PURPOSE: This rule complies with section 444.535.1(5), RSMo by setting forth water quality standards and effluent limitations for protection of the hydrologic system.

PUBLISHER’S NOTE: The secretary of state has determined that the publication of the entire text of the material which is incorporated by reference as a portion of this rule would be unduly cumbersome or expensive. Therefore, the material which is so incorporated is on file with the agency who filed this rule, and with the Office of the Secretary of State. Any interested person may view this material at either agency’s headquarters or the same will be made available at the Office of the Secretary of State at a cost not to exceed actual cost of copy reproduction. The entire text of the rule is printed here. This note refers only to the incorporated by reference material.

1. (1) General. The operator shall plan and conduct coal mining and reclamation operations to minimize disturbance to the prevailing hydrologic balance in order to prevent longterm adverse changes in the hydrologic balance that could result from coal strip mining and reclamation operations, both onand offsite. Changes in water quality and quantity, in the depth to groundwater and in the location of surface water drainage channels shall be minimized so that the post-mining land use of the disturbed land is not adversely affected and applicable federal and state statutes and regulations are not violated. The operator shall conduct operations so as to minimize water pollution and, where necessary, shall use treatment methods to control water pollution. The operator shall employ coal strip mining and reclamation practices that will prevent or minimize water pollution and changes in flows in preference to the use of water treatment facilities. Practices to control and minimize pollution include, but are not limited to, stabilizing disturbed areas through grading, diverting runoff, achieving quick growing stands of temporary vegetation, lining drainage channels with rock or vegetation, mulching, sealing acidand toxic-forming materials and selectively placing waste materials in backfill areas. If pollution can be controlled only by treatment, the operator shall operate and maintain the necessary water treatment facilities for as long as treatment is required.
2. (2) Sedimentation Ponds. All surface drainage from the disturbed area, including disturbed areas that have been graded, seeded or planted, shall be passed through a sedimentation pond or a series of sedimentation ponds before leaving the permit area. Sedimentation ponds shall be retained until drainage from the disturbed area has met the water quality requirements of this section and the revegetation requirements of 10 CSR 40- 2.090 have been met. Exemptions from this requirement may be granted only when the disturbed drainage area within the total disturbed area is small and if the operator shows that sedimentation ponds are not necessary to meet the effluent limitations of this rule and to maintain water quality in downstream receiving waters. For purposes of this section only, disturbed areas shall not include those areas in which only diversion ditches, sedimentation ponds or roads are installed in accordance with this section and the upstream area is not otherwise disturbed by the operator. Sedimentation ponds required by this rule shall be constructed in accordance with section (6) of this rule in appropriate locations prior to any mining in the affected drainage area in order to control sedimentation or otherwise treat water in accordance with this rule. Discharges from areas disturbed by surface coal mining and reclamation operations must meet all applicable federal and state laws and at a minimum, the following numerical effluent limitations: Effluent Limitations, in Milligrams Per Liter, mg/l, Except for pH Average of Daily Values for 30 Effluent Maximum Consecutive Characteristics Allowable* Discharge Days*

Iron, total 7.0 3.5 Manganese,** total 4.0 2.0 Total suspended solids 70.0 35.0 pH*** Within the range _____ 6.0—9.0

*Based on representative sampling **Only applies to discharges into receiving waters with a pH of 6.0 or lower ***Where the application of neutralization and sedimentation treatment technology results in inability to comply with the manganese limitations set forth, the commission may allow the pH level in the discharge to exceed to a small extent the upper limit of 9.0 in order, that the manganese limitations will be achieved

1. (A) Any overflow or other discharge of surface water from the disturbed area within the permit area demonstrated by the operator to result from a precipitation event larger than a ten (10)-year, twenty-four (24) hour frequency event will not be subject to the effluent limitations of this rule.
2. (B) The operator shall install, operate and maintain adequate facilities to treat any water discharged from the disturbed area that violates applicable federal or state laws or regulations, or the limitations of this section. If the pH of waters to be discharged from the disturbed area is normally less than 6.0, an automatic lime feeder or other neutralization process as approved in the reclamation plan shall be installed, operated and maintained. If it is found that small and infrequent treatment requirements to meet applicable standards do not necessitate use of an automatic neutralization process and that the mine normally produces less than five hundred (500) tons of coal per day, then the use of a manual system may be approved in the reclamation plan if the operator ensures consistent and timely treatment.

1. (3) Surface Water Monitoring.

