Clean Water Act Research Articles

Does institutional location matter? The effect of agency type on resource distribution for nonpoint water pollution

ABSTRACT With the rejuvenated emphasis on nonpoint pollution under the Water Quality Act (WQA) of 1987, states seek ways to address nonpoint pollution sources. States can use Clean Water State Revolving Funds (CWSRF) to address nonpoint needs; these funds are administered by state agencies, and funding decisions are typically made by agency personnel. While some states have aggressively funded nonpoint projects, other states have been much more reticent. Moreover, states have created different administrative structures to administer these funds. Does the nature of the structure impact the distribution of loans? Utilizing a dataset spanning state-level data from 1988 to 2016, we test a novel negative binomial cross-sectional time-series model employing the number of CWSRF loans directed to nonpoint projects as the dependent variable. We find that states where water quality management is buried within a ‘mini-EPA’ agency are the least likely to allocate CWSRF loans for nonpoint source issues, whereas states with ‘super’ agencies or combined environmental/health agencies allocate a higher number of CWSRF loans to nonpoint source projects.

Explaining state efforts to create Total Maximum Daily Load (TMDL) agreements

AbstractObjectivesWith the rejuvenated emphasis on nonpoint pollution under the Water Quality Act (WQA) of 1987, Environmental Protection Agency (EPA) began to face an onslaught of lawsuits designed to pressure the EPA to enforce the requirements of Section 319 of the WQA to address nonpoint pollution. Known as Total Maximum Daily Load (TMDL) agreements, the purpose of these plans was to limit the amount of polluted runoff reaching a state's waterways. While some states took a proactive stance on these plans, other states resisted the implementation of Section 319. This article seeks to understand state choices in the development and implementation of TMDL agreements.MethodsUtilizing a data set spanning state‐level data from 2000 to 2020, we test a novel cross‐sectional time series model employing the number agreements entered into by a state as the dependent variable.ResultsWe find that both political and need explanations are generally supported, while policy need explanations are somewhat more promising.ConclusionsTaken together, the models offer several insights into state choices around TMDL creation. The political model is the weakest, suggesting that TMDLs are not overtly political. Policy needs seem to play a more critical role in the preponderance of TMDL agreements than partisan politics.

Benchmarking produced water treatment strategies for non-toxic effluents: Integrating thermal distillation with granular activated carbon and zeolite post-treatment

The management of produced water (PW) generated during oil and gas operations requires effective treatment and comprehensive chemical and toxicological assessment to reduce the environmental risks associated with reuse or discharge. This study evaluated a treatment train that included a low-temperature thermal distillation pilot system followed by granular activated carbon (GAC) and zeolite post-treatment for processing hypersaline Permian Basin PW. Our study provides a unique and comprehensive assessment of the treatment efficiency considering a targeted chemical scheme together with whole effluent toxicity (WET) tests across four trophic levels regarding aquatic critical receptors of concern (ROC): Raphidocelis subcapitata, Vibrio fischeri, Ceriodaphnia dubia, and Danio rerio. The distillate from the thermal distillation process met various numeric discharge standards for salinity and major ions. However, it did not meet toxicity requirements established by the United States National Pollutant Discharge Elimination System program. Subsequent post-treatment using GAC and zeolite reduced the concentration of potential stressors, including volatile organics, NH3, Cd, Cr, Zn, and Mn in the final effluent to below detection limits. This resulted in a consistent toxicity reduction across all WET tests, with no observable adverse effects for R. subcapitata, C. dubia, and D. rerio (no observed effect concentration >100%), and V. fischeri effects reduced to 19%. This study realizes the feasibility of treating PW to non-toxic levels and meeting reuse and discharge requirements. It underscores the importance of implementing integrated treatment trains to remove the contaminants of concern and provides a systematic decision framework to predict and monitor environmental risks associated with PW reuse.

