Total Maximum Daily Loads and Anti-degradation

The Clean Water Act of 1972, administered by the U.S. Environmental Protection Agency (EPA), established a program in section 402 to regulate the discharge of pollutants into the nation’s rivers, streams, and lakes. This program, the National Pollutant Discharge Elimination System (NPDES), is exactly what its name implies: a system to eliminate pollutants from being discharged into waters of the U.S. Any organization, company, or person (entity) discharging water into a receiving body of water in the U.S. must apply for and receive an NPDES permit.

Almost all NPDES permits contain standards or limits to the amount of pollutant that can be discharged by assigning an upper level concentration of the pollutant in the discharge water. The effluent limits for mining NPDES permits can be assigned in three ways: 1) technology-based, 2) water quality-based, and 3) best professional judgment.

Many coal entities were given technology-based limits in their NPDES permits, and these limits gave numeric concentration values that the discharged water must meet. For technology-based limits, the discharge water must have:

For example, if the average monthly concentration of analyzed water samples is found to exceed 3.0 mg/L of iron, then the operator of the facility is in violation of the NPDES permit and the violator is subject to penalty.

Some entities that apply for NPDES permits to discharge water may not be given technology-based limits but may be given stricter water quality-based limits. Each state is authorized by the Clean Water Act to assign streams, rivers, and lakes into water use categories. For each water use category, the state must establish numeric criteria or narrative statements known as "water quality standards" to protect the designated water use category.

Under the water quality standards, streams and rivers may be assigned into one of five water use categories and further into subcategories:

Category A – Public Water Supply
Category B - Propagation and Maintenance of Fish and Other Aquatic Life

B1- Warmwater Fishery
B2 - Trout Waters
B4 - Wetlands

Category C - Water Contact Recreation

Category D - Agriculture and Wildlife Use

D1 - Irrigation

D2 - Livestock Watering

D3 - Wildlife

Category E - Industrial Water Supply, Water Transport, Cooling and Power

E1 - Water Transport

E2 - Cooling Water

E3 - Power Production

E4 - Industrial

For each of these categories and some subcategories, specific water quality criteria dictate the effluent concentrations that can be discharged into these designated streams to protect the numeric criteria. Category A streams (public drinking water supplies) have concentration limits on many variables such as ammonia, arsenic, copper, chromium, iron, lead, manganese, nickel, selenium, zinc, and fecal coliforms (and others that are not listed here). Category B1 streams have limits on similar variables as Category A streams, but sometimes the concentration limits are slightly different, which could allow a slightly higher or lower amount of pollutant to be discharged into a stream assigned to that water use category. Therefore, each water use category has a set of specific numerical criteria or narrative statements to protect the uses of that stream. A water quality-based NPDES Permit will set the effluent limits to ensure that the discharges will not violate the stream’s numeric criteria for that use.

For instance, the numeric criteria for iron for a warm water fishery is 1.5 mg/L. Therefore, effluent limits would have to be set at discharge outlets so that the iron concentration does not exceed 1.5 mg/L in the stream. In this example, a water quality-based limit (based on the water quality standard for the receiving stream’s designated water use) is given when the technology-based limit may not keep the iron in the stream less than 1.5 mg/L.

A listing of streams and rivers in the state along with their designated stream use and numerical criteria may be found in the Water Quality Standard Regulations, which are promulgated by the West Virginia Environmental Quality Board. Copies can be obtained from the West Virginia Secretary of State’s Office or you can visit the Secretary of State’s web site (http://129.71.220.230/csr). Click on search, search for rules, then type in water.

A third way of assigning effluent limits for an NPDES permit is by Best Professional Judgment (BPJ). In order to establish a BPJ effluent limit, an economic evaluation of treatment technologies must be done. The treatment technology deemed economically achievable could be used, and the effluent discharged from such a treatment technology could be the applicable BPJ effluent limit in the NPDES permit. This type of effluent limit assignment is seldom used, but is used for NPDES remining permits.

