9VAC25-151-150. Sector G - Metal mining (ore mining and dressing).
A. Discharges covered under this section. The requirements listed under this section apply to stormwater discharges associated with industrial activity from active, temporarily inactive and inactive metal mining and ore dressing facilities including mines abandoned on federal lands, as classified under SIC Major Group 10. Coverage is required for facilities that discharge stormwater that has come into contact with, or is contaminated by, any overburden, raw material, intermediate product, finished product, byproduct, or waste product located on the site of the operation. SIC Major Group 10 includes establishments primarily engaged in mining of ores, developing mines, or exploring for metallic minerals (ores) and also includes ore dressing and beneficiating operations, whether performed at colocated, dedicated mills or at separate mills, such as custom mills. For the purposes of this section, the term "metal mining" includes any of the separate activities listed above. Covered discharges include:
1. All stormwater discharges from inactive facilities;
2. Stormwater discharges from the following areas of active and temporarily inactive metal mining facilities: waste rock and overburden piles if composed entirely of stormwater and not combining with mine drainage; topsoil piles; off-site haul and access roads; on-site haul and access roads constructed of waste rock and overburden if composed entirely of stormwater and not combining with mine drainage; on-site haul and access roads not constructed of waste rock, overburden, or spent ore except if mine drainage is used for dust control; runoff from tailings dams and dikes when not constructed of waste rock or tailings and no process fluids are present; runoff from tailings dams or dikes when constructed of waste rock or tailings and no process fluids are present if composed entirely of stormwater and not combining with mine drainage; concentration building if no contact with material piles; mill site if no contact with material piles; office or administrative building and housing if mixed with stormwater from industrial area; chemical storage area; docking facility if no excessive contact with waste product that would otherwise constitute mine drainage; explosive storage; fuel storage; vehicle and equipment maintenance area and building; parking areas (if necessary); power plant; truck wash areas if no excessive contact with waste product that would otherwise constitute mine drainage; unreclaimed, disturbed areas outside of active mining area; reclaimed areas released from reclamation bonds prior to December 17, 1990; and partially or inadequately reclaimed areas or areas not released from reclamation bonds;
3. Stormwater discharges from exploration and development of metal mining and ore dressing facilities; and
4. Stormwater discharges from facilities at mining sites undergoing reclamation.
B. Limitations on coverage. Stormwater discharges from active metal mining facilities that are subject to the effluent limitation guidelines for the Ore Mining and Dressing Point Source Category (40 CFR Part 440) are not authorized by this permit.
Note: Discharges that come in contact with overburden and waste rock are subject to 40 CFR Part 440, providing: the discharges drain to a point source (either naturally or as a result of intentional diversion), and they combine with mine drainage that is otherwise regulated under 40 CFR Part 440. Discharges from overburden and waste rock can be covered under this permit if they are composed entirely of stormwater and do not combine with sources of mine drainage that are subject to 40 CFR Part 440.
C. Special Conditions. Prohibition of nonstormwater discharges. In addition to the general prohibition of nonstormwater discharges in Part I B 1, the following discharge is not covered by this permit: adit drainage. Contaminated seeps and springs discharging from waste rock dumps that do not directly result from precipitation events are also not authorized by this permit.
D. Special definitions. The following definitions are not intended to supersede the definitions of active and inactive mining facilities established by 40 CFR 122.26(b)(14)(iii), and are only for this section of the general permit:
"Active metal mining facility" means a place where work or other related activity to the extraction, removal, or recovery of metal ore is being conducted. For surface mines, this definition does not include any land where grading has returned the earth to a desired contour and reclamation has begun.
"Active phase" means activities including the extraction, removal, or recovery of metal ore. For surface mines, this definition does not include any land where grading has returned the earth to a desired contour and reclamation has begun.
"Construction phase" means the building of site access roads and removal of overburden and waste rock to expose mineable minerals. The construction phase is not considered part of "mining operations."
"Exploration phase" entails exploration and land disturbance activities to determine the financial viability of a site. The exploration phase is not considered part of "mining operations."
"Final stabilization" - a site or portion of a site is "finally stabilized" when all applicable federal and state reclamation requirements have been implemented.
"Inactive metal mining facility" means a site or portion of a site where metal mining or milling occurred in the past but is not an active facility as defined in this permit, and where the inactive portion is not covered by an active mining permit issued by the applicable federal or state agency. An inactive metal mining facility has an identifiable owner or operator. Sites where mining claims are being maintained prior to disturbances associated with the extraction, beneficiation, or processing of mined materials and sites where minimal activities are undertaken for the sole purpose of maintaining a mining claim are not considered either active or inactive mining facilities and do not require a VPDES industrial stormwater permit.
