(A) Mining of aggregate and minerals within vulnerable portions of a drinking water supply management area (DWSMA) may occur if care is used to ensure that:
(1) The mining operations;
(2) Management of the mining area; and
(3) Reclamation efforts do not present a serious risk to groundwater quality.
(B) The following issues should be considered when conducting aggregate or mineral mining within vulnerable portion of a drinking water supply management area.
(1) The movement of disease organisms into the aquifer within the time period that they remain viable in groundwater. The United States Environmental Protection Agency states that human pathogens may remain viable in groundwater for one to two years. Therefore, sewage treatment systems and/or surface water runoff into aggregate or mineral mining areas that are located in the one- to two-year time of travel for a water supply well should be viewed as a potential source of pathogen recharge to the aquifer.
(a) Surface water runoff shall be controlled to avoid infiltration within all vulnerable portions of a DWSMA of a public water supply well.
(b) Onsite sewage treatment systems shall be excluded from the one-year time of travel area of a DWSMA.
(2) Contamination related to fuel and fuel-breakdown products.
(a) Fuel storage and refueling operation shall not occur in areas where geologic cover has been removed or in mining areas.
(b) Only above-ground storage tanks shall be allowed with approved containment outside the mining area.
(c) All tanks, regardless of size, must meet city and/or MPCA rules or regulations that apply to tanks with capacity greater than 1,000 gallons.
(d) An emergency spill response plan shall be in place that identifies:
1. How a response to a spill will be implemented;
2. The parties that will be involved; and
3. How the public water supplier will be informed.
(3) Contamination related to storage of equipment, wastes, and hazardous materials.
(a) Equipment shall not be stored or serviced in vulnerable portions of a DWSMA unless conducted on an impervious pad or similar surface.
(b) Waste materials shall not be stored and processed within vulnerable portions of a DWSMA unless conducted on an impervious pad without secondary containment.
(c) Explosives or other materials used in extractive mining processes shall not be stored or processed within the vulnerable portions of a DWSMA unless conducted on an impervious pad with secondary containment.
(d) All generated wastes shall be processed in accordance to State and local requirements.
(e) Storage and processing of recycled bituminous materials shall not be stored or processed within the vulnerable portions of a DWSMA unless conducted on an impervious pad with secondary containment.
(f) Land spreading of animal manures, industrial wastes, or municipal sludge shall not be allowed within vulnerable portions of a DWSMA.
(g) Landfills shall not be located in vulnerable portions of a DWSMA.
(4) Operation of a bituminous batch plant.
(a) An asphalt batch plant shall not be located within the vulnerable portions of a DWSMA unless located on an impervious pad with secondary containment.
(b) Spraying of truck boxes with oil shall not be conducted within the vulnerable portions of a DWSMA unless located on an impervious pad with secondary containment.
(5) Groundwater withdrawal related to mining operations.
(a) 1. Prior to locating a well that may be used to provide wash water or to dewater the site, the applicant shall address the impacts that groundwater pumping may have on altering the DWSMA boundary or vulnerability of the public water supply well(s).
2. A groundwater appropriation permit is required from the MnDNR prior to any use of a high capacity well associated with a mining operation.
(b) Wells in mining areas: Wells that are constructed into or through the aquifer(s) used by a public water supply well(s) may become direct pathways for contaminants to enter the aquifer if:
1. They were not properly constructed;
2. They are not adequately maintained; or
3. Contaminants are stored or used too close to them. Therefore, all wells within proposed mining areas should (1) be accurately located, (2) have well construction determined, and (3) determine status of use.
(c) In 1999, the US EPA finalized the underground injection control regulations for class v injection wells, known as the Class V Rule, Phase 1. The Class V Rule establishes minimum federal standards for two types of Class V wells that are of concern in DWSMAs: large capacity cesspools and motor vehicle waste disposal wells. These types of wells are also known as shallow disposal systems. The Class V Rule also establishes an inventory and permitting process for large capacity septic systems.
1. Prior to mining, an inventory of all wells, including shallow disposal systems, shall be conducted within the portions of a DWSMA proposed for mining activities.
2. Prior to the start of mining operations, all water supply wells located within the proposed area to be mined shall be reviewed by a licensed well driller to determine if the well(s) require repair or sealing in accordance to Minn. Rules Chapter 4725.
3. All potential contaminant sources shall meet state required setbacks to all wells.
4. Construction of new large-capacity cesspools and/or motor vehicle waste disposal wells are prohibited within a DWSMA.
5. Existing large capacity cesspools and/or motor vehicle waste disposal wells must be permitted by the US EPA.
(6) Illegal dumping or other uses of mining areas.
(a) Mining areas shall be managed to prevent the public form using them to dispose of waste, vehicles and equipment, demolition debris, industrial/commercial waste, or other unwanted material.
(b) Mining areas shall not be used for recreational purposes such as off-road vehicles, discharging firearms or other similar types of land uses unless specifically allowed as part of the mining permitting process.
(c) Mining areas shall not be used for stockpiling or spreading of animal manures.
(7) Site reclamation.
(a) Plans for reclaiming land that is mined or stripped of geologic cover shall address how future land use or the surface water drainage will be controlled to reduce the direct infiltration of contaminants into the aquifer.
(b) Site reclamation plans shall use a minimum of two-foot contours.
(c) Proposed land-use practices shall be evaluated for their potential risk to groundwater quality.
(d) Surface drainage from adjacent properties shall be diverted away from the mining area so that it does not infiltrate into the ground or directly enter groundwater in areas where aggregate or minerals are exposed or where the water table is exposed in a former pit.
(e) Reclamation shall be phased in as mining progresses, with public water supply well time-of-travel areas having the highest priority for reclamation.
(f) Topsoil shall be replaced over all portions of a vulnerable SWSMA to a depth sufficient to support vegetation.
(g) Vegetation used for reclamation shall be native species or similar species that do not require regular or seasonal applications of nutrients or pesticides.
(C) No mining, extraction, and/or excavation shall be allowed within the one-year time of travel zone or within 1,000 feet of a public supply well.
(Ord. 102, passed 10-24-2007)