Appendices_TT_Agency_Review_Draft_OU-1_FS-February_2006.pdf

APPENDIX A

Applicable or Relevant and Appropriate Requirements

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APPLICABLE OR RELEVANT AND APPROPRIATE REQUIREMENTS

This appendix identifies and evaluates potential federal and State of California applicable or relevant and appropriate requirements (ARAR) and sets forth EPA’s determinations regarding those potential ARARs for each response action alternative retained for detailed analysis in the Sulphur Bank Mercury Mine

(SBMM) superfund site feasibility study (FS). Section A.1 summarizes the definitions and concepts pertinent to ARAR determinations. The three categories of ARARs, chemical-, location- and action-specific, are described in Sections A.2, A.3, and A.4, respectively. The Section A.4 discussion of action specific ARARs also provides an analysis of the exemption of mining wastes from regulation as a hazardous waste under Section 3001(b)(3)(A)(ii) of the Resource Conservation and Recovery Act (also known as the Bevill Amendment) and under the California Health and Safety Code, Section

25143.1(b)(1) and (2).

EPA has primary responsibility for identifying federal ARARs at Sulphur Bank Mercury Mine (SBMM).

On February 17, 1993, EPA received a memorandum identifying potential state ARARs from the

California Regional Water Quality Control Board – Central Valley Region. EPA has identified the following federal and state ARARs for the SBMM.

A.1 SUMMARY OF CERCLA AND NCP REQUIREMENTS

Section 121(d) of the Comprehensive Environmental Response, Compensation, and Liability Act of 1980

(CERCLA), as amended, 42 U.S.C. § 9621(d), states that remedial actions on CERCLA sites must attain

(or the decision document must justify the waiver of ) any federal or more stringent state environmental standards, requirements, criteria, or limitations that are determined to be legally applicable or relevant and appropriate.

Applicable requirements are those cleanup standards, standards of control, and other substantive environmental protection requirements, criteria, or limitations promulgated under federal or state law that specifically address the situation at a CERCLA site. The requirement is applicable if the jurisdictional prerequisites of the law or regulation directly address the circumstances at the site. An applicable federal requirement is an ARAR. An applicable state requirement is an ARAR only if it is more stringent than federal ARARs.

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If the requirement is not legally applicable, then the requirement is evaluated to determine whether it is relevant and appropriate. Relevant and appropriate requirements are those cleanup standards, standards of control, and other substantive environmental protection requirements, criteria, or limitations promulgated under federal or state law that, while not applicable, address problems or situations similar to the circumstances of the proposed response action and are well suited to the conditions of the site (U.S.

EPA 1988a). A requirement must be determined to be both relevant and appropriate to be considered an

ARAR.

The criteria for determining relevance and appropriateness, as listed in 40 C.F.R. § 300.400(g)(2), are:

• the purpose of the requirement and the purpose of the CERCLA action;

• the medium regulated or affected by the requirement and the medium contaminated or affected at the CERCLA site;

• the substances regulated by the requirement and the substances found at the CERCLA site;

• any variances, waivers, or exemptions of the requirement and their availability for the circumstances at the CERCLA site;

• the type of place regulated and the type of place affected by the release or CERCLA action;

• the type and size of structure or facility regulated and the type and size of structure or facility affected by the release or contemplated by the CERCLA action; and

• any consideration of use or potential use of affected resources in the requirement and the use or potential use of the affected resources at the CERCLA site.

A requirement may be “applicable” or “relevant and appropriate,” but not both. Identification of ARARs is done on a site-specific basis and involves a two-part analysis: first, a determination whether a given requirement is applicable; then, if it is not applicable, a determination whether it is nevertheless both relevant and appropriate. When the analysis determines that a requirement is both relevant and appropriate, such a requirement must be complied with to the same degree as if it were applicable (U.S.

EPA 1988b).

To qualify as a state ARAR under CERCLA and the National Oil and Hazardous Substances Pollution

Contingency Plan (NCP), a state requirement must be:

• a state law,

• an environmental or facility siting law,

• promulgated (of general applicability and legally enforceable),

• substantive (not procedural or administrative), A-3

• more stringent than the federal requirement,

• identified in a timely manner, and

• consistently applied.

To constitute an ARAR, a requirement must be substantive. Therefore, only the substantive provisions of requirements identified as ARARs in this analysis are considered to be ARARs. Permits are considered to be procedural or administrative requirements. Provisions of generally relevant federal and state statutes and regulations that were determined to be procedural or nonenvironmental, including permit requirements, are not considered to be ARARs.

Nonpromulgated advisories or guidance issued by federal or state governments are not legally binding and do not have the status of ARARs. Such requirements may, however, be useful, and are “to be considered” (TBC). As outlined in 40 C.F.R. § 300.400(g)(3), TBC requirements complement ARARs but do not override the ARARs. They are useful for guiding decisions regarding cleanup levels or methodologies when regulatory standards are not available.

Additional general information regarding ARARs may be found in EPA's CERCLA Compliance with

Other Laws Manual (August 1989) (two volumes). Specific ARARs issues are also discussed in the

March 8, 1990, Federal Register notice publishing the final rule for the National Contingency Plan. See

55 Fed. Reg. 8666, et seq.

EPA has developed three categories of ARARs to assist in the identification of ARARs. The three categories are (1) chemical-specific, (2) location-specific, (3) and action-specific ARARs. EPA guidance recognizes that some requirements do not fall neatly into this classification. These categories are described in the following sections.

A.2 CHEMICAL SPECIFIC ARARS AND TBCS

Chemical-specific ARARs are generally health- or risk-based numerical values or methodologies applied to site-specific conditions that result in the establishment of a cleanup level. The three media of concern at the Sulphur Bank Mercury Mine OU1 are:

• groundwater

• surface water

• ore piles/tailings/waste rock piles

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Potential ARARs for these media are evaluated below.