River Communities, Disaster Science, and the Politics of Water Safety: Understanding Water Quality Debates in the Aftermath of the Gold King Mine Spill

ABSTRACT After environmental disasters, scientific claims about environmental risk face a paradox. Impacted communities turn to scientific bodies for safety information, yet scientific findings are often challenged publicly in post-disaster debates. This study explores this paradox after the 2015 Gold King Mine spill in the Animas River, USA. We ask how a river is declared “safe” after such a disaster, by whom, and based on what metrics. We examine how scientific claims about water safety were debated in newspapers in three locations: Silverton and Durango, Colorado, and the Navajo Nation. Drawing on Cash et al.’s [Knowledge systems for sustainable development. Proceedings of the National Academy of Sciences, 100(14), 8086–8091. https://do.org/10.1073/pnas.1231332100] key features of science for public decision-making, we find that local debates hinged on issues of salience, credibility, and legitimacy, but these criteria varied in importance across locations. We also argue that these criteria do not sufficiently explain river safety debates. Attention to regulatory and scientific standards used to interpret river safety is necessary for understanding spill responses. Clean Water Act (CWA) standards sidelined public concerns about waterways that fell outside CWA benchmarks. This study highlights the importance of scrutinizing the standards used to deem environments “safe” when producing and communicating disaster science. Key policy highlights Scientific communication after an environmental disaster should be salient, credible, and legitimate. In addition, the scientific and regulatory standards used to deem post-disaster environments “safe” must be scrutinized and their limitations acknowledged. Acknowledging and addressing community-specific concerns and histories – especially those of indigenous communities – is vital in disaster-recovery communication.

Quantifying water effluent violations and enforcement impacts using causal AI

AbstractIn the landscape of environmental governance, controlling water pollution through the regulation of point sources is vital as it preserves ecosystems, protects human health, ensures legal compliance, and fulfills global environmental responsibilities. Under the Clean Water Act, the integrated compliance information system monitors the compliance and enforcement status of facilities regulated by the National Pollutant Discharge Elimination System (NPDES) permit program. This study assesses temporal and geographic trends for effluent violations within the United States and introduces a novel metric for quantifying violation trends at the facility level. Furthermore, we utilize a linear parametric approach for Conditional Average Treatment Effect (CATE) causal analysis to quantify the heterogeneous effects of EPA and state enforcement actions on effluent violation trends at facilities with NPDES permits. Our research reveals insights into national pollutant discharge trends, regional clustering of all pollutant violation types in Ohio ( Z‐score of 2.15), and priority pollutants in West Virginia ( Z‐score of 3.07). The trend metric identifies regulated facilities that struggle with severe and recurring violations. The causal model highlights variations in state compliance and enforcement effectiveness, underscoring the successful moderation of violation trends by states such as Montana and Maryland, among others.

Determining the connectivity of tribal communities to wastewater treatment facilities for use in environmental contamination and exposure assessments by wastewater-based surveillance.

Limited information is available on the connectivity of Tribal communities to wastewater treatment facilities (WWTFs). This is important for understanding current sanitation infrastructure which drives public health and community construction, knowledge of potential routes of exposure through lack of infrastructure and/or discharging facilities, and opportunities to assess community health through wastewater-based surveillance (WBS). The objective of this work was to assess current wastewater infrastructure for 574 Federally Recognized Indian Tribes (FRITs) in the United States (US) to determine the number and location of facilities on or adjacent to Tribal reservations and Off-Reservation Trust Lands, with the goal of determining the feasibility of employing wastewater-based surveillance within these communities and to identify areas with inadequate sanitation infrastructure. Here, we identified available National Pollutant Discharge Elimination System (NPDES) wastewater discharge permits in the Environmental Protection Agency's Environmental Compliance History Online database to assess proximity to and within spatial boundaries of Tribal lands. These data were coupled to race data and tribal spatial boundary information from the US Census Bureau. 94 FRITs have registered NPDES permits within Tribal boundaries including a total of 522 facilities. 210 of these are American Indian (AI)-serving (>50% AI) with the ability to reach 135,000 AI-people through the wastewater network to provide community health assessments via WBS. Of the remaining facilities, 153 predominantly serve non-Tribal populations raising concerns about infrastructure placement and indigenous sovereignty. 523 FRITs were identified as without permitted discharging WWTFs, which may suggest inadequate or alternative infrastructure. Here, multiple data sources including permit information from the Environmental Protection Agency's National Pollution Discharge Elimination System and US Census Bureau data were used to determine the number of wastewater treatment facilities on or adjacent to Tribal lands and how many community members were connected to those municipal systems. This information was used to assess which Tribal communities may be a viable option for wastewater public health surveillance techniques and were used to answer supplemental questions related to basic sanitation and environmental justice concerns.

