Falk M.W.,HDR |
Reardon D.J.,HDR |
Neethling J.B.,HDR |
Clark D.L.,HDR |
Pramanik A.,Water Environment Research Foundation
Water Environment Research | Year: 2013
This Water Environment Research Foundation study considered the relationship between varying nutrient-removal levels at wastewater treatment plants, greenhouse gas emissions, receiving water quality (measured by potential algal production), and costs. The effluent nutrient concentrations required by some U.S. permits are very low, approaching the technology-best-achievable performance. This study evaluated five different treatment levels at a nominal 40 ML/d (10 mgd) flow. Greenhouse gas emissions and costs increase gradually up to the technologies' best-achievable performance, after which they increase exponentially. The gradual increase is attributed to additional biological treatment facilities, increased energy and chemical use, and additional tertiary nitrogen and phosphorus removal processes. Within the limited focus of this study, the evaluation shows that a point of diminishing return is reached as nutrient-removal objectives approach the technology- best-achievable performance, where greenhouse gas emissions and cost of treatment increases rapidly while the potential for algal growth reduce marginally.
McFarland M.J.,Utah State University |
Kumarsamy K.,Utah State University |
Brobst R.B.,U.S. Environmental Protection Agency |
Hais A.,Water Environment Research Foundation
Water Research | Year: 2012
Using the United States (US) Environmental Protection Agency's (EPA) Multimedia, Multi-pathway, Multi-receptor Exposure and Risk Assessment (3MRA) technology, a computer-based biosolids groundwater risk characterization screening tool (RCST) was developed. The RCST, which generates a non-carcinogenic human health risk estimate (i.e., hazard quotient or HQ value), has the ability to conduct screening-level risk-based characterization of potential human risks associated with pollutants released from biosolids land application sites. The HQ is a human health indicator that is equal to the ratio of the pollutant dose (mass of pollutant per unit body weight per time) to the specific pollutant reference dose (Rfd) which, in turn, is a human health benchmark defined by the EPA as a scientific estimate of the daily exposure level. A HQ value equal to or greater than one (1) suggests that the resulting conditions pose an unacceptable risk to human health.The focus of the current study was to evaluate whether the present regulatory limits established for biosolids pollutants (e.g., heavy metals) were sufficiently protective of human health associated with potential groundwater consumption using a new EPA risk assessment tool. Application of the RCST to two biosolids land application sites located near Columbus, Georgia predicted that, when the depth to groundwater was maintained at a distance of at least 2 m, regulated pollutant concentrations as large as ten (10) times the current regulatory limit (i.e., Title 40 of the US Code of Federal Regulations Part 503 - Ceiling Concentration Limit) could be safely land applied at rates as high as ninety (90) Megagrams per hectare (Mg ha-1) with no apparent non-carcinogenic human health effects associated with groundwater consumption. At these pollutant concentrations, the HQ ranged from 1.79 × 10-9 for cadmium to 3.03 × 10-3 for selenium.Only under unrealistically high biosolids application rates were the public health risks associated with groundwater impairment characterized as significant (HQ ≥ 1.0). For example, when the biosolids application rate was increased to 450 Megagrams per hectare (Mg ha-1) and the pollutant concentrations were increased to ten times the 40 CFR Part 503 Ceiling Concentration Limit, a HQ value of 2.23 was estimated (selenium). Similarly, when the biosolids application rate was increased to 900 Mg ha-1 and the pollutant concentrations were increased to ten times the regulatory limit, the HQ ranged varied from 1.4 (for zinc) to 324.0 (for selenium). © 2012 Elsevier Ltd.
Houdeshel C.D.,University of Utah |
Pomeroy C.A.,University of Utah |
Hair L.,U.S. Environmental Protection Agency |
Moeller J.,Water Environment Research Foundation
Journal of Irrigation and Drainage Engineering | Year: 2011
Tools were developed for estimating costs of vegetative roofs, rainwater catchment systems, and bioretention facilities. These tools provide a detailed framework to facilitate cost estimation for capital costs, operation and maintenance costs, and life-cycle net present value. The tools can provide users with planning-level cost estimates and serve as a format for cost-reporting for past, current, and future projects. Very little cost data was available in the public forum, and prolific inconsistencies of supporting details were found in the available cost data. To address this, design assumptions were established for each facility type and professionally prepared cost estimates based on these design assumptions were used. Electives in design, such as plant selection and media depth, also greatly affected costs. To make the user aware of these effects, the model separates each option into line items that can be elected or excluded as appropriate. To facilitate collecting future cost data, best management practice (BMP) designers and builders should use these tools to record actual costs and report them to a clearinghouse such as the BMP Database. © 2011 American Society of Civil Engineers.
Water Environment Research Foundation | Date: 2010-11-09
Downloadable software for analyzing and predicting effective storm water and waste water management; electronic downloadable publications in the nature of scientific reports and research studies in the fields of environmental protection, water quality, waste water and storm water management.
Water Environment Research Foundation | Date: 2010-05-04
Downloadable software for analyzing and predicting effective storm water and waste water management; electronic downloadable publications in the nature of scientific reports and research studies in the fields of environmental protection, water quality, waste water and storm water management. Administering and managing research grants; association services, namely, promoting public awareness in environmental protection, water quality issues and the effective treatment and management of waste water and storm water.