Role of a Comprehensive Toxicity Assessment and Monitoring Program in the Management and Ecological Recovery of a Wastewater Receiving Stream

Abstract

National Pollution Discharge Elimination Permit (NPDES)-driven effluent toxicity tests using Ceriodaphnia dubia and fathead minnows were conducted for more than 20 years to assess and monitor the effects of wastewaters at the United States (U.S.) Department of Energy Y-12 National Security Complex (Y-12 Complex) in Oak Ridge, Tennessee. Toxicity testing was also conducted on water samples from East Fork Poplar Creek (EFPC), the wastewater receiving stream, as part of a comprehensive biological monitoring and assessment program. In this paper, we evaluate the roles of this long-term toxicity assessment and monitoring program in the management and ecological recovery of EFPC. Effluent toxicity testing, associated toxicant evaluation studies, and ambient toxicity monitoring were instrumental in identifying toxicant sources at the Y-12 Complex, guiding modifications to wastewater treatment procedures, and assessing the success of various pollution-abatement actions. The elimination of untreated wastewater discharges, the dechlorination of remaining wastewater streams, and the implementation of flow management at the stream headwaters were the primary actions associated with significant reductions in the toxicity of stream water in the upper reaches of EFPC from the late 1980s through mid 1990s. Through time, as regulatory requirements changed and water quality improved, emphasis shifted from comprehensive toxicity assessments to more focused toxicity monitoring efforts. Ambient toxicity testing with C. dubia and fathead minnows was supplemented with less-standardized but more sensitive alternative laboratory toxicity tests and in situ bioassays. The Y-12 Complex biological monitoring experience demonstrates the value of toxicity studies to the management of a wastewater receiving stream.

Wastewater and Landfill Leachate Testing: Acute Toxicity Biotest Results Evaluation

“…More recently, there appeared another important feature of aquatic toxicity data scoring systems -their universality. The same values based scoring systems are used for different origin aquatic samples: 1) pT-values based classification, applied for WWs (Krebs 2005), was used also for sediment materials (porewater, elutriates, extracts, and solid phases); 2) TU based acute toxicity classes initially were proposed for waste dumps and WW; later these were used for aquatic toxicity evaluation (Sauco et al 2013), with microbiotests in many countries for different environmental samples: natural waters (Greeley et al 2011), WWs (Kontana et al 2008;Carbonell et al 2010); soils, sediments, wastes, biotoxins, etc. Alternatively, TU based classes were used in municipal solid waste (MSW) incineration bottom ash toxicity evaluation (Lapa et al 2006;Tsiridis et al 2012); 3) Potential Ecotoxic Effect Probe, PEEP index was used for WET, integrating TB data (TU form), persistence and WW flow rate (Q), was later modified (without Q, etc.)…”

Multidecadal biological monitoring and abatement program\ assessing human impacts on aquatic ecosystems within the Oak Ridge Reservation in eastern Tennessee, USA

“…While not necessarily pristine, the reference sites share similar geological characteristics and do not have high levels of effluent discharge and/or human influence (McManamay et al, 2018). The BMAP data record shows decreasing toxicity of receiving waters (Greeley et al, 2011) and the recovery of fish and macroinvertebrate communities (Adams et al, 2005; Ryon, 2011; Smith, 2003; Smith et al, 2011) resulting from abatement efforts. Further, bioaccumulation data from BMAP has demonstrated the complex biodynamics of mercury and methylmercury within stream ecosystems, particularly regarding relationships between aqueous and tissue‐bound Hg in fish and consumer‐driven contaminant cycling (Adams et al, 2002; Mathews et al, 2013; McManamay et al, 2019; Southworth et al, 2011).…”

“…Toxicity tests are regularly conducted using standard aquatic test organisms, specifically the water flea, Ceriodaphnia dubia , and the fathead minnow, Pimephales promelas , at least annually and more frequently in some locations following the rigorous methods outlined by the EPA (EPA‐821‐R‐02‐012 and EPA‐821‐R‐02‐013 for acute and chronic testing, respectively; USEPA, 2002a and 2002b). Toxicity testing has been conducted regularly in some BMAP sites since at least 1986 (Greeley et al, 2011). This testing is frequently supplemented by in‐situ bioassays, such as the placement of caged clams in natural waterways to measure impacts on survival and contaminant bioaccumulation.…”