Pollution-induced regulation substitution

This paper estimates the previously unexamined effect of Clean Air Act (CAA) monitoring and enforcement (M&E) on Clean Water Act (CWA) M&E. According to the literature, air polluters located close to violating air monitors face more CAA scrutiny, as regulators reallocate resources to these areas. Given limited regulatory resources within states, we examine how this reallocation affects CWA M&E. We find that plants located close to violating particulate matter (PM) monitors are less likely to receive state-level CWA inspections and enforcement actions. These results provide evidence that state regulators substitute resources across federal environmental regulations, which may explain previously observed substitution of pollution across media from air to water as a response to heightened CAA scrutiny.

Contemplation of Improvement Efforts to Manage Combined Sewer Overflows

Combined sewer overflow (CSO) is a significant environmental concern and public health risk (e.g., water contamination, eutrophication, and beach closure). The Environmental Protection Agency (EPA) has introduced the National Pollutant Discharge Elimination System (NPDES) permitting program to regulate and address this matter. This program mandates the control of CSOs for more than 700 municipalities obligated to devise Long-term Control Plans (LTCPs) to curb combined sewer overflows and reduce them to safe levels. The LTCP involves diverse strategies, including sewer separation, green infrastructure improvements, and conventional gray infrastructure upgrades. This study investigates several municipalities’ solutions for CSO problems that use conventional methods and wireless sensor technology as real-time control, mainly focusing on a comparative analysis of two cities, Richmond, Virginia, and South Bend, Indiana, such as their average rainfall, the frequency of overflows, and the capacity of treatment plants. The findings indicate that integrating sensor technology could significantly enhance modeling endeavors, bolster the capacity of existing structures, and substantially enhance preparedness for storm events. The EPA’s Storm Water Management Modeling (SWMM) software is utilized. Through an analysis of SWMM data, the study suggests the potential for leveraging wireless sensor technology to achieve more robust control over CSOs and significant cost savings as a part of LTCPs.

Cleaner waters and urbanization

The Clean Water Act (CWA) addresses nonpoint source pollution primarily by funding public works projects. Our study evaluates changes in rural watersheds before and after CWA projects are implemented, compared to watersheds without funding. We find that projects significantly reduce water pollution, with corresponding increases in human population and residential construction. Using housing values, we estimate that economic benefits exceed government costs by at least fourfold. Over half of this benefit is attributable to new housing. Our findings show that pollution can impede urbanization, suggesting more broadly that residential development is an important mechanism of revealed preference for environmental quality.

Evaluating Clean Water Act progress drivers for Idaho rivers and streams 2002–2022

In the United States, the Clean Water Act (CWA) is the primary legislation driving surface water quality management. Its goal is to “restore and maintain the chemical, physical, and biological integrity of the Nation’s waters.” Section 305(b) of the CWA requires states to document CWA progress by reporting whether applicable water quality standards are achieved for all state waters every two years. Developing strategies for increasing the proportion of waters achieving standards requires diagnosing factors driving 305(b) data temporal trends. This analysis demonstrates how systematically analyzing 305(b) data in new ways can help document CWA progress (or lack thereof) and associated drivers. Idaho 305(b) data were used to evaluate the relative contribution of assessment progress and restoration to 2002–2022 Idaho 305(b) temporal trends. Assessment progress was defined as assessing unassessed waters and correcting assessment errors. Restoration was defined as changes from not achieving one or more standards to achieving all assessed standards because water quality improved. From 2002–2022, the percentage of Idaho stream kilometers achieving all assessed standards increased from 24% to 32%. Systematically evaluating reasons for stream status changes revealed this trend was driven primarily by assessment progress, specifically progress monitoring previously unassessed waters in good condition and correcting prior assessment errors. More stream km changed from impaired to unimpaired because prior assessment errors were corrected than because water quality improved. In each biennial 305(b) report ≤ 5% of all stream km changing status resulted from water quality improvement. As of 2022, more state stream km were impaired (39%) than unassessed (29%) and restoration success rates will likely become the primary driver of 305(b) temporal trends in the future. Systematically analyzing 305(b) data in new ways may help develop new empirically driven strategies for accelerating CWA progress and merits further investigation.

Nonpoint source pollution measures in the Clean Water Act have no detectable impact on decadal trends in nutrient concentrations in U.S. inland waters.

