Search

Studies have shown that fecal contamination can be determined by conducting multiple antibiotic resistance (MAR) analyses. The hypothesis is if bacteria exhibit resistance, they are likely to be derived from organisms exposed to antimicrobial agents. Therefore, this project seeks to apply MAR analysis to nonpoint source (NPS) and combined sewer overflow (CSO) areas along the Anacostia River in Washington, DC. Presumptive E. coli was isolated from NPS and CSO samples and tested with eight different antimicrobial agents to assess MAR indices. Isolates from CSO sources showed significantly greater resistance (p < .05) and higher MAR indices, with an average MAR index of 0.36 for CSO samples and 0.07 for NPS samples. It was also revealed that 96.9% of CSO isolates exhibited resistance, versus only 43.8% of NPS isolates. Our study on the Anacostia River using this approach clearly shows fecal coliforms are associated with CSO overflows, indicating that pollution-derived coliform levels are strongly linked to antimicrobial resistance. The implementation of this method as an index for water quality in the remediation of the Anacostia River has the ability to serve as a model and monitoring tool for the rehabilitation of urban watersheds. [ABSTRACT FROM AUTHOR]

Onsite wastewater treatment systems (OWTS) are commonly used in coastal areas to treat household wastewater. These systems represent potential sources of fecal pollution of groundwater and nearby surface water. OWTS are expected to reduce microbial concentrations in wastewater; however, system and environmental factors can affect treatment efficiency and impacts on ground and surface water. In the study of OWTS described in this article, the authors sampled septic tanks and groundwater at two households in coastal North Carolina between October 2009 and October 2011. Samples were tested for the fecal indicator microbes E. coli, enterococci, and Clostridium perfringens. Microbial source tracking was also performed in year two. Results showed that enteric microbe concentrations in groundwater significantly decreased with distance from the OWTS. Human markers of fecal contamination were also detected in the OWTS and downgradient groundwater, indicating that OWTS can impact the microbial quality of shallow groundwater. [ABSTRACT FROM AUTHOR]

After years of irrigating farmland with wastewater, concern is increasing about health risks from heavy metals contaminating wheat grown in sewage-irrigated soils in suburban areas of Beijing, China. The study discussed in this article aimed to compare the characteristics of heavy metal distribution in a sewage-irrigated “soil-wheat” system with those from a clean-water-irrigated area by collecting and analyzing samples from both areas. The results indicated that the average concentrations of copper, chromium, lead, and zinc in sewage-irrigated soil were higher than the values in the clean-water-irrigated region. Irrigation with wastewater could lead to increased bioconcentration factors. Therefore, issues of food contamination caused by sewage irrigation deserve more attention. [ABSTRACT FROM AUTHOR]

The objective of the study described in this article was to evaluate the nitrogen contributions from two onsite wastewater systems (sites 1 and 2) to groundwater and adjacent surface waters in coastal Beaufort County, North Carolina. Groundwater levels and water quality parameters including total nitrogen, nitrogen species, temperature, and pH were monitored from October 2009 to May 2010. Nitrogen was also tested in groundwater from deeper irrigation or drinking water wells from the two sites and six additional neighboring residences. Mean total nitrogen concentrations in groundwater beneath onsite wastewater systems 1 and 2 were 34.3 ± 16.7 mg/L and 12.2 ± 2.9 mg/L, respectively, and significantly higher than background groundwater concentrations (<1 mg/L). Groundwater in the deeper wells appeared not to be influenced by the onsite systems. Groundwater nitrogen concentrations typically decreased with distance down-gradient from the systems, but were still elevated relative to background conditions more than 15 m from the systems and near the estuary. This was a pioneering effort to better understand the link of onsite systems, the fate of nitrogen in the environment, and public health. [ABSTRACT FROM AUTHOR]

The efficacy of three septic tank additives and a control was assessed using a randomized complete-block design in a double-blind study described in this article. Sludge depth, scum thickness, and total solids were measured within 48 full-scale, functioning septic tanks. These tanks were distributed across three sites with low, intermediate, and high prior-maintenance levels. No significant, positive long-term additive treatment effects occurred across all maintenance levels at the α = .05 level. Separate analyses of variance, however, indicated that at the high prior-maintenance site, significant treatment effects occurred on sludge depth, scum thickness, and total solids. Sludge depths for the Liquid-Plumr and Rid-X additives were significantly reduced compared to the control at the high-maintenance site, but not at the low-maintenance site. Liquid-Plumr septic tank additive had significantly greater sludge depth at the intermediate-maintenance site, which is a negative impact. Sludge accumulation rates averaged 6.9 cm/yr. for 3,780-L (1,000 gallons) septic tanks. [ABSTRACT FROM AUTHOR]

