How can Section 319 of the Clean Water Act do more to address nonpoint source pollution?

by Sarah Bailey

The EPA established the Clean Water Act in 1972 to address the variety of pollutants in our national waters. Today, the largest pollutants in our waterways are nonpoint source pollutants, which come from overland flow and runoff that transports sediments, chemicals, oils, and excess nutrients from fertilizers into streams, rivers, and lakes[1]. In 1987, Section 319 of the Clean Water Act (CWA) was passed to allocate funding for projects that address nonpoint source pollutants like these[2]. Each year, Congress has the power to allocate varying amounts towards these programs, but in recent years those funds have been around $200 million[3]. Through Section 303(d), states are required to set total maximum daily load (TMDL) requirements and sample waterways to identify impaired water bodies, but they aren’t required by the CWA to enforce those TMDLs[4]. Section 319 requires states to set up NPS pollution management strategies with specific goals for reducing NPS pollution to then be eligible to apply for the grant money to fund those goals[5]. This combination of varying scientific literature on the success of Section 319 funding, the lack of consistent and widespread measurement of water quality across states, and the bureaucracy of the EPA in helping regional agency’s fund successful projects indicates that more specific analyses and policies should be put into place to effectively measure and limit NPS pollution rather than allowing voluntary actions from states guided by Section 319 of CWA to dominate pollution controls. As an alternative, Section 319 funds should be used to mandate local agencies to implement economic incentives through input- and technology-based policies rather than voluntary programs to reduce NPS.

Section 319 provides states flexibility and power to create and enforce the standards and projects that are best for them, allowing local environmental knowledge to guide strategies. One downside of this policy is the lack of incentives to reach more ambitious water quality standards that could be more costly. Depending on the scale used to evaluate this policy impacts how successful Section 319 has been. The EPA sites almost 800 success stories of programs that led to restoration at individual water bodies[6]. But, because of states’ power to decide what standards they set, many states do not have total nitrogen or total phosphorous criteria for any water bodies, making regulations and measurements of pollutant changes more difficult[7]. However, a study by Tomczyk et al. from the University of Georgia has demonstrated no correlation between the amount of funding a state receives from the EPA and a decrease in phosphorous and nitrogen pollution at the state scale[8]. Some of the states may have a harder time implementing policies and pollution reduction programs because of lower levels of staffing and organizational support from their state[9].

While the voluntary and incentive-based regulation from Section 319 allows states to experiment with different projects that are more appropriate to their economies and climatology, the policy is not directly leading to the intended consequences at least in the short term[10]. A study by Ilampooranan et al. found that there may be a significant lag time between when NPS pollution reduction strategies are implemented and when the benefits are realized because of the persistence of excess nutrients in the soil from previous release of fertilizer[11]. This could indicate that the measuring of pollutants and goals of the NPS projects should be aimed at long-term reduction of fertilizer application or pollution infiltration into the ground as well as means to remove lingering nutrients in soil and groundwater. 

Another likely cause of lagging changes in pollution estimates is the use of 319 funds for indirect rather than direct approaches to pollution mitigation[12]. Using educational tools is absolutely an important part of reducing unintentional runoff in agriculture and urban settings, but having more funds going to wetland creation and projects that can prevent excess nutrients from reaching water bodies would lead to faster changes in quantitative results. The Government Accountability Office (GAO) recommended in May 2012 that the EPA provide better guidelines for regional EPA offices for evaluating project proposals in a way that would better select projects with a more direct impact[13]. However, the EPA took several years to implement those changes, and there remains a large portion of rivers and lakes in the United States that have yet to meet water quality standards, specifically because of lack of enforcement around NPS pollution[14]. Of the impaired water bodies, currently about 50% have been identified as impaired because of NPS pollution[15].