The Clean Water Act (CWA) of 1972 regulates water quality in U.S. inland waters under a system of cooperative federalism in which states are delegated implementation and enforcement authority of CWA provisions by the U.S. Environmental Protection Agency. We leveraged heterogeneity in state implementation of the CWA to evaluate the efficacy of its nonpoint source provisions in reducing nutrient pollution, the leading cause of water quality impairment in U.S. inland waters. We used national survey data to estimate changes in nutrient concentrations over a decade and evaluated the effect of state-level policy implementation. We found no evidence to support an effect of (i) grant spending on nonpoint source pollution remediation, (ii) nutrient criteria development, or (iii) water quality monitoring intensity on 10-year trends in nutrient concentrations. These results suggest that the current federal policy paradigm for improving water quality is not creating desired outcomes.

Progression of river BOD/DO modeling for water quality management

A historical perspective of river BOD/DO modeling using the Streeter-Phelps equation in the past century is presented with cases in the United States, Taiwan, and India. The main emphasis is on the regulatory aspects of modeling during the five decades following the passage of the 1972 Clean Water Act (CWA) in the United States. Success of the CWA in river clean-up is demonstrated via BOD/DO modeling for management use. Continuing interests outside the United States in anaerobic rivers and eutrophication-related low dissolved oxygen problems are serving as new proving ground for applications of river BOD/DO modeling. In addition, road blocks on BOD/DO modeling under future conditions for water quality management are outlined. PRACTITIONER POINTS: Water quality-based control to set end-of-pipe limits prior to 1970s Switched to technology-based control following the 1972 Clean Water Act Back to water quality-based control with field data support since 1980 Modeling to support technology-based and water quality-based control for renewed river BOD/DO problems in the 21st century.

The Day the River Caught Fire: How the Cuyahoga River Exploded and Ignited the Earth Day Movement by Barry Wittenstein

Reviewed by: The Day the River Caught Fire: How the Cuyahoga River Exploded and Ignited the Earth Day Movement by Barry Wittenstein Kate Quealy-Gainer, Editor Wittenstein, Barry The Day the River Caught Fire: How the Cuyahoga River Exploded and Ignited the Earth Day Movement; illus. by Jessie Hartland. Wiseman/Simon, 2023 [48p] Trade ed. ISBN 9781534480834 $18.99 E-book ed. ISBN 9781534480841 $10.99 Reviewed from digital galleys Ad Gr. 2-4 When the Cuyahoga River caught fire in 1969, Cleveland residents were surprisingly unconcerned. “It burned before, people said. It’ll burn again.” The river’s toxic soup of chemicals, oils, and other waste had caught fire thirteen times since 1886, but for Cleveland mayor Carl Stokes, this time was different. In fact, water and air pollution was inspiring environmentalist activism across the country, and Stokes was one of many concerned citizens and experts whose testimony before Congress eventually led to the Clean Air and Water Acts. Earth Day was also born in the aftermath of the fire, in 1970, and eventually became a global movement with people urging corporate and political action to combat pollution and climate change. Centering this exploration of environmentalism on the river provides an accessible entry point to young readers, but that focus never quite allows for the full contextualization of the event within the movement’s arc, nor does it offer one major throughline to connect other events and developments. Mayor Stokes’ contributions, for example, are glossed over soon after he’s introduced, and both Senator Gaylord Nelson and Denis Hayes, considered to be the architects of Earth Day, are relegated to the back matter. Wittenstein does highlight, however, the fact that citizen action did work in this case and that the Cuyahoga River is in much better shape today, with cleaner water and the return of forty different fish species. Illustrations rendered in gouache give depth to river scenes, and palette choice effectively conveys the river’s polluted mess and then its clearer waters. Backmatter includes an author’s note, a timeline, more resources, and a bibliography. Copyright © 2023 The Board of Trustees of the University of Illinois

Mountaintop removal coal mining impacts on structural and functional indicators in Central Appalachian streams.

