reasons for dropping the other 15 sites are listed in Table 6.3-1 of the CoSWMP EIR, and deal mostly with the sites not meeting the County's list of criteria for new landfill development (Table 6.3-2 of the EIR). It was intended that developers of landfills would use this information to identify future sites in the County. During the first study, three sites were proposed by the private sector -- Kirker Pass Waste Management Landfill (KPWML), East Contra Costa Sanitary Landfill (ECCSL) and Central Landfill. The Central Landfill proposal was withdrawn in December of 1986. In 1987, KPWML and ECCSL completed their hearings and environmental review with the Planning Commission. Both were unable to obtain a majority approval by the Board of Supervisors. In 1988, the Marsh Canyon Sanitary Landfill and Keller Canyon Landfill were proposed by the private sector. They are currently undergoing environmental 50 review. This alternative was rejected because no sites other than those now proposed to be included in the CoSWMP are capable of becoming operating facilities by 1992 if site-specific studies were started now. However, none of the other sites have sponsors who have obtained control of the land and begun the application studies. IV. NO TRANSFER STATION ALTERNATIVE In this alternative, the CoSWMP revision and General Plan Amendments proposed project would not include the provision for transfer stations, and instead rely on direct haul of solid waste to landfill(s) and/or resource recovery facilities. This would entail the use of low-capacity packer trucks to haul the waste from the point of collection to the ultimate disposal or processing point, rather than using high-capacity transfer vehicles to haul waste from a transfer station to the ultimate disposal/processing location. There would be a substantially greater number of vehicle trips needed to transport a given amount of solid waste to its ultimate destination(s). In the worst case condition for traffic generation, a single landfill would become the destination for all the solid waste operations in the County. According to Table 6.3-3 in the CoSWMP/General Plan Amendment EIR, there would be almost three times as many vehicle trips generated under this scenario than under the proposed project scenario which includes transfer stations (1,726 trips by the year 2005 instead of 640 trips). There would be substantially greater air emissions and noise impacts. In addition, there could be more public service impacts due to road maintenance and traffic enforcement, and greater land use, visual and property value impacts as a result of increased traffic. CONCLUSION Incorporating mitigation measures and rejecting the proposed alternatives in the Final Environmental Impact Report, as stated in these findings, into the CEQA Project (County Solid Waste Management Plan/General Plan Amendments) reduces environmental impacts that would result from this Project to less-than- significant levels, and through adoption of the Statement of Overriding Considerations set forth hereunder, the requirements of the California Environmental Quality Act have been satisfied with regard to the proposed CoSWMP Revision.' STATEMENT OF OVERRIDING CONSIDERATIONS Notwithstanding the disclosure of the significant impacts and the 51 3 mitigation measures described above, pursuant to Section 15093 of the State CEQA Guidelines, the benefits of the Project outweigh the unavoidable significant adverse environmental impacts, and the Project should be approved. There are special social, economic and other reasons for approving this project, notwithstanding the disclosure of substantial adverse impacts disclosed in the Final Environmental Impact Report and described above as significant impacts not fully mitigated. The reasons are as follows: 1. Vegetation and Wildlife: To the extent that the EIR for the CoSWMP/General Plan Amendments finds that there remains a not-fully mitigated environmental impact due to the removal of wetlands and/or oak woodland vegetation at the proposed landfill sites and the proposed Acme Fill Expansion, such impact is justified by the need to locate a new landfill and/or expand an existing landfill in the County to increase landfill capacity before the existing capacity is exhausted, in order to forestall a public health hazard and accommodate the County's growing population and employment base. Furthermore, the existing project-specific EIRs for three of the landfill sites (Kirker Pass Waste Sanitary Landfill, East Contra Costa Sanitary Landfill, Acme Landfill) have identified habitat enhancement mitigation measures to compensate for the loss of these habitats; proposals for the remaining two sites (Marsh Canyon Sanitary Landfill, Bay Pointe Sanitary Landfill) would be required to prepare and implement habitat enhancement plans. These plans would be made conditions of approval for these projects. 2. Geology and Soils: To the extent that the EIR for the CoSWMP/General Plan Amendments finds that there remains a not-fully mitigated environmental impact due to the permanent alteration of the topography to all sites identified in the Project, such impact is justified by the need to locate a new landfill and/or expand an existing landfill in the County to increase landfill capacity before the existing capacity is exhausted, in order to forestall a public health hazard and accommodate the County's growing population and employment base. 3. Visual Quality: To the extent that the EIR for the CoSWMP/General Plan Amendments finds that there remains a not-fully mitigated environmental impact due to the adverse and dramatic change in the existing visual character of the landfill sites identified in the Project, such impact is justified by the need to locate a new landfill and/or expand an existing landfill in the County to increase landfill capacity before the existing capacity if exhausted, in order to forestall a public health hazard and accommodate the County's growing population and employment base. Furthormorot tho c~ioCing projoGt-opeGif±c ~IRD for three of 52 the landfill sites (Kirker Pass Waste Management Landfill, East Contra Costa Sanitary Landfill and Acme Landfill) have identified screening and habitat enhancement mitigation measures which would substantially reduce the visual impacts of the installation of these facilities. 4. Cultural Resources: To the extent that the EIR for the CoSWMP/General Plan Amendments finds that there remains a not-fully mitigated environmental impact due to the elimination of historic homesteads on two of the sites identified in the Project (East Contra Costa Sanitary Landfill, Marsh Canyon Sanitary Landfill), such impact is justified by the need to locate a new landfill and/or expand an existing landfill in the County to increase landfill capacity before the existing capacity is exhausted, in order to forestall a public health hazard and accommodate the County's growing population and employment base. Furthermore, the existing project EIR for East Contra Costa Sanitary Landfill has identified mitigation measures for the homestead elimination impact. The homestead located in the site of the proposed Marsh Canyon Sanitary Landfill is being addressed in the impending project EIR. 53