Antidegradation: The Next Big Thing?

April 14, 2004
State and local water resource protection agencies have been through several wash, rinse, and spin cycles over the past few years. The 1990s opened with a flurry of lawsuits aimed at forcing states to develop cleanup plans for polluted waters under the total maximum daily load (TMDL) provisions of the 1972 federal Clean Water Act and its amendments. As the decade progressed, new CWA National Pollutant Discharge Elimination System (NPDES) permit programs for large, medium, and even some small municipal separate storm sewer systems (MS4s) were enacted to deal with stormwater impacts on the nation’s lakes, rivers, streams, wetlands, and oceans. In addition, EPA significantly tightened permit provisions for the largest concentrated animal feeding operations (CAFOs) to reduce pollutant loads from livestock operations.The new millennium therefore opened with a full plate for state and local water resource and stormwater programs, as agency directors scrambled to develop and implement the latest alphabet soup series of programmatic directives. Successfully dealing with TMDLs, NPDES, MS4s, and MEP (maximum extent practicable) best management practices (BMP)s, however, won’t earn program managers a break any time soon–unless they have their antidegradation policies and procedures up to speed.This heretofore somewhat benign area of clean water policy– designed to prevent degradation of surface waters except under certain strictly defined conditions–has been part of federal water policy since the late 1960s. Currently posted at 40 CFR 131.12, the “antideg reg” is surprisingly succinct: It barely fills a half-page in the Code of Federal Regulations. Looks, however, can be deceiving: West Virginia, Pennsylvania, Kentucky, Illinois, Virginia, Georgia, and a smattering of other states across the country have seen actual or threatened legal challenges alleging that their antidegradation programs don’t meet minimum standards. The West Virginia legislature recently adopted a new state rule dealing with antidegradation, and EPA Region 4 is negotiating a proposed program for Kentucky after environmental groups issued a notice of intent to sue because of alleged program inadequacies. In Georgia, a state court upheld an NPDES permit challenge in March 2003 based on the state’s failure to complete an antidegradation review.A Tiered Approach States must have both an antidegradation policy and an implementation procedure. The general federal/state policy is fairly straightforward and seeks to protect surface waters via three tiers. In a practical sense, antidegradation review procedures provide water resource impact benchmarks for activities–such as stormwater and other NPDES permits–that might degrade water quality. The review procedure applies to new or expanded activities conducted under a permit or other regulatory program. The benchmarks are the pollutant loading allowances and required review procedures laid out under the three tiers.Under Tier 1, states must disallow any activity that would cause the loss of existing beneficial uses of the water body under review, which typically translates into violation of numeric or narrative water-quality criteria associated with the designated use of the water body. This is familiar territory: Violation of water-quality criteria is what puts waters on the TMDL list, a requirement under Section 303(d) of the Clean Water Act. Permit writers have traditionally used water-quality-criteria limits when calculating allowable pollutant loadings from new and existing sources, such as wastewater treatment plants, CAFOs, and other discharges.Tier 3 is also a slam dunk in terms of simplicity and familiarity: States must protect specifically identified “outstanding national resource waters,” such as those in federal or state parks or other places where water quality is exceptional or ecologically significant. The challenge comes in working out ways to implement Tier 2 protection in waters with qualities better than the minimum needed to protect existing uses (i.e., water-quality criteria, or the Tier 1 threshold). The federal Tier 2 policy, which has been incorporated into most state antidegradation policies, states:Where the quality of the waters exceed levels necessary to support propagation of fish, shellfish, and wildlife and recreation in and on the water, that quality shall be maintained and protected unless the State finds, after full satisfaction of the intergovernmental coordination and public participation provisions of the State’s continuing planning process, that allowing lower water quality is necessary to accommodate important economic or social development in the area in which the waters are located. In allowing such degradation or lower water quality, the State shall assure water quality adequate to protect existing uses fully. Further, the State shall assure that there shall be achieved the highest statutory and regulatory requirements for all new and existing point sources and all cost-effective and reasonable best management practices for nonpoint source control.
Those three sentences express a fairly simple intent, but developing a program to implement this policy can involve considerable challenges if current permitting only considers water-quality criteria limits (i.e., Tier 1). Regulated activities that might degrade waters protected at the Tier 2 level–which are the vast majority, in most cases–must respond to the following questions:What is the nature of the project; what type of permit or authorization is needed?What pollutants will be discharged; what other impacts are expected?What is the current quality of the receiving water? How will water quality be changed by the proposed activity?How much degradation is allowable before Tier 2 reviews are required?Who determines “important economic or social development,” and how do they do it?What are “cost- effective and reasonable best management practices best management practices for nonpoint source control?”Figure 1 shows an overview of the antidegradation tiers. Note that as pollutant concentrations increase (downward on the left-side vertical axis), water quality decreases. Pristine “outstanding national resource waters” are protected at current Tier 3 quality levels (top), while other clean waters (Tier 2) can be degraded if “important economic and social development” results. No activities are allowed that degrade water quality below the minimum threshold criteria necessary to maintain existing beneficial uses (Tier 1).Assessing Baseline Water Quality and Estimating ImpactsObviously, some sort of assessment of existing or baseline water quality is necessary to determine whether or not a specific project (stormwater discharges, new or expanded wastewater treatment plant, animal feeding operation, etc.) will cause degradation to occur. Establishing baseline water quality, however, can be difficult. States have never had the resources to adequately and completely assess their surface waters and routinely survey fewer than half of their surface waters annually. Another difficult concept to define and operationalize is degradation itself. In the strictest sense, any lowering of water quality can be viewed as degradation, though it is recognized that some minimal level of degradation of even Tier 3 waters occurs whenever humans are active in a watershed. Federal and state agencies have generally defined degradation as consuming a certain portion of the available assimilative capacity (i.e., mixing potential) for a particular pollutant.For example, if the