The efficacy of 1,200+ septic tank additives on the market has always been a concern due to the previous lack of independent, replicated, third-party, field-scale research studies. Twenty experimental units (well-maintained, full-size, functioning septic tanks) were pumped out 2-3 years before being assessed in the study presented here. These units were treated with one of three biological additives or a control in a double-blind study. Effluent data analyzed using a mixed linear model showed that the overall treatment effect was significant for effluent five-day biochemical oxygen demand (BOD5) concentrations. One additive had significantly lower effluent BOD5 concentrations in septic tank effluent than the control and the other two additives had the same BOD5 as the control. No statistically significant effluent total suspended solids concentration effect occurred for any additive. These results were also considered in concert with two prior related studies regarding microbiological contents as well as sludge and scum accumulation rates across three prior-maintenance levels in 48 septic tanks. [ABSTRACT FROM AUTHOR]

Reports on Control Instruments Corp.'s Model FAA Gas Detection Sensor for continuous solvent vapor monitoring in wastewater applications. Capabilities; Specifications.

Features WTW Measurement Systems Multi 197i meter that offers multi-parameter field testing of waste water. Characteristics of waste water that can be measured using the meter; Depth range within which the measurements can be made; Other features of the meter.

This article reports on failure rates in onsite sewage treatment systems (STS) that were found as part of a comprehensive seven-county survey that was performed under the auspices of the Northeast Ohio Areawide Coordinating Agency (NOACA) during the summer of 2000. The goal was to determine the percentage of onsite, individual home wastewater systems that were "failing." A system was identified as "failing" if, upon inspection, it had observable surfacing of effluent from the treatment system. A certified soil scientist conducted each on-site investigation to ensure consistency in methodology and to provide verification of soil types for each installation. The survey revealed that between 12.7% and 19.7% of the onsite wastewater treatment systems are allowing wastewater to surface as opposed to infiltrate (at the 95% confidence interval). The rate of failure does not vary significantly between aerobic and septic systems or between systems with or without filters.

Aerobic treatment units (ATUs) are used to enhance or replace traditional septic-tank/drainfield onsite sewage treatment and disposal systems (OSTDS). The objective of the study reported here was to assess the performance of ATUs under real-life conditions. Monroe County Health Department personnel in the Florida Keys sampled two-thirds of approximately 1,200 ATU systems on record during 2000 and 2001. Grab samples were analyzed for five-day carbonaceous biochemical oxygen demand (CBOD5), total suspended solids (TSS), total nitrogen (TN), and total phosphorus (TP). Results showed a non-normally distributed wide range of concentrations from less than 1 to thousands of milligrams per liter. In about half of the grab samples, TSS exceeded 30 mg/L, and in a quarter, CBOD5 exceeded 25 mg/L. Concentrations differed significantly (p < .05) by sampling point location, with CBOD5 and TSS more affected than TN and TP These results reflected significantly higher concentrations at sampling ports and additional treatment occurring in system components after treatment by the ATU. Differences by day of week and by month were also significant (p < .05), but time of day was not associated with significant differences. No significant improvement was found with newer ATUs over older ones. The high variability of ATUs and the low frequency of sampling pose a challenge to monitoring and enforcement programs.

This retrospective cohort study used existing data to evaluate the quality of effluent from three of the most common types of onsite residential aerobic treatment sewage systems (Multi-Flo, Norweco, and Whitewater) installed in Kitsap County, Washington. Five-day biochemical oxygen demand (BOD5), total suspended solids (TSS), and fecal-coliform-bacteria parameters were used to determine performance. Although most (77 percent) of the systems were less than one year old at the time of sampling, over a third failed to meet NSF certification standards for BOD5 and TSS in effluent (< 30 milligrams per liter [mg/L]). Over two-thirds of systems failed to meet Washington State Board of Health Treatment Standard 2 criteria for BOD5 and TSS (< 10 mg/L). Furthermore, an average of 59 percent of the systems failed to meet state standards for fecal coliform (< 800 fecal coliform bacteria per 100 milliliters).