Concerns about water quality degradation resulting from land appliation of manures and biosolids have elicited a wide array of national and state regulations. The regulations focus on P as the limiting nutrient to eutrophication of most freshwater supplies and threaten to severly impact biosolids recycling. Critical data about biosolids-P phytoavailability and run-off potential, especially field data, needed to validate the regulations are scarce. The goal of this reseach was to supply such data. Conventionally treated biosolids exhibit both less agronomic and environmental impact, such as...

A laboratory study was conducted to elucidate the source-effect relationships for seven chemicals (sources) that can cause activated sludge process upset (effect). These chemicals were studied over a range of concentrations using both nitrifying and non-nitrifying laboratory-scale activated sludge sequencing batch reactors. Effects were characterized according to traditional methods of evaluating process effluent and mixed liquor quality. A range of process effects were observed for both biomass sources. Overall impact was assessed and the degree to which a chemical caused an impact on...

Microbial risk assessment is a structured approach to estimating risks associated with environmental exposure to pathogens by using available environmental data. In this report the researchers took advantage of pathogen monitoring of raw sludge efficacy of treatment processes, and pathogen monitoring of post-treatment biosolids. This risk assessment approach is able to estimate risks even for Class A biosolids where post-treatment monitoring data are all below the detectable level. Using this approach this report provides risk estimates for a number of different models to gain insight into...

The researchers have developed a methodological framework that aims to provide a predictive approach to water quality criteria selection. The basic constituents of the proposed methodology are expert elicitation and structural equation modeling. Expert elicitation was used to quantify the narrative designated use, identify the conditions for use attainment, and was further invigorated by engaging multiple experts and formalizing the elicitation protocol. Structural equation modeling provided a complementary tool that enabled the linkage of realistic ecological structures -founded on routinely...

The USEPA's ambient water quality criteria (AWQC) for cyanide were developed in 1984. Recently, however, concerns have arisen that the AWQC for cyanide have been problematic to implement and may not accurately reflect either the toxic forms or bioavailable concentrations of cyanide in water, sediments, and tissues of aquatic organisms. Also, the cyanide criteria typically have been implemented based on total cyanide concentrations rather than the free cyanide concentrations that formed the basis of the criteria calculations. New knowledge on cyanide toxicity, cyanide speciation and its...

A large portion of impaired waterways are located in or near urban areas and are adversely influenced by stormwater-borne solids. The solids have negative impacts on receiving water systems including loss of aquatic habitat, channel instability, and the transport of harmful pollutants potentially hazardous to human and ecosystem health. The current methods for sampling, handling, and analyzing stormwater solids don't lead to a good understanding of these effects on receiving waters.
The purpose of the study is to develop a draft protocol addressing sampling, analysis, and reporting...

In order to facilitate more effective integration of monitoring data and technically sound assessment methodologies into the waterbody assessment and listing process, a critical evaluation of the current methodologies employed by the states was recognized by WERF. Funding was provided to document and evaluate current assessment and listing methodologies employed by the states during the development of their Integrated Reports. The findings from the review of current waterbody assessment methodologies presented herein provides a comprehensive overview of the current state of the science for...

This report is the summary of a portion of a larger-scale project titled Salt Creek Water Quality Studies (SCWQS) performed by the City of Lincoln, Nebraska, for an approximate seven year period from 1994 through 2000, to address proposed ammonia effluent limits for the City's two wastewater treatment plants (WWTPs).
The project focused on characterizing Salt Creek by quantifying the existing biological community, evaluating existing water quality, physical and hydrologic conditions, and evaluating the impact of ammonia discharges from the WWTPs to the biological community compared to...

There is a tremendous amount of literature on and experience with wastewater disinfection alternative. However, it is difficult for wastewater professionals to sift through all of the available information, especially for relatively newer technologies. In addition, there are many factors, some of them site-specific, that influence whether a facility changes disinfection practice, and which alternative it chooses. There are few resources that provide a comprehensive discussion of decision factors with a direct comparison of the disinfection alternatives.
This project developed a singular...

Phase 3 of the overall WERF project was developed to study eight Phase 2 hypotheses in more depth, beginning in the laboratory (bench-scale) studies and continuing on to targeted investigations where the WERF team manipulated plant parameters at full scale to identify the best means of reducing biosolids cake odors. The Phase 3 research specifically sought ways to enhance anaerobicly digested and dewatered biosolids to reduce the odor levels in the biosolids end product, thereby reducing negatively perceived impacts on the environment or to the public when beneficially used on land.
The...