A.2.1 Groundwater ARARs and TBCs

The identification of ARARs for groundwater depends on whether the groundwater is a potential drinking water source. Under the U.S. EPA’s Guidelines for Groundwater Classification, groundwater is considered a potential drinking water source unless the there is insufficient quality (total dissolved solids

(TDS) concentrations are over 10,000 mg/L) or quantity (yield is less than 150 gallons per day). Under the State of California’s Sources of Drinking Water Policy, State Water Resources Control Board

(SWRCB) Resolution No. 88-63, groundwater is considered a potential drinking water source if the TDS levels are below 3,000 milligrams per liter (mg/L) and the individual well yield is more than 200 gallons per day.

The average TDS of the regional groundwater east and north of Herman Impoundment (including groundwater affected by the hydrothermal system) is above 3,000 mg/L. The average yield of wells completed in the regional (Franciscan or Andesite) aquifer is below the 150 gallons per day U.S. EPA criteria. Thus, using these guidelines, regional groundwater at the site is not considered a potential drinking water source. Accordingly, drinking water standards have not been identified as potential

ARARs.

No federal groundwater ARARs have been identified. The following regulations are potential state

ARARs for groundwater underlying the site:

• Central Valley Regional Water Quality Control Board (RWQCB) Basin Plan water quality objectives

• SWRCB Resolution 68-16, Statement of Policy With Respect to Maintaining High Quality

Waters in California

• SWRCB Resolution 92-49IIIG, Policies and Procedures for Investigation and Cleanup and

Abatement of Discharges under California Water Code Section 13304

Each of these potential ARARs is discussed below.

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A.2.1.1 Central Valley Water Quality Control Plan (Basin Plan):

The Basin Plan for the Central Valley was prepared and implemented by the Central Valley RWQCB to protect and enhance the quality of waters in the region. The Basin Plan establishes location-specific beneficial uses and water quality objectives (WQOs) for surface water and groundwater of the region.

The Basin Plan includes both numeric and narrative WQOs. The WQOs are intended to protect the beneficial uses of the water of the region and to prevent nuisance.

The Basin Plan contains the following pertinent narrative WQOs for groundwater:

• Chemical Constituents: “Groundwater shall not contain chemical constituents in concentrations that adversely affect beneficial uses.”

• Toxics: “Groundwater shall be maintained free of toxic substances in concentrations that produce detrimental physiological responses in human, plant, animal, or aquatic life associated with designated beneficial uses.”

A.2.1.2 SWRCB Resolution 68-16

Resolution 68-16, Statement of Policy With Respect to Maintaining High Quality Waters in California, establishes the policy that high quality waters of the state “shall be maintained to the maximum extent possible” consistent with the “maximum benefit to the people of the state.” It requires the maintenance of high quality waters until it has been demonstrated that any change will be consistent with maximum benefit to the people of the state, will not unreasonably affect beneficial uses of such water, and will comply with applicable water quality control policies. It further requires that any discharge of waste to high quality waters comply with requirements resulting in best practicable treatment or control to prevent pollution or nuisance.

A.2.1.3 SWRCB Resolution 92-49

SWRCB Resolution 92-49 contains policies and procedures that the regional boards apply to all investigations and cleanup and abatement activities for all types of discharges subject to Water Code

Section 13304. Section III.G of the Resolution requires attainment of background water quality, or if background cannot be restored, the best water quality that is reasonable.

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A.2.2 Surface Water ARARs

As with groundwater, the identification of surface water ARARs also hinges on the beneficial uses of the water. In the Basin Plan, the existing beneficial uses for Clear Lake are municipal domestic supply, agriculture, recreation, warm freshwater habitat, spawning, and wildlife habitat. Potential federal surface water ARARs are the Safe Drinking Water Act and the Clean Water Act water quality standards for priority toxic pollutants for California inland surface waters. Potential state ARARs are the State of

California MCLs, the Basin Plan, and Resolutions 68-16 and 92-49.

A.2.2.1 Federal Surface Water ARARs

Potential federal surface water ARARs are discussed below.

A.2.2.1.1 Safe Drinking Water Act

The SDWA, 42 U.S.C. § 300(f) et seq., sets limits on the concentrations of certain hazardous materials in drinking water. Maximum contaminant levels (MCLs) are applied at the tap to water that is delivered directly to 25 or more people or to 15 or more service connections. Under the SDWA, EPA has also designated Maximum Contaminant Level Goals (MCLGs), which are health-based goals, generally more stringent than MCLs. CERCLA Section 121(d)(2)(A)(i) provides that CERCLA response actions “shall require a level of standard or control which at least attains Maximum Contaminant Level Goals established under the Safe Drinking Water Act.” 42 U.S.C. § 9621(d)(2)(A)(i). Section

300.430(e)(2)(i)(B) of the NCP provides that remedial actions must generally attain MCLs or non-zero

MCLGs if water is a current or potential source of drinking water. 40 C.F.R. § 300.430(e)(2)(i)(B).

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EPA has adopted MCLs (40 C.F.R. § 141.62(b)) or MCLGs (40 C.F.R. § 141.51) for the following hazardous substances detected in surface water at SBMM:

US EPA Maximum Contaminant Levels

Substance MCL MCLG Antimony 0.006 mg/L 0.006 mg/L Arsenic 0.01 mg/L None Chromium (total) 0.100 mg/L 0.100 mg/L Mercury (inorganic) 0.002 mg/L 0.002 mg/L Nickel None None Zinc None 5.0 mg/L (secondary MCL)

A.2.2.1.2 Federal Water Quality Criteria, EPA California Toxics Rule

On December 22, 1992, EPA promulgated federal water quality standards under the authority of CWA

Section 303(c)(2)(B) to establish water quality standards where the State of California had failed to do so.