   1. (A) The operator shall submit in the reclamation plan a surface water monitoring program which meets the following requirements:

      1. 1. Provides adequate monitoring of all

discharge from the disturbed area;

1. 2. Provides adequate data to describe the

likely daily and seasonal variation in discharges from the disturbed area in terms of water flow, pH, total iron, total manganese and total suspended solids;

1. 3. Provides monitoring at appropriate

frequencies to measure normal and abnormal variations in concentrations;

1. 4. Provides an analytical quality control

system including standard methods of analysis such as those specified in 40 CFR 136; and

1. 5. Provides a regular report of all mea-

surements to the commission within sixty (60) days of sample collection unless violations of permit conditions occur in which case the commission shall be notified immediately after receipt of analytical results by the operator. If the discharge is subject to regulation by a federal or state permit issued in compliance with the Federal Water Pollution Control Act Amendment of 1972 (33 USC sections 1251–1378), a copy of the completed reporting form supplied to meet the National Pollutant Discharge Elimination System (NPDES) permit requirements may be submitted to the commission to satisfy the reporting requirements if the data meets the sampling frequency and other requirements of this paragraph.

1. (B) After disturbed areas have been regraded and stabilized in accordance with this chapter, the operator shall monitor surface water flow and quality. Data from this monitoring shall be used to demonstrate that the quality and quantity of runoff without treatment will be consistent with the requirement of this rule to minimize disturbance to the prevailing hydrologic balance and with the requirements of this chapter to attain the approved postmining land use. These data shall provide a basis for approval by the commission for removal of water quality of flow control systems and for determining when the requirements of this section are met. The approved reclamation plan shall set forth the nature of data, frequency of collection and reporting requirements proposed to comply with this subsection.
2. (C) Equipment, structures and other measures necessary to accurately measure and sample the quality and quantity of surface water discharges from the disturbed area of the permit area shall be properly installed, maintained and operated and shall be removed when no longer required.

1. (4) Diversion and Conveyance of Overland Flow Away From Disturbed Areas. In order to minimize erosion and to prevent or remove water from contracting toxic-producing deposits, overland flow from undisturbed areas, if required and approved in the reclamation plan, may be diverted away from disturbed areas by means of temporary or per- 10 CSR 40-2

manent diversion structures. The following requirements shall be met:

1. (A) Temporary diversion structures are those used during mining and reclamation. When no longer needed, these structures shall be removed and the area reclaimed. Temporary diversion structures shall be constructed to safely pass the peak runoff from a precipitation event with a ten (10)-year recurrence interval;
2. (B) Permanent diversion structures are those remaining after mining and reclamation, and approved for retention in the reclamation plan and by other appropriate state and federal agencies. To protect fills and property, and to avoid danger to public health and safety, permanent diversion structures shall be constructed to safely pass the peak runoff from a precipitation event with a one hundred (100)-year recurrence interval. Permanent diversion structures shall be constructed with gently sloping banks that are stabilized by vegetation. Asphalt, concrete or other similar linings shall not be used unless specifically required to prevent seepage or to provide stability and are approved in the reclamation plan; and
3. (C) Diversions shall be designed, constructed and maintained in a manner to prevent additional contributions of suspended solids to streamflow or to runoff outside the permit area to the extent possible, using the best technology currently available. In no event shall these contributions be in excess of requirements set by applicable state or federal law. Appropriate sediment control measures for these diversions shall include, but not be limited to, maintenance of appropriate gradients, channel lining, revegetation, roughness structures and detention basins.

1. (5) Stream Channel Diversions.

   1. (A) Flow from perennial and intermittent streams within the permit area may be diverted only when the diversions are approved in the reclamation plan and they are in compliance with local, state and federal statutes and regulations. When streamflow is allowed to be diverted, the new stream channel shall be designed and constructed to meet the following requirements:

      1. 1. The average stream gradient shall be

maintained and the channel designed, constructed and maintained to remain stable and to prevent additional contributions of suspended solids to streamflow or to runoff outside the permit area to the extent possible, using the best technology currently available. In no event shall those contributions be in excess of requirements set by applicable state or federal law. Erosion control structures such as channel lining structures, retension basins and artificial channel roughness structures shall be used only when approved in the reclamation plan for temporary diversions where necessary or for permanent diversions where they are stable and will require only infrequent maintenance;

1. 2. Channel, bank and flood-plain con-

figurations shall be adequate to safely pass the peak runoff of a precipitation event with a ten (10)-year recurrence interval for temporary diversions and a one hundred (100)-year recurrence interval for permanent diversions; and

1. 3. Fish and wildlife habitat, and water

and vegetation of significant value for wildlife shall be protected in consultation with appropriate state and federal fish and wildlife management agencies.

1. (B) All temporary diversion structures shall be removed and the affected land regraded and revegetated consistent with the requirements of 10 CSR 40-2.040 and 10 CSR 40-2.090. At the time those diversions are removed, the operator shall ensure that downstream water treatment facilities previously protected by the diversion are modified or removed to prevent overtopping or failure of the facilities.
2. (C) Buffer Zone. No land within one hundred feet (100') of an intermittent or perennial stream shall be disturbed by coal strip mining and reclamation operations unless authorized by the reclamation plan. The area not to be disturbed shall be designated a buffer zone and marked as specified in 10 CSR 40-2.020.