"Mining operation" consists of the active and temporarily inactive phases and the reclamation phase, but excludes the exploration and construction phases.
"Reclamation phase" means activities undertaken, in compliance with applicable mined land reclamation requirements, following the cessation of the "active phase," intended to return the land to an appropriate post-mining land use in order to meet applicable federal and state reclamation requirements. The reclamation phase is considered part of "mining operations."
"Temporarily inactive metal mining facility" means a site or portion of a site where metal mining or milling occurred in the past but currently are not being actively undertaken, and the facility is covered by an active mining permit issued by the applicable federal or state agency.
E. Clearing, grading, and excavation activities. Clearing, grading, and excavation activities being conducted as part of the exploration and construction phase of mining activities are covered under this permit.
1. Management practices for clearing, grading, and excavation activities.
a. Selecting and installing control measures. A combination of erosion and sedimentation control measures are required to achieve maximum pollutant prevention and removal. All control measures shall be properly selected, installed, and maintained in accordance with any relevant manufacturer specifications and good engineering practices.
b. Good housekeeping. Litter, debris, and chemicals shall be prevented from becoming a pollutant source in stormwater discharges.
c. Retention and detention of stormwater runoff. For drainage locations serving more than one acre, sediment basins or temporary sediment traps should be used. At a minimum, silt fences, vegetative buffer strips, or equivalent sediment controls are required for all down slope boundaries (and for those side slope boundaries deemed appropriate as dictated by individual site conditions) of the development area unless a sediment basin providing storage for a calculated volume of runoff from a two-year, 24-hour storm or 3,600 cubic feet of storage per acre drained is provided. Sediment shall be removed from sediment traps or sedimentation ponds when the design capacity has been reduced by 50%.
d. Temporary stabilization of disturbed areas. Stabilization measures shall be initiated immediately in portions of the site where development activities have temporarily ceased, but in no case more than 14 days after the clearing, grading, and excavation activities in that portion of the site have temporarily ceased. In arid, semi-arid, and drought-stricken areas, or in areas subject to snow or freezing conditions, where initiating perennial vegetative stabilization measures is not possible within 14 days after mining, exploration, or construction activity has temporarily ceased, final temporary vegetative stabilization measures shall be initiated as soon as practicable. Until temporary vegetative stabilization is achieved, interim measures such as erosion control blankets with an appropriate seed base and tackifiers shall be employed. In areas of the site where exploration or construction has permanently ceased prior to active mining, temporary stabilization measures shall be implemented to minimize mobilization of sediment or other pollutants until such time as the active mining phase commences.
2. Requirements for inspection of clearing, grading, and excavation activities.
a. Inspection frequency. Inspections shall be conducted at least once every seven calendar days or at least once every 14 calendar days and within 24 hours of the end of a storm event of 0.5 inches or greater. Inspection frequency may be reduced to at least once every month if the entire site is temporarily stabilized, if runoff is unlikely due to winter (e.g., site is covered with snow or ice) or frozen conditions, or construction is occurring during seasonal dry periods in arid areas and semi-arid areas.
b. Location of inspections. Inspections shall include all areas of the site disturbed by clearing, grading, and excavation activities and areas used for storage of materials that are exposed to precipitation. Sedimentation and erosion control measures identified in the SWPPP shall be observed to ensure proper operation. Discharge locations shall be inspected to ascertain whether erosion control measures are effective in preventing significant impacts to surface waters, where accessible. Where discharge locations are inaccessible, nearby downstream locations shall be inspected to the extent that such inspections are practicable. Locations where vehicles enter or exit the site shall be inspected for evidence of off-site sediment tracking.
c. Inspection reports. For each inspection required above, an inspection report shall be completed. At a minimum, the inspection report shall include:
(1) The inspection date;
(2) Names, titles, and qualifications of personnel making the inspection;
(3) Weather information for the period since the last inspection (or note if it is the first inspection) including a best estimate of the beginning of each storm event, duration of each storm event, approximate amount of rainfall for each storm event (in inches), and whether any discharges occurred;
(4) Weather information and a description of any discharges occurring at the time of the inspection;
(5) Location(s) of discharges of sediment or other pollutants from the site;
(6) Location(s) of control measures that need to be maintained;
(7) Location(s) of control measures that failed to operate as designed or proved inadequate for a particular location;
(8) Location(s) where additional control measures are needed that did not exist at the time of inspection; and
(9) Corrective action(s) required, including any changes to the SWPPP necessary and implementation dates.
A record of each inspection and of any actions taken in accordance with this section shall be retained as part of the SWPPP for at least three years from the date that permit coverage expires or is terminated. The inspection reports shall identify any incidents of noncompliance with the permit conditions. Where a report does not identify any incidents of noncompliance, the report shall contain a certification that the clearing, grading, and excavation activities are in compliance with the SWPPP and this permit. The report shall be signed in accordance with Part II K of the permit.