Priority toxic pollutants for California inland surface waters are contained in 40 C.F.R. § 131.38. Criteria for the toxic priority pollutants found at SBMM are shown in the following table.

US EPA California Toxics Rule Water Quality Criteria for Inland Surface Waters

Substance Freshwater Human Health

Maximum Concentration (1-hour Average) (�g/l)

Continuous Concentration (4-day Average) (�g/l)

Consumption of water and organisms (�g/l)

Consumption of organisms (�g/l)

Antimony NA NA 142 4,3002

Arsenic 3401 1501 NA NA

Chromium III 550*1

1,700*2 180*1

210*2

NA NA

Chromium VI 161 111 NA NA

Mercury NA NA 0.052 0.0512

Nickel 470*1,2 52*1,2 6102 4,6002

Zinc 120*1,2 120*1,2 NA NA

Notes:

µg/l = micrograms per liter NA = Not available

* = Concentration is hardness dependant, the given value is for hardness of 100 mg/L 1 = Dissolved concentrations 2 = Total Recoverable Concentrations

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A.2.2.2 State Surface Water ARARs and TBCs

Potential state surface water ARARs are discussed below.

A.2.2.2.1 State Safe Drinking Water Act

The state of California has adopted primary and secondary MCLs for public drinking water under the

California Safe Drinking Water Act of 1976. Some state MCLs may be more stringent than the corresponding federal MCL, in which case the state MCL would generally be the ARAR. The MCLs are set forth in Title 22 California Code of Regulations §§ 64431 and 64449(a). The MCLs for the chemicals of concern in groundwater at the site are listed in the following table.

California Maximum Contaminant Levels

Substance Primary MCL Secondary MCL Antimony 0.006 mg/L None Arsenic 0.05 mg/L None Chromium (total) 0.05 mg/L None Mercury (inorganic) 0.002 mg/L None Nickel 0.100 mg/L None Zinc None 5.0 mg/L

A.2.2.2 Central Valley Regional Water Quality Control Board Basin Plan

The Basin Plan identifies MCLs as the standard for surface water drinking water sources. The Basin Plan also includes narrative WQOs for surface water within the region. The WQOs potentially pertinent to the remedial action at SBMM are as follows:

• Suspended material: Waters shall not contain suspended material in concentrations that cause nuisance or adversely affect beneficial uses.

• Toxics: Water shall be maintained free of toxic substances in concentrations that produce detrimental physiological responses in human, plant, animal, or aquatic life

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A.2.3 Ore Piles, Tailings, Waste Rock Pile ARARs and TBCs

The EPA has reviewed federal and state requirements and determined that there are no chemical-specific

ARARs for the ore piles, tailings, and waste rock piles at the SBMM site. Site specific human health and ecological risk assessments have been performed that identify soil cleanup goals that are protective for human health and the environment under expected future land use scenarios. Site specific information on the bioavailability of mercury in soils was used to identify the soil cleanup goal for exposures to mercury under the expected future land use. The soil cleanup goals for soils containing arsenic and antimony were derived from the Region 9 preliminary remediation goals (PRG) and expected exposure scenarios under the expected future land use. These risk assessment derived goals are used in lieu of EPA Region 9 PRGs for mercury. Although the Region 9 PRGs are risk based, the Region 9 PRGs are not based on site specific factors and do not consider the expected future land use or exposures to multiple chemicals or multiple exposure pathways.

A.3 Location-Specific ARARs and TBCs

Location-specific ARARs are restrictions on the concentrations of hazardous substances on the conduct of activities solely because they are in specific locations. Special locations include floodplains, wetlands, historic places, and sensitive ecosystems or habitats. The Archeological Resources Protection Act, Native

American Graves Protection and Repatriation Act, American Indian Religious Freedom Act, the Fish &

Wildlife Coordination Act, and various California natural resource laws are some of the potential ARARs.

Location-specific ARARs are summarized below.

A.3.1 Federal Location-Specific ARARs

Potential federal location specific ARARs are discussed below.

A.3.1.1 Archeological Resources Protection Act

The Archeological Resources Protection Act, 16 U.S.C. §§ 470aa et seq., protects archeological resources from unauthorized excavation, removal, damage or alteration.

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A.3.1.2 Native American Graves Protection and Repatriation Act

The Native American Graves Protection and Repatriation Act (NAGPRA), 25 U.S.C. §§ 3001 et seq. and its regulations, 43 C.F.R. Part 10, protect Native American graves from desecration through the removal and trafficking of human remains and cultural items including funerary and sacred objects. To protect

Native American burials and cultural items, the regulations require that if such items are inadvertently discovered during excavation, the excavation must cease and the affiliated tribes must be notified and consulted. This program is potentially applicable to ground-disturbing activities such as soil grading and removal. If a possible grave site is discovered in the course of soil disturbances, work will be stopped and the Elem Tribe will be contacted.

A3.1.3 American Indian Religious Freedom Act

The American Indian Religious Freedom Act, 42 U.S.C. §§ 1996 et seq. is potentially applicable to soil excavation at the SBMM. It protects religious, ceremonial, and burial sites and the free practice of religions by Native American groups. If sacred sites are discovered in the course of soil disturbances, work will be stopped and the Elem Tribe will be contacted.

