Wastewater Outfall Research Articles

Increased diversity of macroinvertebrates, but not fish, near wastewater outfalls in the Red River Basin, Oklahoma

The reuse of wastewater for beneficial purposes (e.g. irrigation) can boost water sustainability, but may have positive or negative impacts on the environment. In some drought-prone or over-allocated river basins, wastewater is an important component of stream flows and may buffer river ecosystems from drought. In these locations, wastewater may have a net positive impact on river ecosystems and its capture and reuse would be harmful to these ecosystems. In other locations, wastewater may have a net negative impact if the quality of the wastewater (i.e. concentrations of contaminants and nutrients) is lower than that of the receiving water body. In this study, we quantified the effects of wastewater on fish and macroinvertebrate communities in the Red River, Oklahoma. We investigated two competing hypotheses. First, we hypothesized that if wastewater flows buffer aquatic communities from drought, then measures of biodiversity should be higher at sampling sites near wastewater outfalls than at sites not near wastewater outfalls. Second, we hypothesized that if wastewater outfalls negatively impact water quality or homogenize the flow regime, then measures of biodiversity should be lower at sites near wastewater outfalls. To test these competing hypotheses, we calculated a suite of biodiversity indices at 320 biological sampling sites in the Red River Basin and analyzed for significant differences in communities based on proximity to wastewater outfalls. We found that proximity to upstream wastewater outfalls had significant positive impacts on macroinvertebrate community biodiversity, but we did not find any significant relationships with fish community diversity. Findings from this study provide insight to management decisions on wastewater reuse initiatives in beneficial subbasins while minimizing harmful ecological impacts.

Natural vs. anthropogenic sources of N-Nitrosodimethylamine precursors in surface water

N-nitrosodimethylamine (NDMA) is a carcinogenic disinfection byproduct formed from reactions between dichloramine and organic nitrogen-containing precursors. It is unclear if NDMA precursors in surface water intakes originate in anthropogenic (i.e., wastewater) or natural sources. The Truckee River has a single point source release of treated wastewater effluent, making it an ideal system to study the relative importance of precursor sources. Three Lagrangian sampling events were conducted. NDMA formation potential (FP, a measurement of precursors) above the wastewater outfall indicated that the natural background of NDMA precursors was 2-28 ng/L. NDMA FP increased to 18-31 ng/L immediately downstream of the wastewater outfall, but decreased rapidly in a first order manner, and were not statistically different from the upstream samples in only ∼6 km. This suggests that the dominant source of NDMA precursors may be wastewater derived only near wastewater outfalls and deviates from the previous belief that wastewater-derived precursors are responsible for NDMA formation in drinking water sources located further downstream. Additionally, given the rapid loss of the wastewater precursors in this study, precursors which are slow to biodegrade/photolyze/adsorb to sediment are likely to be poor surrogates for the overall wastewater NDMA precursor pool. To understand temporal changes in the wastewater impact on environmental NDMA precursor loading, two 24-hour sampling events were conducted near (<3 km) the wastewater outfall and demonstrated that temporal changes in the NDMA precursors directly downstream of the wastewater outfall are directly linked to the wastewater flow contribution.

Application Of Remote Sensing Technologies On Industrial Outfalls

Industrial effluents are a byproduct of various industries. They may contain harmful and toxic substances of organic or inorganic origin, such as pesticides, pharmaceuticals, hydrocarbons, detergents, and oils. In addition, industrial effluent can also come from thermal power plants in the coastal area, which use seawater for cooling, which they return to the environment after the process. Hence, the zone near the outlet has increased temperature, affecting the mortality and reduction of certain types of fish and algae, variations in the number of phytoplankton, and other ecological problems (Zhao et al., 2015). Nowadays, an increasing amount of industrial wastewater from desalination processes is brine, which is considered a minor risk to public health but has a more significant impact on the environment (Lattemann and Amy, 2013). Due to the increase in population, the demand for drinking water has increased, especially on the islands and coastal areas. With the desalination process, drinking water is produced from sea or brackish water by removing suspended matter and dissolved minerals, mainly salt, and the effluent, i.e., brine, is discharged back into the coastal area. An increased amount of salt can potentially negatively affect the marine ecosystem, leading to the dehydration of cells and possible death of organisms (Missimer and Maliva, 2018). In addition, the brine may have a higher temperature than the environment and contain heavy metals and residues of hazardous chemicals applied in the process, such as anti-scale agents, flocculation agents, and coagulants (Panagopoulos and Haralambous, 2020.). The increasing hydrogen generation from renewable sources requires more freshwater. Consequently, a significant increase in this type of effluent is expected in the future. Therefore, analysis and monitoring of the operation of industrial outfalls is essential to preserve the marine environment and public health. Previous research (Law and Tang 2016) proposes long-term monitoring after the outfall has been commissioned to study environmental effects. Historically, monitoring of wastewater outfalls was mainly obtained by in situ sampling methods to ensure water quality in coastal areas (Gierach et al., 2017). Such practices have temporal and spatial limitations with high costs; hence, they are impractical for analyzing a larger coastal area. Therefore, in this research, we propose using remote sensing technologies for monitoring industrial outfalls.

