Effects Of Combined Sewer Overflows Research Articles

Othermothering in Detroit, MI: understanding race and gender inequalities in green stormwater infrastructure labor

ABSTRACT As cities increasingly look towards the promotion of green stormwater infrastructure (GSI) in order to mitigate the effects of combined sewer overflows and stormwater pollution, the role of citizen labor is often expected and required for the success of these projects. Cities in the United States have come to rely upon such contributions from residents, however, very rarely do policies consider the impact of this request of labor. This paper aims to address this gap by employing Patricia Hill Collins’ theoretical framework of Othermothering in order to analyze qualitative data collected in 2017 with a Detroit city sponsored GSI educational program. Combined with ethnographic storytelling, I highlight the work Black Detroit women are putting into improving their city and argue for the application of a Black feminist social reproduction lens in understanding current race and gender divides in volunteer labor within GSI Initiatives. Together, analysis reveals how the labor contributed by Black women continues to be unfairly requested, unpaid, and essential to the success of GSI projects, while also becoming a site of resistance for larger structural inequalities in the surrounding urban landscape.

Temporal and spatial variations of water quality in the Newark Bay Estuary

Long-term (summer 2015–2018 and short-term (summer 2018) water quality monitoring was performed to understand spatial and temporal variations of surface water quality in the Newark Bay Estuary, as well as the Upper New York Bay, parts of the Hudson-Raritan Estuary in the New York–New Jersey metropolitan area. Electrical conductivity (EC), pH, temperature, and dissolved oxygen (DO) were measured in the field, while dissolved nitrate, phosphate, and ammonia concentrations were determined in the laboratory. Long-term and short-term water quality monitoring data consistently indicated that nutrients are significantly elevated in the Hackensack River most likely due to sewage effluent from a major sewage treatment plant. Dissolved oxygen levels were sufficiently high in most parts of the estuaries, whereas the Hackensack River showed a sign of hypoxia. Nutrients in the estuaries showed significant temporal variations typically by 2 to 3-fold during the 1-month short-term monitoring period, and were correlated with EC, DO or pH. The effects of combined sewer overflows (CSOs) during wet weather on the water quality of Newark Bay appeared uncertain except for ammonia, but long-term effects of CSOs need to be further investigated because nutrients from CSOs can accumulate in bottom sediments and be remobilized. Frequent water quality monitoring is necessary to better understand the impact of human activities on temporal variations of nutrients in urban estuaries and to efficiently protect coastal ecosystems.

Long-term and comparative impacts of combined sewers and municipal effluents to freshwater mussels

Excess rainfall events could lead to overflows and combined sewer overflows, which could threaten local mussel populations. This study sought to compare the long- term effects of combined sewer overflows and treated municipal effluents in caged Elliptio complanata mussels. Mussels were caged at 2 overflow sites, one downstream site of a major municipal effluent dispersion plume and a reference upstream site for 3 months during the summer. At the end of the exposure period, mussels were collected, analyzed for municipal contaminants (including pharmaceuticals), and effects biomarkers based on endocrine disruption (vitellogenin expression), xenobiotic detoxification (glutathione S-transferase and metallothioneins), oxidative stress/inflammation (cyclooxygenase and lipid peroxidation) and DNA damage. The data revealed that surface waters contained less pharmaceutical products than the downstream site but atrazine and its metabolite were at higher levels in overflow sites. Mussels contained elevated amounts of total heterotrophic bacteria, caffeine, acebutolol and venlafaxine at the downstream site relative to the upstream site where caffeine was higher at one of the overflow site. The levels of vitellogenin gene expression were significantly increased in both sexes of mussels caged at the downstream site only. Multivariate analysis revealed that the biomarker responses were completely separated between upstream, overflow and downstream sites. The site discrimination was based on vitellogenin, metallothioneins, DNA damage in gonad and digestive gland, gonad lipids/proteins reserves, lipid peroxidation, gonado-somatic index and condition factor. Adverse outcome pathways analysis using the power law approach revealed that most changes in the biomarkers identified by discriminant function analysis were significantly scaled to gonad energy reserves, tissue/ mussel size and loss of weight following air emersion stress. In conclusion, the toxic effects of mussels caged at overflow sites generally displayed lower responses than mussels caged downstream a treated municipal effluent suggesting that these overflows pose a lower risk than the continuous exposure to treated municipal effluent.