Mountaintop removal coal mining (MTR) has been a major source of landscape change in the Central Appalachians of the United States (US). Changes in stream hydrology, channel geomorphology and water quality caused by MTR coal mining can lead to severe impairment of stream ecological integrity. The objective of the Clean Water Act (CWA) is to restore and maintain the ecological integrity of the Nation's waters. Sensitive, readily measured indicators of ecosystem structure and function are needed for the assessment of stream ecological integrity. Most CWA assessments rely on structural indicators; inclusion of functional indicators could make these assessments more holistic and effective. The goals of this study were: (1) test the efficacy of selected carbon (C) and nitrogen (N) cycling and microbial structural and functional indicators for assessing MTR coal mining impacts on streams; (2) determine whether indicators respond to impacts in a predictable manner; and (3) determine if functional indicators are less likely to change than are structural indicators in response to stressors associated with MTR coal mining. The structural indicators are water quality and sediment organic matter concentrations, and the functional indicators relate to microbial activity and biofilm production. Seasonal measurements were conducted over the course of a year in streams draining small MTR-impacted and forested watersheds in the Twentymile Creek watershed of West Virginia (WV). Five of the eight structural parameters measured had significant responses, with all means greater in the MTR-impacted streams than in the forested streams. These responses resulted from changes in source or augmentation of the original source of the C and N structural parameters because of MTR coal mining. Nitrate concentration and the stable carbon isotopic ratio of dissolved inorganic carbon were the most effective indicators evaluated in this study. Only three of the fourteen functional indicators measured had significant responses to MTR coal mining, with all means greater in the forested streams than in the MTR-impacted streams. These results suggest that stressors associated with MTR coal mining caused reduction in some aspects of microbial cycling, but resource subsidies may have counterbalanced some of the inhibition leading to no observable change in most of the functional indicators. The detritus base, which is thought to confer functional stability, was likely sustained in the MTR-impacted streams by channel storage and/or leaf litter inputs from their largely intact riparian zones. Overall, our results largely support the hypothesis that certain functional processes are more resistant to stress induced change than structural properties but also suggest the difficulty of identifying suitable functional indicators for ecological integrity assessment.

Hazardous and contaminated sites within salt marsh migration corridors in Rhode Island, USA

As salt marshes attempt to migrate upland due to sea level rise, they will encounter many kinds of land development and infrastructure in highly populated, urbanized coastal communities. Hazardous and contaminated sites (HCSs) -- facilities and infrastructure that store, use, or release harmful substances -- are particularly concerning obstacles to salt marsh migration because of their potential to release contaminants if their structural integrity is compromised. Inventorying HCSs within migration pathways can inform coastal resilience planning. To understand what kinds of HCSs migrating marsh may encounter in Rhode Island, USA, we inventoried sites from federal and state sources, assigned contaminant hazard rankings to most sites, and overlayed them with projected marsh migration corridors. We found that HCSs are extensive across marsh migration corridors in the state, especially in urban areas. Among the most common HCSs in and around Rhode Island salt marshes are stormwater outfalls, underground storage tanks, and facilities registered with EPA's Resource Conservation and Recovery Act (RCRA) or EPA's National Pollutant Discharge Elimination System (NPDES). These sites pose varying hazards to human and aquatic life if breached, with some sites representing little or no threat but most posing some degree of hazard to their surroundings. This coastal HCSs inventory can inform prioritization and management of coastal salt marshes subject to accelerated sea level rise. Management decisions such as allowing marsh migration, implementing adaptation actions to build salt marsh elevation, or erecting physical barriers at marsh sites will influence future salt marsh extent, marshes' ability to provide ecosystem services, and public health exposures to toxic releases. In addition, as Rhode Island and other coastal states work to promote coastal resiliency, this type of inventory can inform decisions about which HCSs to prioritize for remediation and other climate adaptation actions. Marsh migration is just one potential consequence of sea level rise, so many of the considerations outlined here are widely applicable to the broader goal of preparing coastal communities for rising seas.

Conservation of blackwater rivers and streams of the coastal plains of United States: Knowledge and research needs.

Blackwater rivers and streams are a distinct resource type in multiple ecoregions of the United States, including the Coastal Plains. Given the unique nature of blackwaters, they may not be fully protected if using typical water quality standards. Information provided by State agencies was used to identify specific research needs that would directly enhance current assessment approaches. Protection of blackwater rivers and streams would be aided by (1) development of an operational definition; (2) development of a classification framework that distinguishes among blackwater system types; (3) identification of undisturbed or minimally disturbed blackwater systems; (4) identification of stressors that challenge blackwater condition and resilience; and (5) development of criteria that are more suited to the unique conditions of blackwater rivers and streams. Benefits stemming from addressing these research needs may include identification of sites that are unrecognized as impaired and the re-evaluation of sites that may be erroneously listed as impaired when they are not. This would improve reporting by states for Clean Water Act (CWA) Section 305(b) and, for some states, could represent a significant resource savings by reducing the number of sites on CWA Section 303d lists.