A.3.1.4 National Historic Preservation Act

The National Historic Preservation Act (NHPA), 16 USC § 470 et seq., requires federal agencies to take into account the effect of any federally assisted undertaking or licensing on any district, site, building, structure, or object that is included in or eligible for inclusion in the National Register of Historic Places

(NRHP). If an eligible structure were encountered, the procedures for protection of historic properties set forth in 36 CFR Part 800 are potentially applicable.

A.3.1.5 Endangered Species Act

The Endangered Species Act (ESA), 16 USC §1531, et seq., requires consultation with the resource agencies for remedial actions that may affect these species. Section 7 of the ESA requires that federal agencies consider whether their actions will jeopardize the existence of species that are listed as threatened or endangered by the U.S. Fish and Wildlife Service (USFWS) or the National Marine

Fisheries Service (NMFS). If the proposed action may affect the listed species or its critical habitat, A-11 consultation with the USFWS may be required (50 C.F.R. § 402.14). Additionally, Section 9 of the ESA prohibits the illegal taking of a listed species (16 U.S.C. § 1538(a)(1).

A.3.1.6 Fish and Wildlife Coordination Act

The Fish and Wildlife Coordination Act, 16 U.S.C. §§ 661 et seq., was enacted to protect fish and wildlife when federal actions result in the control or structural modification of a natural stream or body of water.

The statute requires federal agencies to take into consideration the effect that water-related projects would have upon fish and wildlife and then take action to prevent loss or damage to these resources.

A.3.1.7 Migratory Bird Treaty Act

The Act, 16 U.S.C. §§ 703 et seq., establishes federal responsibility for the protection of migratory bird resources. It prohibits at any time, using any means or manner, the pursuit, hunting, capturing, killing or attempting to take, capture, or kill any listed migratory bird, except under the terms of a valid permit issued pursuant to Federal regulations.

A.3.1.8 Floodplain and Wetland Protection

The Executive Order on Floodplain Management, Executive Order No. 11,988, requires that federal agencies evaluate the potential effects of actions that may take place in a floodplain to avoid, to the extent possible, adverse effects associated with direct and indirect development of a floodplain. The Executive

Order on Protection of Wetlands, Executive Order No. 11,990, requires that federal agencies avoid, to the extent possible, adverse impacts associated with the destruction or loss of wetlands and to avoid support of new construction in wetlands, if a practicable alternative exists. EPA's regulations to implement these

Executive Orders are set forth in 40 CFR §6.302(b). In addition, EPA has developed guidance entitled

Policy on Floodplains and Wetlands Assessments for CERCLA Actions, dated August 6, 1985 (EPA, 1985b). The requirements of this regulation are potentially applicable if any remedial activities affect a floodplain or impact existing wetlands at the site.

A.3.2 California Location-Specific ARARs

Potential state location-specific ARARs are discussed below.

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A.3.2.1 California Endangered Species Act

California Department of Fish & Game Code Section 2080 prohibits the illegal taking of plant and animal species designated as either threatened or endangered in the state of California.

A.3.2.2 California Wildlife Statutes

California Department of Fish & Game Code Section 5650 makes it unlawful to “deposit in, permit to pass into, or place where it can pass into the waters of the state . . . [a]ny substance or material deleterious to fish, plant life, or bird life.”

A.3.2.3 Streambed Alteration Agreement

California Fish and Game Code § 1602 prohibits alteration of streambeds or impeding natural flow in streambeds absent an agreement with the California Department of Fish and Game.

A.4 ACTION-SPECIFIC ARARS AND TBCS

Action-specific ARARs are technology- or activity-based requirements or limitations on actions taken with respect to hazardous substances. These requirements are triggered by the particular remedial activities selected. This section summarizes the general action-specific ARARs for the alternatives. A discussion of the action-specific ARARs as they apply to each alternative is included in Section 7.0, as part of the detailed analysis of the alternatives.

For alternatives that involve the excavation/extraction, treatment and/or disposal of contaminated media, the following regulations were evaluated as ARARs.

A.4.1 Federal Action-Specific ARARs

Potential federal action specific ARARs are discussed below.

A.4.1.1 Federal Mining Waste Regulations

Under the Resource Conservation and Recovery Action (RCRA) Section 3001(b)(3)(A)(ii), 42 U.S.C.

6921(b)(3)(A)(ii) (also known as the "Bevill amendment"), Congress exempted most mining wastes that

A-13 are the result of mineral extraction or beneficiation, or are residues from treatment of such wastes from regulation as hazardous waste. Exempted waste includes waste from the extraction and beneficiation of minerals, and some mineral processing wastes. See 40 C.F.R. §261.4(b)(7).

Under the Bevill exclusion, many solid wastes that would otherwise be characteristically hazardous would not qualify as hazardous wastes. The Bevill exclusion, codified at 40 C.F.R. Part 261.4(b)(7), provides that "[s]olid waste from the extraction, beneficiation, and processing of ores and minerals (including coal, phosphate rock, and overburden from the mining of uranium ore) [are not hazardous wastes]”.