Literature indicates that regulations around water pollutants, including NPS pollutants, are often inefficient and have a smaller benefit-to-cost ratio than would indicate that the regulation should be in place[16]. Compared to results from the cap-and-trade programs that dominate air pollution engineering, the command-and-control regulations that mitigate water pollutants seem to be performing much worse[17]. To reform these regulations, two possible options are to adopt performance-based and design-based initiatives. Due to the limitations of measuring NPS pollution, performance-based regulations are a lot more complicated to implement, especially on a federal level[18]. While design-based initiatives still need to be implemented on a local level, the money currently being used for voluntary action from Section 319 could be shifted to fund primarily or exclusively design-based initiatives. Counties or a regional jurisdiction would be required to determine whether NPS pollution is correlated with land use activities in their area, and if it is, they would be mandated to provide a regulation for their area that uses design-based initiatives and could then apply for Section 319 to implement them. This would provide local flexibility with input- and technology-based incentives dependent upon the specific economic and political conditions of the area[19]. Examples would be using taxes on fertilizer purchases, lump sum subsidies to stop farming on extramarginal land, or mandating uniform adoption of nitrogen inhibitors depending on where the most NPS pollution is coming from in that state[20]. The USDA found that these programs were the most cost-efficient way to address NPS pollution with the least administrative burden[21]. Reforming Section 319 while retaining local involvement and expertise can catalyze the funds already available into a more efficient decrease in NPS pollution. With more cost-efficient policies, communities can care for their waterways without causing excessive economic burden. 

[1] “Basic Information about Nonpoint Source (NPS) Pollution,” United States Environmental Protection Agency, Last updated on December 4, 2023,

[2] “319 Grant Program for States and Territories,” United States Environmental Protection Agency, Last updated on July 17, 2023,

[3] Nathan Tomczyk et al. “Nonpoint source pollution measures in the Clean Water Act have no detectable impact on decadal trends in nutrient concentrations in U.S. inland waters,” Ambio 52, (2023): 1475 – 1487, doi: 10.1007/s13280-023-01869-6.

[4] Tomczyk et al., “Nonpoint source pollution.”

[5] Catherine Janasie, “The Management of Nonpoint Source Pollution under the Clean Water Act,” June 2018,

[6] “Polluted Runoff: Nonpoint Source Pollution: Success Stories Search Results,” United States Environmental Protection Agency, Last updated on February 8, 2017,

[7] “State Progress Toward Adopting Numeric Nutrient Water Quality Criteria for Nitrogen and Phosphorus,” United States Environmental Protection Agency, Last updated on January 23, 2024,

[8] Tomczyk et al., “Nonpoint source pollution.”

[9] Tomczyk et al., “Nonpoint source pollution.”

[10] “Watershed Academy Web: Section 319: Nonpoint Source Program,” United States Environmental Protection Agency, accessed February 9, 2024, 

[11] Idhayachandhiran Ilampooranan et al, “A Race Against Time: Modeling Time Lags in Watershed Response,” Water Resources Research 55, no. 5 (2019): 3941-3959, doi: 10.1029/2018WR023815. 

[12] “Environmental Protection Agency: Status of Efforts to Address Nonpoint Source Water Pollution through the Section 319 Program,” United States Government Accountability Office, July 14, 2016,

[13] “Environmental Protection Agency: Status of Efforts to Address Nonpoint Source Water Pollution.”

[14] “Environmental Protection Agency: Status of Efforts to Address Nonpoint Source Water Pollution.”

[15] “National Nonpoint Source Program —a catalyst for water quality improvements,” United States Environmental Protection Agency, October 2016,

[16] David A. Keiser, “The low but uncertain measured benefits of US water quality policy,” PNAS 116, no. 12 (2019): 5262–5269, doi: 10.1073/pnas.1802870115.

[17] Keiser, “The low but uncertain measured benefits.”

[18] Ken Bao, “Command-Control Versus Market Incentive Policies for Non-point Source Pollution,” SSRN (2022), doi: 10.2139/ssrn.4168357.

[19] Marc Ribaudo, Richard Horan, and Mark Smith, “Economics of Water Quality Protection From Nonpoint Sources: Theory and Practice,” Economic Research Service, US Department of Agriculture, November 30, 1999, 

[20] Ribaudo, “Economics of Water Quality Protection.”; Winston Harrington, Alan J. Krupnick and Henry M. Peskin, “Policies for nonpoint-source water pollution control,” Journal of Soil and Water Conservation 40, no.1 (1985): 27-32.

[21] Ribaudo, “Economics of Water Quality Protection.”

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