Effects of combined sewer overflows and storm water drains on metal bioavailability in small urban streams (Prague metropolitan area, Czech Republic)

The aims of the study were to evaluate the effect of combined sewer overflows (CSO) and storm water drains (SWD) on metal bioavailability in small urban streams in Prague and to evaluate levels of metals in water, sediment, and macroinvertebrates. The following working hypotheses were adopted: (a) sites dominantly affected by SWD are less polluted by metals, and (b) sites dominantly affected by SWD have higher bioavailability of metals. Physical and chemical parameters (pH, conductivity, NO3-N, NH4-N, COD, alkalinity, and water hardness) and concentrations of the metals Cu, Zn, Pb, Ni, and Cr were determined in samples of water and sediment at five to six sites on four target streams—Zatisský Creek, Kosikovský Creek, Botic Creek, and Rokytka Creek—three to five times per year during the period 2002–2004. The sites from all studied creeks were categorized into five groups according to the prevailing type of urban drainage impact. Macroinvertebrates were sampled and analyzed for metals at each site for a period of 1 month. The concentration patterns of metals were interpreted by partition coefficient (Kd), hazard quotient (HQ), cumulative criterion unit (CCU), and biota sediment accumulation factor (BSAF). Concentrations of metals in water as well as in sediment at sites receiving water from SWD were lower than at sites where creeks receive water from CSO, except for Pb. Concentrations of Cu, Zn, and Pb in sediment were higher at sites affected by CSO. Concentrations of metals in aquatic macroinvertebrates, expressed as BSAF, indicated higher values at sites affected by SWD. Frequencies of high BSAF (>1) were lower in CSO compared to SWD. This finding was explained by (a) a decrease of pH on SWD sites compared to the increase of pH on CSO sites during rain events, (b) a greater resuspension of sediment at SWD sites during rain events, and (c) an abundance of organic matter in CSO available for sorption of metals and a corresponding reduction of their bioavailability. In the study area, the type of urban drainage affects the bioavailability of metals—while SWD increase metal bioavailability, CSO cause its decrease. The sediments in SWD sites do not indicate risk to the benthic community according to the applied environmental quality standards. Water and sediment in creeks affected by SWD are less polluted by metals. Both working hypotheses were therefore supported.

Nitrogen patterns in subsurface waters of the Yzeron stream: effect of combined sewer overflows and subsurface–surface water mixing

Urbanization subjects streams to increased nitrogen loads. Therefore studying nitrogen forms at the interface between urban stream and groundwater is important for water resource management. In this study we report results on water δ(18)O and nitrogen forms in subsurface waters of a stream (Yzeron, France). The sites studied were located upstream and downstream of combined sewer overflows (CSO) in a rural area and a periurban area, respectively. Water δ(18)O allowed us to follow the mixing of subsurface water with surface water. Dissolved organic nitrogen and organic carbon of fine sediment increased by 20-30% between rural and periurban subsurface waters in the cold season, under high flow. The highest nitrate levels were observed in rural subsurface waters in the cold season. The lowest nitrate levels were found in periurban subsurface waters in the warm season, under low flow. They corresponded to slow exchange of subsurface waters with channel water. Thus reduced exchange between surface and subsurface waters and organic-matter-rich input seemed to favor nitrate reduction in the downstream, periurban, subsurface waters impacted by CSO.

Model based hydropower gate operation for mitigation of CSO impacts by means of river base flow increase

In river stretches being subjected to flow regulation, usually for the purpose of energy production (e.g. Hydropower) or flood protection (river barrage), a special measure can be taken against the effect of combined sewer overflows (CSOs). The basic idea is the temporal increase of the river base flow (during storm weather) as an in-stream measure for mitigation of CSO spilling. The focus is the mitigation of the negative effect of acute pollution of substances. The measure developed can be seen as an application of the classic real time control (RTC) concept onto the river system. Upstream gate operation is to be based on real time monitoring and forecasting of precipitation. The main objective is the development of a model based predictive control system for the gate operation, by modelling of the overall wastewater system (incl. the receiving water). The main emphasis is put on the operational strategy and the appropriate short-term forecast of spilling events. The potential of the measure is tested for the application of the operational strategy and its ecological and economic feasibility. The implementation of such an in-stream measure into the hydropower's operational scheme is unique. Advantages are (a) the additional in-stream dilution of acute pollutants entering the receiving water and (b) the resulting minimization of the required CSO storage volume.

Storing Overflows Underground

To reduce the volume and effect of combined sewer overflows entering local waterways, a series of new pipelines and a facility for treating overflows were installed in Seattle.