1. (6) Sediment Control Measures. Appropriate sediment control measures shall be designed, constructed and maintained to prevent additional contributions of sediment to streamflow or to runoff outside the permit area to the extent possible, using the best technology currently available. Sediment control measures may include, but are not limited to: sedimentation ponds, diversion structures, sediment traps, straw dikes, riprap, check dams, vegetative filters, dugout, ponds and chemical treatment. Sedimentation ponds may be used individually or in a series.
2. (7) Discharge Structures. Discharges from sedimentation ponds and diversions shall be controlled, where necessary, using energy dissipators, surge ponds and other devices to reduce erosion and prevent deepening or enlargement of stream channels and to minimize disturbances to the hydrologic balance.

3. (8) Acid and Toxic Materials. Drainage from acidand toxic-forming mine waste materials and spoils into ground and surface water shall be avoided by—

   1. (A) Identifying, burying and treating where necessary, spoil or other materials that will be toxic to vegetation or that will adversely affect water quality if not treated or buried. This material shall be disposed of in accordance with the provisions of 10 CSR 40- 2.040(10);
   2. (B) Preventing or removing water from contact with acidand toxic-forming materials;
   3. (C) Burying or otherwise treating all toxic or harmful materials within thirty (30) days of exposure, if those materials are subject to wind and water erosion. If storage of those materials is approved, the materials shall be placed on impermeable material and protected from erosion and contact with surface water. Coal waste ponds and other coal waste materials shall be maintained according to subsection (8)(D) and 10 CSR 40-2.070 shall apply;
   4. (D) Burying or otherwise treating waste materials from coal preparation plants no later than ninety (90) days after the cessation of the filling of the disposal area. Burial or treatment shall be in accordance with 10 CSR 40-2.040(10); and
   5. (E) Casing, sealing or otherwise managing boreholes, shafts, wells and auger holes or other more or less horizontal holes to prevent pollution of surface or ground water and to prevent mixing of groundwaters of significantly different quality. All boreholes that are within the permit area but are outside the coal strip mining area or which extend beneath the coal to be mined and into water bearing strata shall be plugged permanently in a manner approved in the reclamation plan unless the boreholes have been approved for use in monitoring.

4. (9) Groundwater.

   1. (A) Recharge Capacity of Reclaimed Lands. The disturbed area shall be reclaimed to restore approximate premining recharge capacity through restoration of the capability of the reclaimed areas as a whole to transmit water to the groundwater system. The recharge capacity should be restored to support the approved postmining land use and to minimize disturbances to the prevailing hydrologic balance at the mined area and in associated off-site areas. The operator shall be responsible for monitoring according to subsection (9)(C) to ensure operations conform to this requirement.
   2. (B) Groundwater Systems. Backfilled materials shall be placed to minimize adverse effects on groundwater flow and quality, to minimize off-site effects and to support the approved postmining land use. The operator shall be responsible for performing monitoring according to subsection (9)(C) to ensure operations conform to this requirement.
   3. (C) Monitoring. Groundwater levels, infiltration rates, subsurface flow and storage characteristics and the quality of groundwater shall be monitored in a manner approved in the reclamation plan to determine the effects of coal strip mining and reclamation operations on the recharge capacity of reclaimed lands and on the quantity and quality of water in groundwater systems at the mine area and in associated off-site areas. When operations are conducted in a manner that may affect the groundwater system, groundwater levels and groundwater quality shall be periodically monitored using wells of a type and number that can adequately reflect changes in groundwater quantity and quality resulting from those operations. Drilling and development of additional wells if needed to adequately monitor the groundwater system may be required in the reclamation plan. As specified and approved in the reclamation plan, additional hydrologic tests, such as infiltration tests and aquifer tests, must be undertaken by the operator to demonstrate compliance with subsections (9)(A) and (B).
5. (10) Water Rights and Replacement. The operator shall replace the water supply of an owner of interest in real property who obtains all or part of his/her supply of water for domestic, agricultural, industrial or other legitimate use from an underground or surface source where that supply has been affected by contamination, diminution or interruption proximately resulting from surface coal mine operation by the operator.