3. Requirements for cessation of clearing, grading, and excavation activities.
a. Inspections and maintenance. Inspections and maintenance of control measures, including BMPs, associated with clearing, grading, and excavation activities being conducted as part of the exploration and construction phase of a mining operation shall continue until final stabilization has been achieved on all portions of the disturbed area, or until the commencement of the active mining phase for those areas that have been temporarily stabilized as a precursor to mining.
b. Final stabilization. Stabilization measures shall be initiated immediately in portions of the site where exploration or construction activities have permanently ceased, but in no case more than 14 days after the exploration or construction activity in that portion of the site has permanently ceased. In arid, semi-arid, and drought-stricken areas, or in areas subject to snow or freezing conditions, where initiating perennial vegetative stabilization measures is not possible within 14 days after exploration or construction activity has permanently ceased, final vegetative stabilization measures shall be initiated as soon as possible. Until final stabilization is achieved temporary stabilization measures, such as erosion control blankets with an appropriate seed base and tackifiers, shall be used.
F. Stormwater pollution prevention plan requirements for active, inactive, and temporarily inactive metal mining facilities and sites undergoing reclamation. In addition to the requirements of Part III, the plan shall include, at a minimum, the following items.
1. Site description.
a. Activities at the facility. A description of the mining and associated activities taking place at the site that can potentially affect stormwater discharges covered by this permit. The description shall include a general description of the location of the site relative to major transportation routes and communities.
b. Site map. The site map shall identify the locations of the following, as appropriate: mining and milling site boundaries; access and haul roads; an outline of the drainage areas of each stormwater outfall within the facility, and an indication of the types of discharges from the drainage areas; location(s) of all permitted discharges covered under an individual VPDES permit; outdoor equipment storage, fueling and maintenance areas; materials handling areas; outdoor manufacturing, storage or material disposal areas; outdoor storage areas for chemicals and explosives; areas used for storage of overburden, materials, soils or wastes; location of mine drainage (where water leaves mine) or any other process water; tailings piles and ponds, both proposed and existing; heap leach pads; points of discharge from the property for mine drainage and process water; surface waters; boundary of tributary areas that are subject to effluent limitations guidelines; and location(s) of reclaimed areas.
2. Summary of potential pollutant sources. For each area of the mine or mill site where stormwater discharges associated with industrial activities occur, the plan shall identify the types of pollutants likely to be present in significant amounts (e.g., heavy metals, sediment). The following factors shall be considered: the mineralogy of the ore and waste rock (e.g., acid forming); toxicity and quantity of chemicals used, produced or discharged; the likelihood of contact with stormwater; vegetation of site, if any; and history of significant leaks and spills of toxic or hazardous pollutants. A summary of any existing ore or waste rock and overburden characterization data and test results for potential generation of acid rock shall also be included. If the ore or waste rock and overburden characterization data are updated due to a change in the ore type being mined, the SWPPP shall be updated with the new data.
3. Stormwater controls.
a. Routine facility inspections. Except for areas subject to clearing, grading, and excavation activities subject to subdivision E 2 of this section, sites shall be inspected at least quarterly unless adverse weather conditions make the site inaccessible. The requirement for routine facility inspections is waived for facilities that have maintained an active VEEP E3/E4 status.
b. Employee training. Employee training shall be conducted at least annually at active mining and temporarily inactive sites. All employee training shall be documented in the SWPPP.
c. Structural control measures. In addition to the control measures required by Part III B 4, each of the following control measures shall be considered in the SWPPP. The potential pollutants identified in subdivision 1 b of this subsection shall determine the priority and appropriateness of the control measures selected. If control measures are implemented or planned but are not listed here (e.g., substituting a less toxic chemical for a more toxic one), descriptions of them shall be included in the SWPPP.
(1) Stormwater diversion. A description of how and where stormwater will be diverted away from potential pollutant sources to prevent stormwater contamination. Control measure options may include the following: interceptor dikes and swales; diversion dikes, curbs and berms; pipe slope drains; subsurface drains; drainage and stormwater conveyance systems (channels or gutters, open top box culverts and waterbars; rolling dips and road sloping; roadway surface water deflector and culverts) or equivalent measures.
(2) Capping. When capping of a contaminant source is necessary, the source being capped and materials and procedures used to cap the contaminant source shall be identified.