The waste sources and potential waste sources in OU-1 of SBMM are:

• Herman Impoundment System, including the Waste Rock Dam, the Satellite Waste Rock Pile, and associated surface water and groundwater

• Northwest Pit System, including the pit and associated surface and groundwater

• Ore Piles System, including the East and West Ore Piles and associated surface water, groundwater and acid rock drainage (ARD)

• Tailings System, including the Tailings Pile and associated surface water, groundwater and

ARD

• Waste Rock System, including the Northwest, North, South and West Waste Rock Piles and associated surface water, groundwater, and ARD

• Disturbed Rock System, including an area of disturbed native rock north of the Herman

Impoundment and associated surface and groundwater

• Native Rock System, including areas of undisturbed native rock within the boundaries of OU

1 and associated surface and groundwater

Although treatment residues from treating ARD are residues of extraction or beneficiation wastes and therefore subject to the Bevill exemption, they would also be exempt under the criteria EPA uses to determine which residues of processing wastes would be excluded. EPA explained in the preamble to the final mining waste exclusion rule for processing wastes that Bevill-excluded waste "should include pollution control residuals that meet the high volume and low hazard criteria required for excluded wastes." 54 Fed. Reg. 36592, 36621 (September 1, 1989). EPA determines low hazard in one of two ways: (1) a pH test and (2) a mobility and toxicity test. The pH test requires that the residue have a pH of between 1 and 13.5 to be exempt. The mobility and toxicity test requires that mineral processing waste constituents be extracted from the waste using Method 1312, the Synthetic Precipitation Leaching

Procedure ("SPLP"), and the extract is to be evaluated in the same manner and against the same regulatory level as in the extraction procedure. Using these criteria and taking into consideration

A-14 available data, it appears likely that water treatment sludge would qualify as high volume, low toxicity wastes.

By letter dated March 30, 1992, the California Department of Toxic Substances Control (DTSC) and the

Regional Board questioned whether the Bevill amendment applies to mining waste such as acid mine drainage (AMD). Upon reexamination of this issue, EPA has confirmed that the Bevill amendment does apply to AMD, including the AMD at SBMM. Among other matters considered, EPA reviewed the

December 1985 EPA "Report to Congress: Wastes from the Extraction and Beneficiation of Metallic

Ores, Phosphate Rock, Asbestos, Overburden from Uranium Mining, and Oil Shale," prepared by EPA pursuant to the Bevill amendment. This study clearly identifies mine waste waters, including AMD, within the scope of extraction wastes subject to the amendment. The Report specifically considered

SBMM and its AMD problem in its review of the environmental problems caused by extraction wastes.

Although Bevill wastes are not hazardous wastes, EPA has determined that they are solid wastes, as defined in 40 C.F.R. § 261.2 (54 FR 36614, September 1, 1989) and thus are subject to Subtitle D requirements, 40 C.F.R. Part 257, Subpart A. These regulations are primarily siting requirements that limit the disposal of solid waste in certain locations. These regulations are potentially applicable to management and disposal of material generated by cleanup activity. The regulations require that facilities in floodplains not restrict the flow of the base flood, not reduce the temporary water storage capacity of the floodplain, not result in washout of solid waste; and not cause or contribute to the taking of any endangered or threatened species. Facilities must not cause a discharge of pollutants into waters of the

U.S. that violates the requirements of the National Pollution Discharge Elimination System (NPDES) program and must not contaminate an underground drinking water source beyond the solid waste boundary.

A.4.1.2 Resource Conservation and Recovery Act

Subtitle C of the Resource Conservation and Recovery Act, 42 U.S.C. §§ 6901 et seq., governs treatment, storage and disposal of non-Bevill exempt hazardous wastes outside of the area of contamination. See also 40 C.F.R. parts 260-268. In addition, the following RCRA requirements may be relevant and appropriate to onsite management of Bevill-exempt mining wastes that exhibit hazardous waste characteristics, to the extent that requirements provide a greater level of protection to human health than requirements applicable to mining waste.

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• 40 CFR Part 261, Hazardous Waste Identification (substantive provisions). Establishes criteria for identifying a hazardous waste that is subject to RCRA Subtitle C regulation. Hazardous waste management requirements may be relevant and appropriate to mining wastes that exhibit hazardous waste characteristics.

• 40 CFR Part 264 Subpart B, General Facility Standards (substantive provisions). Establishes general requirements for hazardous waste treatment, storage or disposal (TSD) facilities, including the requirement to be located at least 200 feet from a Holocene fault, and requirements to prevent washout if located within a 100 year floodplain.

• 40 CFR Part 264, Subpart C, Preparedness and Prevention (substantive provisions). Establishes requirements for preventing and responding to a release or other emergency, including requirements to have specified communication and emergency response equipment onsite in the waste management areas.

• 40 CFR Part 264 Subpart F, Releases from Solid Waste Management Units (substantive provisions). Establishes requirements for groundwater monitoring at land-based hazardous waste disposal units, including establishing a groundwater protection standard, and taking specified corrective actions if the groundwater protection standard is exceeded at the downgradient point of compliance.

• 40 CFR Part 264 Subpart G, Closure and Post-Closure (substantive provisions). Establishes general requirements for closure of hazardous waste management units, including the general performance standard that: they be closed in a manner that minimizes the need for further maintenance; and controls, minimizes or eliminates post-closure escape of hazardous waste.

• 40 CFR Part 264 Subpart J, Tank Systems (substantive provisions). Establishes requirements for hazardous waste treatment and storage tank systems, including the requirement for tanks and appurtenances to have secondary containment.

• 40 CFR Part 264 Subpart L, Waste Piles (substantive provisions). Establishes requirements for hazardous waste piles, including the requirement to remove all waste and contaminated soil at closure, or close the pile as a landfill.

• 40 CFR Part 264 Subpart N, Landfills (substantive provisions). Establishes requirements for hazardous waste landfills, including the requirements to have a double liner and leachate collection system meeting specified standards, and to close the landfill using a cap meeting specified standards that has a permeability no greater than the permeability of the liner.

• 40 CFR Part 264 Subpart S, Special Provisions for Cleanup (substantive provisions). Establishes technical standards for Corrective Action Management Units for onsite placement of remediation waste that provide more site-specific flexibility and are potentially less stringent than the requirements for hazardous waste landfills and waste piles.