The Clean Water Act of 1972, in section 303(d), required each state to develop a list of impaired streams, rivers, and lakes. These impaired waters do not currently meet the water quality standards that the state has set for them based on their designated water use category, even after point sources of pollution have been controlled and pollution control technologies have been installed under the NPDES program. Therefore, these impaired streams must have further reductions in pollutant loads in order to meet the water quality standards for streams in that category. In other words, the technology-based limits initially assigned to the point discharges and the accumulation of pollutants from other non-point discharges still do not protect the stream quality for its designated use. A Total Maximum Daily Load (TMDL) determines a maximum amount of pollutant which is allowed in an impaired stream and can be viewed as a pollution reduction plan to help the stream attain the desired water quality standards.

In West Virginia, the list of impaired streams is called the 303(d) list, and this list is updated every two years. The 1998 303(d) list is currently in effect and a revised list will be released in April 2002. The requirement to develop a 2000 list was suspended by EPA. There are about 700 streams in West Virginia on the 1998 303(d) list. If a stream is impaired and therefore does not meet the water quality numerical criteria for its designated water use category, then a TMDL will be developed and assigned for pollutants that exceed the numerical criteria. Since there are so many streams on the 303(d) list, the law requires that states establish a schedule to ensure that TMDLs are completed in a timely manner.

A TMDL is a load limit or a maximum amount of pollutant that a waterbody can receive and still meet water quality standards. It allocates pollutant loads among point and non-point pollution sources and includes a margin of safety to address uncertainty. The general philosophy of the WVDEP TMDL program is to identify the primary sources of pollution in impaired streams and to target reductions to those pollution sources. For streams impaired by mining, the philosophy is to develop a TMDL that reduces pollutant loads from non-point sources first (abandoned mine lands and bond forfeiture sources), then to reduce the pollutant amounts from permitted point sources. The amount of pollutant in a TMDL is given in load units such as pounds per day or pounds per year. This TMDL pollutant amount is then converted into a concentration-based waste load allocation for implementation in NPDES permits.

It is probable that some permitted point sources with current technology-based limits will be given lower effluent limit concentrations (more stringent) under TMDL. For example, some renewed NPDES permits will probably receive an iron waste load allocation effluent limit of some value between 0.5 and 3.2 mg/L, whereas before the effluent limit concentration was 3.0 mg/L under technology-based limits. For manganese, the limit may be changed from 2.0 mg/L to some value between 1.0 and 2.0 mg/L. Aluminum is not currently regulated under technology-based limits, but under the new TMDL waste load allocation, an aluminum effluent limit concentration will be assigned and will probably be some value between 0.75 and 4.3 mg/L. Other parameters may also be assigned based on the water use category of the stream.

In summary, the Clean Water Act established the NPDES program to regulate discharges into waters of the U.S. The Act also required each state to designate their streams into water use categories and then for each state to establish water quality standards to maintain those intended uses. The NPDES permits set effluent limits at the highest concentration of pollutant that could be in the discharge water in order to protect the uses of that waterbody. The TMDL program helps the NPDES program to further reduce the pollution in streams that do not meet water quality standards by assigning a pollutant load to the stream. Both non-point and point sources are evaluated to determine their input and cumulative impact on the total pollutant load.

In addition to the NPDES program and TMDL development, another water quality improvement program is being implemented to further execute the mandate in the Clean Water Act "to eliminate the discharge of pollutants into waters of the U.S." As another level of review and protection in the NPDES program, the Clean Water Act also mandated that each state develop an anti-degradation policy to further protect stream, river, lake, and wetland water quality.

Over the past two years in West Virginia, much effort and disagreement has gone into the establishment of an anti-degradation implementation rule. West Virginia has had an anti-degradation policy since the early 1980's, but no guidelines were available to implement the policy.

Through months of negotiations and compromises, a group of lawmakers, environmentalists, industry representatives, landowners, and state government personnel worked to develop an implementation rule for anti-degradation. The 2001 West Virginia Legislature approved a process to ensure that the state's high quality waters were given special protection and that all other waters in the state would be protected to maintain their designated or, at a minimum, their existing uses.

The anti-degradation rule gives four levels of protection for West Virginia waters: Tiers 1, 2, 2.5, and 3. Tier 3 protection is the highest level of protection and it is applied to "Outstanding National Resource Waters." Such waters are those within West Virginia wilderness areas, which include Dolly Sods, Laurel Fork, Otter Creek, and Cranberry. Tier 3 protected waters cannot be degraded.