(3) Treatment. If treatment of a stormwater discharge is necessary to protect water quality, include a description of the type and location of stormwater treatment that will be used. Stormwater treatments include the following: chemical or physical systems; oil and water separators; artificial wetlands; etc. The permittee is encouraged to use both passive and active treatment of stormwater runoff. Treated runoff may be discharged as a stormwater source regulated under this permit provided the discharge is not combined with discharges subject to effluent limitation guidelines for the Ore Mining and Dressing Point Source Category (40 CFR Part 440).
(4) Certification of discharge testing. The permittee shall test or evaluate all outfalls covered under this permit for the presence of specific mining-related nonstormwater discharges such as seeps or adit discharges or discharges subject to effluent limitations guidelines (e.g., 40 CFR Part 440), such as mine drainage or process water. Alternatively (if applicable), the permittee may certify in the SWPPP that a particular discharge composed of commingled stormwater and nonstormwater is covered under a separate VPDES permit; and that permit subjects the nonstormwater portion to effluent limitations prior to any commingling. This certification shall identify the nonstormwater discharges, the applicable VPDES permit(s), the effluent limitations placed on the nonstormwater discharge by the permit(s), and the points at which the limitations are applied.
G. Termination of permit coverage.
1. Termination of permit coverage for sites reclaimed after December 17, 1990. A site or a portion of a site that has been released from applicable state or federal reclamation requirements after December 17, 1990, is no longer required to maintain coverage under this permit. If the site or portion of a site reclaimed after December 17, 1990, was not subject to reclamation requirements, the site or portion of the site is no longer required to maintain coverage under this permit if the site or portion of the site has been reclaimed as defined in subdivision 2 of this subsection.
2. Termination of permit coverage for sites reclaimed before December 17, 1990. A site or portion of a site that was released from applicable state or federal reclamation requirements before December 17, 1990, or that was otherwise reclaimed before December 17, 1990, is no longer required to maintain coverage under this permit if the site or portion of the site has been reclaimed. A site or portion of a site is considered to have been reclaimed if: (i) stormwater runoff that comes into contact with raw materials, intermediate byproducts, finished products, and waste products does not have the potential to cause or contribute to violations of state water quality standards, (ii) soil-disturbing activities related to mining at the sites or portion of the site have been completed, (iii) the site or portion of the site has been stabilized to minimize soil erosion, and (iv) as appropriate depending on location, size, and the potential to contribute pollutants to stormwater discharges, the site or portion of the site has been revegetated, will be amenable to natural revegetation, or will be left in a condition consistent with the post-mining land use.
H. Inactive and unstaffed sites. Permittees in Sector G seeking to exercise a waiver from the quarterly visual assessment and routine facility inspection requirements for inactive and unstaffed sites (including temporarily inactive sites) are conditionally exempt from the requirement to certify that "there are no industrial materials or activities exposed to stormwater" in Part I A 4.
This exemption is conditioned on the following:
1. If circumstances change and the facility becomes active or staffed, this exception no longer applies and the permittee shall immediately begin complying with the quarterly visual assessment and routine facility inspection requirements; and
2. The board retains the authority to revoke this exemption and the monitoring waiver when it is determined that the discharge causes, has a reasonable potential to cause, or contributes to an instream excursion above an applicable water quality standard, including designated uses.
Subject to the two conditions in subdivisions 1 and 2 of this subsection, if a facility is inactive and unstaffed, the permittee is waived from the requirement to conduct quarterly visual assessments and routine facility inspections. The permittee is not waived from conducting the Part III E comprehensive site inspection. The board encourages the permittee to inspect the site more frequently when there is reason to believe that severe weather or natural disasters may have damaged control measures.
I. Benchmark monitoring and reporting requirements. Note: There are no benchmark monitoring requirements for inactive and unstaffed sites that have received a waiver in accordance with Part I A 4 (Inactive and unstaffed sites).
1. Copper ore mining and dressing facilities. Active copper ore mining and dressing facilities are required to monitor their stormwater discharges for the pollutants of concern listed in Table 150-1 below.
2. Discharges from waste rock and overburden piles at active sites. Discharges from waste rock and overburden piles at active sites shall be analyzed for the parameters listed in Table 150-2. Facilities shall also monitor for the parameters listed in Table 150-3. The director may also notify the facility that additional monitoring must be performed to accurately characterize the quality and quantity of pollutants discharged from the waste rock or overburden piles.
§ 62.1-44.15 of the Code of Virginia; § 402 of the federal Clean Water Act; 40 CFR Parts 122, 123, and 124.
Derived from Virginia Register Volume 15, Issue 9, eff. June 30, 1999; amended, Virginia Register Volume 20, Issue 16, eff. July 1, 2004; Volume 21, Issue 2, eff. November 3, 2004; Volume 25, Issue 19, eff. June 24, 2009; Volume 30, Issue 11, eff. July 1, 2014.