A.4.1.3 Clean Water Act, NPDES Permit Requirements

The Clean Water Act, 33 U.S.C. §§ 1251 et seq. contains permit requirements for discharges to waters of the United States. Id § 1342. For those alternatives that would involve discharge to surface water, the substantive requirements of 40 C.F.R. Part 122 are potential ARARs for onsite discharges to surface water. An NPDES permit would be required for offsite discharges to surface waters

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A.4.1.4 Clean Water Act Effluent Limitations

There are no effluent limitations specifically identified for inactive mercury mines. There are limitations for active mercury mines, which are found at 40 C.F.R. §§ 440.40- 440.45. Because the problems of acid mine drainage from SBMM are similar to the problems of active mercury mines, EPA has identified the effluent limitations as potentially relevant and appropriate. The Clean Water Act established effluent limitations according to whether the discharge is from a new or existing source and whether the pollutant is conventional, toxic, or a non-conventional, non-toxic pollutant. Existing sources were initially required to achieve best practicable control technology (BPT) and later best available technology economically achievable (BAT). The BPT and BAT limits at mercury mines are as follows:

US EPA Effluent Limitations for Active Mercury Mines

Effluent Limitations Effluent Characteristic Maximum for any 1 Day

(mg/L) Avg. daily values/30 days

(mg/L)

Total Suspended Solids 30 20

Mercury 0.002 0.001

Nickel 0.2 0.1 pH Within the range of 6.0 to 9.0 Within the range of 6.0 to 9.0

A.4.1.5 Clean Water Act, Section 404

Section 404 of the Clean Water Act, 33 U.S.C. §§ 1251 et seq., regulates the discharge of dredged or fill material into waters of the United States, including wetlands. 33 U.S.C. § 1344. Regulations implementing the permitting requirements are found in 40 C.F.R. Part 230. One of the guiding principles is to avoid degradation and destruction of wetlands to the extent possible.

A.4.1.6 Section 10 of the Rivers and Harbors Act

Section 10 of the Rivers and Harbors Act, 33 U.S.C. § 403, prohibits the unauthorized obstruction or alteration of any navigable water of the United States. Structures or work in, above, or under navigable waters are regulated under Section 10. The substantive permit requirements are contained in 33 C.F.R.

Parts 320-322. These regulations require an examination into the impact on the public interest of the proposed activity. Section 10 of the Rivers and Harbors Act is potentially applicable if dredge and fill activities occur in Clear Lake.

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A.4.1.7 Clean Water Act, NPDES Permit Requirements for Stormwater Discharges

Any on-site discharge of stormwater runoff associated with construction of the proposed remedy must meet the substantive requirements of the General NPDES Permit for Stormwater Discharges Associated with Construction Activity, Order No. 99-08-DWQ, issued by the SWRCB pursuant to is delegated authority under the Clean Water Act. In addition, the substantive requirements of the General Permit for

Stormwater Discharges associated with Industrial Activities, Order No. 97-03-DWQ, may be potential

ARARs because inactive mines are considered to be an industrial activity for purposes of the permit.

A.4.1.8 Surface Mining Control and Reclamation

The Surface Mining Control and Reclamation Act (SMCRA), 30 U.S.C. §§ 1201 et seq., establishes a nationwide program for the protection of human health and the environment from the adverse effect of surface coal mining operations. Although SMCRA addressed abandoned coal mines, it may be relevant and appropriate to cleanup of other types of mining sites. In its CERCLA Compliance with Other Laws

Manual, EPA explained that SMCRA may be relevant and appropriate at (1) sites with sulfide-containing geologic materials and there is a release or threat of release of acid and at (2) sites subject to erosion and thus releases are contaminated by heavy metals. The following regulations, which provide guidelines for post-mining rehabilitation and reclamation of surface mines (Part 816) and underground mines (Part 817) may be potentially relevant and appropriate:

• 30 C.F.R. §§ 816.43/817.43 – standard for diversions of flow from disturbed areas

• 30 C.F.R. §§ 816.56/817.56 – post mining rehabilitation of sedimentation ponds, diversions, impoundments

• 30 C.F.R. §§ 816.97/817.97 – protection of fish and wildlife

• 30 C.F.R. §§ 816.111/817.11, 816.114/817.114, and 816.116/817.116 – revegetation requirements

• 30 C.F.R. §§ 816.132/817.132 – standards for cessation of operations

A.4.2 State Action-Specific ARARs

Potential state action specific ARARs are discussed below.

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A.4.2.1 California Mining Waste Regulations (California Water Code)

Pursuant to Water Code Section 13172, the state of California has adopted regulations designed to address the management of mining waste. These regulations are found at 27 CCR §§ 22470-22510. The regulations establish three groups of mining waste:

• Group A – mining waste that the must be managed as hazardous waste provided the RWQCB finds that such mining wastes pose a significant threat to water quality

• Group B – mining wastes that consist of or contain hazardous wastes that qualify for a variance, provided that the RWQCB finds that such mining wastes pose a low risk to water quality, or mining wastes that consist of or contain nonhazardous soluble pollutants of concentrations which exceed water quality objectives for, or could cause, degradation of waters of the state

• Group C – wastes from which any discharge would be in compliance with the applicable water quality control plan, include water quality objectives other than turbidity

Classification of the mining waste as hazardous under the Hazardous Waste Control Act is used to determine which group designation is appropriate. The mining wastes from SBMM are appropriately classified as Group A wastes. The regulations contain specific requirements on siting, construction, monitoring, and closure and post-closure maintenance of existing and new units. These requirements are ARARs for alternatives that involve the creation of an on-site disposal unit or closure of existing units.