Tier 2.5 protection will be given to waters of special concern. A presumptive list of Tier 2.5 protected waters in West Virginia includes 444 streams covering over 2,000 miles. Tier 2.5 protected waters are designated as naturally-reproducing trout streams and other streams that WVDEP has determined to be reference streams with a high biological and aquatic life score. No significant degradation of a Tier 2.5 protected stream will be allowed. Significant degradation is defined as reducing the assimilative capacity of the receiving water by more that 10 percent. New or expanded NPDES permits that discharge into a Tier 2.5 protected stream may be given more stringent water quality-based effluent limits so that no significant degradation of the stream will occur. Public comment will be allowed for those streams that are being considered for the Tier 2.5 protection list.

Tier 2 protection is the default or standard level of protection. These are high quality waters that meet or have better water quality than the water quality standards established for that stream. The intended uses of these waters must be protected and degradation can be allowed up to the numeric criteria for that water use category. However, any significant degradation (>10% of remaining assimilative capacity) of a Tier 2 protected water must undergo an alternatives analysis and socio-economic review before the degradation activity could be approved.

Tier 1 protection requires that existing uses of the water shall be maintained and protected. This level of protection will be applied at a minimum to all West Virginia waters. Two streams in the state, namely the main stems of the Monongahela and Lower Kanawha Rivers, have been designated as only Tier 1 protected waters for all pollutants. However, this protection level may also be assigned later on a pollutant by pollutant basis to other streams that do not currently meet water quality standards. Discharges into Tier 1 protected waters will have water quality-based effluent limits for the pollutants that exceed water quality standards.

New or expanded activities (discharges) will have to undergo an anti-degradation review. The question that will be asked for any new or expanded activity that will discharge water into a stream is "will the proposed activity significantly degrade the water segment." If the answer is yes, then an anti-degradation review must be performed. Existing facilities will have their current effluent limits reviewed when the NPDES permit is renewed, and the effluent limits in the renewed permit may be altered if the original limits are not protective of the stream’s use.

Implementation of TMDLs and the guidance for anti-degradation implementation are being formulated currently. Public meetings, brochures, and Internet information will be made available from WVDEP to help interested and affected parties understand the process.

The next Green Lands article will address the information that is necessary for TMDL development and some examples of effluent limits for point discharges in streams which were assigned TMDLs. In conjunction with WVDEP officials, the article will address information needed for baseline water quality assessments and the review procedures that will allow the establishment of anti-degradation effluent limits. A comparison of effluent limits before and after TMDL implementation and anti-degradation application will also be shown.

The author thanks Pat Campbell, Larry Emerson, Ron Hamric, Louis McDonald, Dave Montali, Ken Politan, and John Sencindiver for reviewing the material and making helpful suggestions.

Burns, D. 2001. The antidegradation policy in West Virginia: impacts on the coal industry. In: West Virginia
         Surface Mine Drainage Task Force Symposium, April 2-3, 2001, Morgantown, WV.
U.S. Environmental Protection Agency. 2001. Antidegradation: role of economic analysis. U.S. EPA website:
         http://www.epa.gov/OST/econ/
U.S. Environmental Protection Agency. 2002. NPDES permit program - general information. U.S. EPA website:
         http://www.epa.gov/owm/gen2/
U.S. Environmental Protection Agency. 2002. Overview of current total maximum daily load - TMDL - program
         and regulations. U.S. EPA website: http://www.epa.gov/owow/tmdl/overviewfs/
West Virginia Department of Environmental Protection. 2001. Baseline water quality (BWQ) assessment
         procedures. Antidegradation guidance document, WVDEP, Charleston, WV.
West Virginia Department of Environmental Protection. 2002. Total maximum daily load. WVDEP website:
         http://www.dep.state.wv.us/   
Yaussy, D. 2001. Antidegradation implementation procedures adopted by the 2001 West Virginia legislature.
         Unpublished summary, Robinson & McElwee, PLLC, Charleston, WV.

Picture 1. Acid water from an abandoned underground mine is being discharged from this point source into a major stream. For streams like this one that cannot meet the water quality standards, TMDLs will be developed in order to reduce the pollutant load in the stream. A large acid mine drainage chemical plant is being designed to treat the water and reduce the pollutant load to the stream.