Evaluation of the Water Quality Effects of Combined Sewer Overflow (CSO) Control Measures

At present, design guidelines for combined sewer systems ere being formulated by the water pollution control authorities in the Netherlands. These guidelines are aimed at the reduction of pollutant loads by means of stormwater sedimentation tanks and the increase of storage capacity. To obtain better knowledge of the water quality aspects of the guidelines, the effects of combined sewer overflows from systems with stormwater sedimentation tanks of varying storage capacity were studied. Three receiving water bodies, with different dimensions and base flow, were reviewed. For the evaluation of effects on the oxygen balance a combined simulation model was used to predict the pollutant load and the dissolved oxygen response of individual overflow events. Eutrophication effects and accumulation of micropollutants were judged from the annual discharge data. It appeared that in small, stagnant ditches, the guidelines will induce a sharp reduction of the number of violations of the dissolved oxygen standard. In larger, flowing waters, the guidelines may adequately protect the water against violation of these standards. The discharge of total phosphorus and micropollutants is largely reduced by the prescribed measures. However, other sources of phosphorus must be eliminated as well to combat eutrophication effectively.

Health effects associated with waste treatment, disposal, and reuse

and transfer of fecal indicator organisms (coliforms, enterococci, sulphite-reducing clostridia, and coliphages) downstream of a wastewater treatment plant were investigated at Lake Kallavesi, Finland (R?jala and Heinonen-Tanski, 1998). The observation of indicator organisms up to 18 km from the discharge point and good survival in the summer suggested that direct use of lake water could constitute a health risk. The effect of combined sewer overflows (CSOs) on the occur rence of Giardia and Cryptosporidium was investigated (Gibson et al., 1998). The results suggested that CSOs significantly contribute to the load of Giardia and Cryptosporidium in ambient waters and source waters for drinking and recreational uses. An outbreak of waterborne giardiasis in Temagami, Ontario, in 1994 was assessed (Wallis et al., 1998). The outbreak was traced to leakage from the municipal wastewater system into the lake and exacerbated by spring snow-melt runoff. The influence of rainwater on the con centration of helminth eggs in wastewater was investigated (Capizzi and Schwartzbrod, 1998). Concentrations of parasite eggs vary according to water flow rates and sedimentation; heavy rain following rainless days yielded higher concentrations in raw wastewater at the treatment plant, whereas continuous moderate rain resulted in low variation of parasite eggs. The prevalence of respiratory symptoms, skin disorders, status of spirometric lung functions, and amino acid profiles among wastewater workers were reported (Bener et al., 1998). Wastewa ter workers had a higher prevalence of respiratory symptoms than controls, significant for chronic cough (p < 0.02), chronic phlegm (p < 0.03), chronic bronchitis (p < 0.02), asthma (p < 0.02), dyspneoa (p < 0.001), and nasal catarrh (p < 0.001) and acute symptoms of pruritus (p < 0.003), tinea (p < 0.004), dermatitis (p < 0.001), and nose irritation (p < 0.005). Spirometry tests scored lower in wastewater workers, and most of the plasma amino acids concentrations were elevated among wastewater workers. An investigation examining whether inadequate septic system construction may cause contamination of wells with coliform bacteria or nitrates was reported (Tuthill et al., 1998). The authors found that coliform bacteria and nitrate contamination were neg atively correlated with lot size, and coliform bacteria levels were negatively correlated with casing length, which suggested that septic systems may be a source of coliform bacteria and nitrate contamination in wells. CONTAMINATION OF WATER SUPPLIES

Urban Storm Water Discharges: Effects upon Communities of Sessile Diatoms and Macro-Invertebrates

From 1985 to 1987, long-term and more or less permanent effects of discharges from combined or separate sewer systems on communities of sessile diatoms and macro-invertebrates in receiving waters have been studied. Sessile diatoms and/or macro-invertebrates have been investigated on 46 locations, spread all over The Netherlands. The results were related to the type of sewer system, the discharges, and the characteristics of the receiving water, and compared with results from sample(s) taken from a corresponding water not influenced by sewer overflows, the reference water. In general, communities of sessile diatoms and macro-invertebrates indicate a more severe organic pollution and disturbance of receiving waters compared with reference waters. In the immediate vicinity of the overflows these communities were more disturbed than at some distance. In small ditches, effects were more pronounced compared with large waterbodies and waters with a constant flow regime. Finally, effects of combined sewer overflows were more pronounced than effects of discharges from separate sewer systems, except for locations in industrial areas.