6. (11) Permanent Impoundments. The operator may construct, if approved in the reclamation plan pursuant to this section and 10 CSR 40- 2.030, permanent water impoundments on mining sites as a part of reclamation activities only when they are adequately demonstrated to be in compliance with 10 CSR 40-2.030 and 10 CSR 40-2.040 in addition to the following requirements:

   1. (A) The size of the impoundment is adequate for its intended purposes;
   2. (B) The impoundment dam construction is designed to achieve necessary stability with an adequate margin of safety compatible with that of structures constructed under P. L. 83- 566 (16 USC 1006);
   3. (C) The quality of the impounded water will be suitable on a permanent basis for its intended use and discharges from the impoundment will not degrade the quality of receiving waters below the water quality standards established pursuant to applicable federal and state law;
   4. (D) The level of water will be reasonably stable;
   5. (E) Final grading will comply with the provisions of 10 CSR 40-2.040 and will provide adequate safety and access for proposed water users; and
   6. (F) Water impoundments will not result in the diminution of the quality or quantity of water used by adjacent or surrounding landowners for agricultural, industrial, recreational or domestic uses.

7. (12) Hydrologic Impact of Roads.

   1. (A) General. Access and haul roads and associated bridges, culverts, ditches and road rights-of-way shall be constructed, maintained and reclaimed to prevent additional contribution of suspended solids to streamflow or to runoff outside the permit area to the extent possible, using the best technology currently available. In no event shall the contributions be in excess of requirements set by applicable state or federal law. All access and haul roads shall be removed and the land affected regraded and revegetated consistent with the requirements of 10 CSR 40-2.040 and 10 CSR 40-2.090, unless retention of a road is approved as part of a postmining land use under 10 CSR 40-2.030 as being necessary to support the post-mining land use or necessary to adequately control erosion and the necessary maintenance is assured.

   2. (B) Construction.

      1. 1. All roads constructed after January

13, 1979, as far as possible, shall be located on ridges or on the available flatter and more stable slopes to minimize erosion. Stream fords are prohibited unless they are specifically approved in the reclamation plan as temporary routes across dry streams that will not adversely affect sedimentation and that will not be used for coal haulage. Other stream crossings shall be made using bridges, culverts or other structures designed and constructed to meet the requirements of this paragraph. Roads shall not be located in active stream channels nor shall they be constructed or maintained in a manner that increases erosion or causes significant sedimentation of flooding. However, nothing in this section will be construed to prohibit relocation of stream channels in accordance with section (5) of this rule.

1. 2. In order to minimize erosion and sub-

sequent disturbances of the hydrologic balance, roads shall be constructed in compliance with the following grade restrictions or other grades determined in the reclamation plan to be necessary to control erosion:

1. A. The overall sustained grade shall

not exceed 1v:10h (10%);

1. B. The maximum grade greater than

ten percent (10%) shall not exceed 1v:6.5h (15%) for more than three hundred feet (300'); and

1. C. There shall not be more than three

hundred feet (300') of grade exceeding ten percent (10%) within each one thousand feet (1000').

1. 3. All access and haul roads shall be

adequately drained using structures such as, but not limited to, ditches, water barriers, cross drains and ditch relief drains. For access and haul roads that are to be maintained for more than one (1) year, water control structures shall be designed with a discharge capacity capable of passing the peak runoff from a ten (10)-year, twenty-four (24)- hour precipitation event. Drainage pipes and culverts shall be constructed to avoid plugging or collapse and erosion at inlets and outlets. Drainage ditches shall be provided at the toe of all cut slopes formed by construction of roads. Trash racks and debris basins shall be installed in the drainage ditches wherever debris from the drainage area could impair the functions of drainage and sediment control structures. Ditch relief and cross drains shall be spaced according to grade. Effluent limitations of section (2) of this rule shall not apply to drainage from access and haul roads located outside the disturbed area as defined in this rule unless otherwise specified in the reclamation plan.

1. 4. Access and haul roads shall be sur-

faced with durable material. Toxicor acidforming substances shall not be used. Vegetation shall be cleared only for the essential width necessary for road and associated ditch construction and to serve traffic needs.

1. (C) Maintenance.

   1. 1. Access and haul roads shall be rou-

tinely maintained by means such as, but not limited to, wetting, scraping or surfacing.

1. 2. Ditches, culverts, drains, trash racks,

debris basins and other structures serving to drain access and haul roads shall not be restricted or blocked in any manner that impedes drainage or adversely affects the intended purpose of the structure.

1. (13) Hydrologic Impacts of Other Transport Facilities. Railroad loops, spurs, sidings and other transport facilities shall be constructed, maintained and reclaimed to control diminution or degradation of water quality and quantity and to prevent additional contributions of suspended solids to streamflow or to runoff outside the permit area to the extent possible, using the best technology currently available. In no event shall contributions be in excess of requirements set by applicable state and federal law. 10 CSR 40-2
2. (14) Discharge of Waters Into Underground Mines. Surface and ground waters shall not be discharged or diverted into underground mine workings.

AUTHORITY: section 444.535.1(5), RSMo 1986.* Original rule filed July 13, 1978, effective Jan. 13, 1979. *Original authority: 444.535, RSMo 1978, amended 1988.