water-quality criteria for a particular pollutant is 10 milligrams per litermg/L and current concentrations of that pollutant in the water body now measures 5 milligrams per liter mg/L (i.e., cleaner than required), specific quantities of that pollutant could be added under Tier 1 until the concentration reached 10 milligrams per liter mg/L. However, Tier 2 protection requires that existing high levels of water quality be “maintained and protected” except under certain conditions. Some states are allowing new activities to consume a certain amount of the available assimilative capacity–5 to 30%–before concluding that an impermissible (Tier 2) amount of degradation has occurred, which triggers requirements for a socioeconomic review to justify the new discharge–and requirements that water-quality criteria not be violated (Tier 1 protection). For outstanding waters protected at the Tier 3 level, states often allow a minimal level of degradation as long as it’s not significant or permanent. Such an approach accommodates the construction of state park facilities, road maintenance, and so on while ensuring that long-term water quality is not affected.Another approach to antidegradation reviews involves a “water body-by-water body” approach for determining degradation. States initially believed that such an approach might be easier to implement, but now seem to be concluding that the water body-by-water body assessment and review procedure might be even more resource intensive than the traditional “pollutant-by-pollutant” approach described above. Although the water body-by-water body approach has not been completely clarified, the environmental community has indicated that quantifying the current and projected future conditions of a water body might require functional analyses of the entire watershed, including sediment transport processes, morphology, hydrology, biota, instream synergistic effects, and other parameters not considered in the pollutant-based approach. Some environmental groups have rejected the water body approach altogether. The Cumberland Chapter (KY) of the Sierra Club, in comments regarding EPA’s proposed antidegradation procedure for Kentucky, called the water body approach “unworkable– both conceptually and pragmatically.”In light of the uncertainties related to the water body-by-water body approach, many states have opted to use the pollutant-based review procedure, which allows assessments to be based only on the pollutants or factors related to the proposed discharge and the receiving waters.Stormwater Permit Program ConsiderationsStormwater permits are NPDES permits by definition. As noted previously, antidegradation reviews generally apply when a regulated entity seeks a permit or other authorization for a new or expanded discharge (i.e., commencement of an activity that may affect water quality). Assessing waters and tracking pollutant impacts to implement antidegradation programs for expanded stormwater discharges can be a resource-intensive pursuit. Several states are now upgrading and integrating their assessment, monitoring, and watershed modeling capabilities to implement antidegradation programs as part of their permitting and water-quality certification programs.For stormwater permits, states are moving to adopt antidegradation review procedures that allow permittees to forego rigorous pollutant-mixing analyses if activities are conducted under a general permit and follow a carefully prescribed and enforced menu of best management practices BMPs. BMPs–designed to reduce or eliminate adverse water-quality impacts from sediment, nutrients, bacteria, and other pollutants–can include erosion and sediment controls at new construction sites, upgraded septic systems, control of impervious surface runoff, and tighter overall soil and water conservation practices. In a recent decision on West Virginia’s antidegradation procedure, a federal court indicated that the BMP approach might be an acceptable way to implement antidegradation policies under general permit programs if the BMPs prevent degradation of water quality.However, environmental groups have indicated that if stormwater discharges significantly degrade water quality — such as in areas of new development — or if they cause violations of water-quality criteria, these groups will challenge activities proposed under stormwater permits by focusing on both antidegradation and TMDL issues. Given the recent federal court rulings on antidegradation, which support fairly narrow interpretations of the federal regulation, the incentive to ensure that new or expanded stormwater discharges do not adversely impact water quality has never been greater.What’s Next?States are slowly working through their policies, making upgrades, and developing implementation procedures where needed. Real or possible legal action has prompted Nevada, Colorado, Oregon, Washington, West Virginia, Pennsylvania, Arizona, Montana, Kentucky, and a handful of other states to deal with a number of wide-ranging issues in their program upgrades. States have also sought ways to enhance their antidegradation programs to further protect water quality.For example, several states maintain a “Tier 2.5” classification that protects relatively pristine waters that don’t qualify for the Tier 3 designation. While property owners in some Tier 2.5 watersheds have expressed concern that the “two-point-five” protective measures will prevent development of their property, others assert that the measures will help regional tourism and, recreation, boost property values, and preserve dwindling high-quality water resources. Sorting through such arguments is difficult, but a number of studies have confirmed that proximity to high-quality water resources increases land worth overall.Other issues vexing state officials relate to the sheer amount of work required to assess existing water quality, estimate impacts of a proposed new or expanded regulated activity, and then check up to see what really happens after the permit is issued and the activity commences. Some states are opting to share the monitoring burden with the regulated community, which is being required to shoulder additional environmental assessment and monitoring responsibilities for other programs as well. Some businesses have expanded their environmental impacts/analyses activities as part of internal efforts to initiate or maintain ISO 14000 environmental management systems (EMS), but for others the ongoing assessments are simply another transaction expense, another cost of doing business.
Ideally, the assessment and monitoring information collected by public agencies, private businesses, and trained environmental group members would be quality-controlled and fed into a system capable of generating watershed profiles and dynamic models that could be used to predict impacts under various scenarios. State and EPA water agency managers are pursuing such a system as part of a possible watershed-based NPDES permitting system, but tight budgets and poor integration among data collectors have kept progress somewhat measured. Many states are barely able to monitor and assess a third of their waters under current budget restraints, and relief seems distant at best.
One thing is certain, however: Antidegradation is not going away. The federal rules predate the Clean Water Act, and recent case law in US courts clearly indicates that the new focus on this old part of clean water law will remain on the radar screens of state water agency staffs for several years to come.

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