Implications of Declining Ground Water and Water Quality in the US Southeastern Coastal Plain Ecoregion and Areawide Environmental Impact Statement Required for Mining in the Greater Okefenokee Swamp Basin—Part 1

Karst aquifers occur worldwide and exhibit groundwater flow responses that differ considerably from aquifers lacking fractures, bedding planes, and other karst conduits where significant and rapid groundwater flow can occur. The regional, karst Floridan aquifer system underlies the United States (US) Southeastern Coastal Plain Physiographic Region and exhibits hydrologic interconnections with overlying surficial aquifers and throughout other zones of the aquifer system, as is characteristic of other karst aquifer systems. Anthropogenic groundwater declines in this regional karst aquifer system have been documented in published literature for decades, but the impacts of those declines in this coastal plain region and the embedded ecosystems that provide essential and critical habitat for native, endemic, and federally endangered and threatened species have not been considered previously. Those anthropogenic groundwater declines reduce surfacewater levels and flows due to the capture of both groundwater and overland flow of surfacewater, resulting in induced recharge through semi-confining zones and interbasin flow through fractures and other karst conduits. This case study identifies examples from the Greater Okefenokee Swamp Basin study area and comparison areas of how those declines result in loss of historic base flow to surface waters and other capture of surface waters, ultimately increasing saltwater intrusion. Those results alter and degrade the physical, chemical, and biological integrity of the nation’s waters, in violation of the US Clean Water Act (CWA) of 1972. Historic groundwater declines from mining and other anthropogenic groundwater withdrawals from this regional karst aquifer system already threaten the survival and recovery of federally endangered and threatened species, as well as existing and proposed critical habitat for those species within this regional extent, in violation of the Endangered Species Act (ESA) of 1973. This case study and its companion publication (Part 2) appear to be the first to provide scientific support for this regional karst aquifer system as the unifying factor in habitat responses to irreversible groundwater impacts on aquatic and marine ecosystems. These adverse impacts strongly suggest that the extent of the regional Floridan aquifer system should be designated as the Southeastern Coastal Plain Ecoregion for the purpose of managing natural resources. Mining activities continue to expand in our study area, which is the Greater Okefenokee Swamp Basin. Despite that fact, no comprehensive Areawide Environmental Impact Statement (AEIS), similar to the AEIS required for phosphate mining within the Central Florida Phosphate District (CFPD) approximately a decade ago has been conducted for any of the numerous mining projects that are occurring and are proposed within the Greater Okefenokee Swamp Basin. This case study also provides examples of why a comprehensive AEIS is essential to consider all of the adverse direct, indirect, and cumulative impacts of those mining activities to the CWA, the ESA, and the irreversible losses to local economies, because federal agencies responsible for considering those adverse impacts rely on public comments to identify those adverse impacts. The mining activities authorized throughout the regional Floridan aquifer system under Category 44 Nationwide Permits (NWP) result in the same type of adverse impacts as the mining activities evaluated under Individual Permits in that region. Therefore, those Category 44 NWP mining activities also should be required to obtain Individual Permits and be evaluated under an AEIS in the Greater Okefenokee Swamp Basin. This case study also describes how Florida’s assumption of the CWA Section 404 regulatory authority in 2020 severs four sub-basins within the Greater Okefenokee Swamp Basin study area at the state line between Florida and Georgia.

Assessment of statistical methods for converting biochemical oxygen demand and carbonaceous biochemical oxygen demand to total organic carbon in wastewater

AbstractThe 5‐day biochemical oxygen demand (BOD5) and carbonaceous BOD5 (CBOD5) tests are widely used parameters for monitoring wastewater. Total organic carbon (TOC) has many advantages over these tests. Wastewater utilities have conducted studies to modify National Pollutant Discharge Elimination System (NPDES) permits to allow TOC analysis; however, statistical methods vary across studies. This study examined parametric and nonparametric correlation and parametric, nonparametric, and nonlinear regression methods for analysing BOD5, CBOD5, and TOC concentrations collected for 1 year from seven wastewater treatment plants from the Metropolitan Water Reclamation District of Greater Chicago. Spearman ρ correlation and Theil–Sen regression on log‐transformed concentrations were the most appropriate methods. Correlation coefficients were 0.83 or greater and regression residuals were as small as or smaller than the other two methods. This study demonstrated that nonparametric methods performed best for analysing non‐normal data in seeking to incorporate TOC analysis into NPDES reporting.

When Chemicals Go to the Dark Side

When Chemicals Go to the Dark Side

Policy action needed to unlock eDNA potential

Policy action needed to unlock <scp>eDNA</scp> potential