Design and Siting under Water Code Section 13172

Under State regulations governing the design of mining waste disposal units, the Regional Board imposes specific requirements on siting, construction, monitoring, and closure and post-closure maintenance of existing and new Group A disposal units. The requirements for new Group A Units are :

• Shall not be located on Holocene faults

• Shall be outside areas of rapid geologic change, but may be located there if containment structures are designed and constructed to preclude failure

• Flood protection—locate outside of 100-year flood plain

• Construction standards--for waste piles, the pile must be underlain with a single clay liner (at least 1 x 10-7 permeability); surface impoundments and tailings ponds must be underlain with a double liner, both layers of which have at least 1 x 10-7 permeability; a blanket-type leachate collection and removal system is required (the liner and leachate collection and removal system for tailings ponds must be able to withstand the ultimate weight of the wastes to be placed there)

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• Precipitation and drainage controls—designed to accommodate one 25-year, 24-hour storm;

precipitation that is not diverted shall be collected and managed through the required leachate collection and recovery system (LCRS), unless the collected fluid does not contain indicator parameters or waste constituents in excess of applicable water quality standards.

Precipitation and drainage controls shall comply with requirements in § 20365 (d and e)

• Closure--final cover graded to be no steeper than 3:1 (vertical to horizontal) with minimum

15 feet wide benches for every fifty feet of vertical height; three layer (foundation, low permeability-1 x 10-6 cm/sec--layer, and erosion resistant layer) or alternative cover design.

• Monitoring--comply with conditions of 27 CCR §§ 20385-20430

The requirements for existing Group A Units are:

• Flood Protection--protect from 100-year peak streamflow

• Construction standards--same as for new Group A units

• Precipitation and drainage controls—design to accommodate one 25-year, 24-hour storm;

precipitation that is not diverted shall be collected and managed through a required LCRS, unless the collected fluid does not contain indicator parameters or waste constituents in excess of applicable water quality standards

• Closure--final cover graded to be no steeper than 3:1 (vertical to horizontal) with minimum

15 feet wide benches for every fifty feet of vertical height; three layer (foundation, low permeability-1 x 10-6 cm/sec--layer, and erosion resistant layer) or alternative cover design.

• Monitoring--comply with conditions of 27 CCR §§ 20385-20430

More detailed requirements are contained in 27 CCR § 22490.

Variances. Exemptions from some provisions of the construction standards based on a dry unit or the presence of no/little/poor groundwater. 27 CCR § 22470(b and c). The dry unit liner/LCRS exemption under 27 CCR § 22470(b) is based on a clear demonstration that leachate will not form or escape from the mining unit. In this case the unit can be exempted from requirements for a liner or LCRS.

Under 27 CCR § 22470(c), Group A wastes may be exempt from liner and leachate collection and removal systems if a comprehensive hydrogeologic investigation demonstrates that natural conditions or containment structures will prevent lateral hydraulic interconnection with natural geologic materials containing groundwater suitable for agricultural, domestic, or municipal use and (1) there are only minor amounts of groundwater underlying the area, or (2) the discharge is in compliance with the applicable water quality control plan. The unit would remain subject to requirements for siting, precipitation and drainage controls, and groundwater, unsaturated zone and surface water quality monitoring.

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In addition, 27 CCR § 20080(b and c) provide for consideration of engineered alternatives to the prescriptive construction and closure standards of 27 CCR. Alternatives are to be considered when a demonstration is made that the prescriptive standard is not feasible and there is a specific engineered alternative that is consistent with the performance goal of the prescriptive standard, and affords equivalent protection against water quality impairment. Feasibility of the prescriptive standard is evaluated by determining if compliance would be unnecessarily burdensome and cost substantially more than engineered alternatives; or the prescriptive standard is impractical and will not promote attainment of applicable performance standards. In evaluating the feasibility, all relevant technical and economic factors such as present and projected costs, and the extent to which groundwater resources would be affected should be considered.

Summary. If the waste is considered Group A and the waste is disposed of into an existing unit such as the south waste rock pile, the unit must meet requirements for the Group A precipitation and drainage controls. In addition, the unit must be located outside of the 100-year flood plain. It will be necessary to conduct monitoring in accordance with 27 CCR §§ 20385-20430. A new unit is subject to the liner and LCRS requirements outlined above, unless the unit qualifies for a variance, described above. In addition, the unit should be closed in accordance with the closure standards under 27 CCR § 21090 or an alternative final cover design.

A.4.2.2 State Exclusion of Mining Waste from Regulation as Hazardous Waste

California's Health and Safety Code (HSC) recognizes the Bevill exclusion, so that wastes which would otherwise be regulated by the California Hazardous Waste Control Law, the California analogue to RCRA, are instead subject only to the requirements of the Toxic Pits Control Act (TPCA) and the requirements of Water Code Section 13172, detailed in 27 CCR §§ 22470-22510. Under Health and Safety Code Section 25143.1(b)(1 & 2), "Wastes from the extraction, beneficiation, and processing of ores and minerals that are not subject to regulation under Subchapter III (commencing with Section 6921) of Chapter 82 of Title 42 of the United States Code are exempt from the requirements of this chapter, except the requirements of Article 9.5 (commencing with Section 25208) and Chapter 6.8 (commencing with Section 25300). The wastes subject to this subdivision are subject to Article 9.5 (commencing with Section 25208) and Chapter 6.8 (commencing with Section 25300) if the wastes would otherwise be classified as hazardous wastes pursuant to Section 25117 and the regulations adopted pursuant to Section 25141."

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A.4.2.3 Toxic Pits Control Act

Under California Health and Safety Code Section 25143.1, Bevill-exempt wastes are exempt from all provisions of the California Health and Safety Code, except the requirements of the Toxics Pits Control Act (TCPA), HSC §§ 25208 et seq. TPCA prohibits the discharge of liquid hazardous wastes or hazardous wastes containing free liquid into a surface impoundment (HSC § 25208.4(a)). TPCA provides an exemption for a surface impoundment into which mining waste is discharged if the discharge is otherwise in compliance with the requirements for mining waste, and the surface impoundment does not pollute or threaten to pollute the waters of the state. TPCA may be an ARAR for some of the alternatives considered in this FS report.

A.4.2.4 California Surface Mining and Reclamation Act of 1975

Pursuant to the state Surface Mining and Reclamation Act (SMARA), the California Department of Conservation, Office of Mine Reclamation has adopted reclamation standards for mining operations in Article 9, Title 14. These standards do not apply to operations that completed reclamation prior to January 15, 1993 or had an approved reclamation plan prior to January 15, 1993. Pertinent requirements include provisions of the following regulations:

• 14 CCR 3703 –protection standards for wildlife habitat

• 14 CCR 3704 - performance standard for backfilling, re-grading, slope stability, and recontouring

• 14 CCR 3705 – performance standards for revegetation

• 14 CCR 3706 – performance standards for drainage, diversion structures, waterways, and erosion control

• 14 CCR 3710 – performance standards for stream protection

• 14 CCR 3713 – performance standards for closure of surface openings

A.4.2.5 Lake County Air Quality Management District Rules and Regulations

Lake County Air Quality Management District rules and regulations, §§ 400-411 (see also 40 CFR § 6.303), include standards for particulate emissions and for nuisances. Specifically, Rule 411 sets standards for discharges of particulate matter from sources other than combustion sources. Rule 430 prohibits the discharge of air contaminants causing nuisances. These regulations are relevant and appropriate for potential fugitive dust emissions during removal activities and/or transport of mine wastes.

APPENDIX B

HELP Modeling of Soil Cover and Earthen Cap with Liner

APPENDIX C

Water Treatment Technical Memorandum

WATER TREATMENT TECHNICAL MEMORANDUM

FOR

OPERABLE UNIT 1

SULPHUR BANK MERCURY MINE SUPERFUND SITE

CLEARLAKE OAKS, CALIFORNIA

Prepared by:

TETRA TECH EM INC.

Prepared for:

U.S. ENVIRONMENTAL PROTECTION AGENCY

Region IX

75 Hawthorne Street San Francisco, California 94105

November 2003 i

CONTENTS

Section Page

ACRONYMS AND ABBREVIATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ii

1.0 INTRODUCTION

2.0 TREATMENT SYSTEM SIZING ANALYSIS

3.0 BENCH SCALE JAR TESTING

4.0 WATER TREATMENT COMPUTER MODELING

5.0 IDENTIFICATION OF POTENTIAL WATER TREATMENT TECHNOLOGY

OR PROCESSES

6.0 SLUDGE AND OTHER TREATMENT RESIDUAL MANAGEMENT

7.0 ESTIMATED COSTS OF WATER TREATMENT ALTERNATIVES

REFERENCES

Appendices

A REVISED YEAR 2000-2001 HERMAN IMPOUNDMENT WATER BALANCE

B CLEARLAKE 4SE 100-YEAR PRECIPITATION PROJECTIONS

C JAR TESTING WORK PLAN

Figures

1-1 Site Location Map 5-1 Water Treatment Alternative 1 Schematic 5-2 Water Treatment Alternative 2 Schematic 5-3 Water Treatment Alternative 3 Schematic 5-4 Water Treatment Alternative 4 Schematic

Tables

1-1 Herman Impoundment Water Quality 3-1 Herman Impoundment Water Treatment Jar Testing – Water Analysis 3-2 Herman Impoundment Water Treatment Jar Testing – Sludge Analysis 3-3 Herman Impoundment Water Treatment Jar Testing -- Lime Demand and Solids Generation 4-1 EQ3/6 Predicted Metal Removal at Varying pH Levels 4-2 EQ3/6 Predicted Gypsum Precipitation at Varying pH Levels 4-3 EQ3/6 Predicted Results of Mixing Neutralized Impoundment Water with Reclaimed Wastewater at Various Dilution Ratios 7-1 Preliminary Cost Estimate for Water Treatment Alternative 1 7-2 Preliminary Cost Estimate for Water Treatment Alternative 2 7-3 Preliminary Cost Estimate for Water Treatment Alternative 3 7-4 Preliminary Cost Estimate for Water Treatment Alternative 4 ii

ACRONYMS AND ABBREVIATIONS

ARAR Applicable and relevant and appropriate requirements

CERCLA Comprehensive Environmental Response Cleanup and Liability Act cy Cubic Yard

EPA U.S. Environmental Protection Agency

FS Feasibility Study

LACOSAN Lake County Sanitation District

LLNL Lawrence Livermore National Laboratory

MCL Maximum Contaminant Levels

MGD Million gallons per day mg/kg Milligrams per kilograms mg/L Milligrams per liter

OU Operable Unit

RCRA Resource Conservation and Recovery Act

RI Remedial Investigation

RI/FS Remedial Investigation/Feasibility Study rpm Revolutions per minute

SEG Southeast Geysers

SBMM Sulphur Bank Mercury Mine

TtEMI Tetra Tech EM Inc.

:g/L Micrograms per liter (equivalent to parts per billion)

1.0 INTRODUCTION

The Sulphur Bank Mercury Mine (SBMM) Superfund Site near Clearlake Oaks, California was placed on the National Priorities List in August 1990 and is currently owned by the Bradley Mining Company, the last operator of the mine. Mining of sulfur and mercury at SBMM occurred periodically from 1865 through 1957. Clear Lake is located in Lake County, California, approximately 100 miles north of San

Francisco. Clear Lake is one of the best bass fishing locations in the U.S. and the largest fresh water lake wholly within California.