Wastewater Effluent from Outfalls in Kuwait Bay: A Threat to Recreational Water Quality

The implications of wastewater discharge into marine ecosystems are gravely concerning due to their ability to trigger a chain reaction of contaminants that pose severe risks to both humans and aquatic life. Kuwait Bay is no exception, with numerous wastewater outfalls posing a threat to the marine environment on its southern coasts. This study sought to extensively evaluate the recreational water quality adjacent to wastewater outfalls at five specified sites and compare the results according to the KEPA's (Kuwait's Environmental Public Authority) guidelines. Field measurements and laboratory analyses were conducted to gauge various parameters associated with water quality, such as nutrients, heavy metals, fecal bacterial indicators (FBI), and pharmaceutical compounds. The results of field measurements indicated that two locations had insufficient DO levels with values &lt; 4 mg/l below KEPA standards and brackish to saline water concerning Electrical conductivity (EC) measurements. However, the heavy metal results demonstrated mercury (Hg) pollution at all locations, whereas the nutrient data revealed significant PO4-P concentrations. Furthermore, EPA requirements were considerably exceeded for bacterial indicator counts (fecal coliforms, E. coli, and fecal streptococci), suggesting serious biological pollution at these locations and elevated concentrations of paracetamol and ranitidine have been detected in pharmaceutical compound analysis, particularly in location OC5. The study's findings emphasized the significance of periodic surveillance to ensure the ongoing improvement of water quality and public health in Kuwait's coastal zones and highlighted the dire need to address the extensive contamination by implementing measures to mitigate the dump of unprocessed wastewater into the sea.

LIBS sensing for in-situ iron detection and quantification in wastewater outfall

LIBS sensing for in-situ iron detection and quantification in wastewater outfall

Spatial distribution of microplastics in a coastal upwelling region: Offshore dispersal from urban sources in the Humboldt Current System

In coastal waters, higher concentrations of microplastics (MPs) are generally related to densely populated and industrialized areas, but intense upwelling and offshore transport in the Eastern Boundary Upwelling Systems (EBUS) may influence this pattern. The Humboldt Current System (HCS) along the coast of northern-central Chile represents a perfect model to test whether the abundance of MP at the sea surface decreases with distance from land-based sources, e.g., river mouths, harbors, and submarine wastewater outfalls. The sea surface was sampled with a manta trawl to examine the abundance, composition, and distribution of floating MPs, and Generalized Additive Mixed Models (GAMMs) were performed to examine the relationship between MP abundance (particles km−2) and the distance to putative sources. MPs were found in all 57 net tows, with an average of ⁓120,000 MP km−2 and maximum values of ⁓1,500,000 MP km−2. The composition of MPs was dominated by fragments (>50% of the total count) and over 80% of all MPs were ≥1 mm. The combined effect of the various sources, spatially concentrated in urban areas, makes it difficult to distinguish their relative contributions, but the MP composition suggested that rivers are more important sources, followed by submarine wastewater outfalls and then harbors. A significant and steep negative relationship with the “distance to source” explained 15.2% of the variance of “MP abundance”, suggesting rapid offshore displacement within the HCS. This is the first study to report this pattern along the edges of the South Pacific Subtropical Gyre (SPSG), revealing that continuous offshore transport of microplastic from land-based sources is occurring over large scales and contributing to the accumulation of microplastics in the center of the SPSG. However, the findings additionally suggested that processes at meso- and submeso-spatial scales (driven by geographic and seasonal variables) are disrupting the general pattern.

Effect of ocean outfall discharge volume and dissolved inorganic nitrogen load on urban eutrophication outcomes in the Southern California Bight

Climate change is increasing drought severity worldwide. Ocean discharges of municipal wastewater are a target for potable water recycling. Potable water recycling would reduce wastewater volume; however, the effect on mass nitrogen loading is dependent on treatment. In cases where nitrogen mass loading is not altered or altered minimally, this practice has the potential to influence spatial patterns in coastal eutrophication. We apply a physical-biogeochemical numerical ocean model to understand the influence of nitrogen management and potable wastewater recycling on net primary productivity (NPP), pH, and oxygen. We model several theoretical management scenarios by combining dissolved inorganic nitrogen (DIN) reductions from 50 to 85% and recycling from 0 to 90%, applied to 19 generalized wastewater outfalls in the Southern California Bight. Under no recycling, NPP, acidification, and oxygen loss decline with DIN reductions, which simulated habitat volume expansion for pelagic calcifiers and aerobic taxa. Recycling scenarios under intermediate DIN reduction show patchier areas of pH and oxygen loss with steeper vertical declines relative to a “no recycling” scenario. These patches are diminished under 85% DIN reduction across all recycling levels, suggesting nitrogen management lowers eutrophication risk even with concentrated discharges. These findings represent a novel application of ocean numerical models to investigate the regional effects of idealized outfall management on eutrophication. Additional work is needed to investigate more realistic outfall-specific water recycling and nutrient management scenarios and to contextualize the benefit of these management actions, given accelerating acidification and hypoxia from climate change.

Fuzzy-Based Human Health Risk Assessment for Shallow Groundwater Well Users in Arid Regions

The conventional point-estimate human health risk assessment (HHRA) primarily uses average concentrations of a limited number of samples due to the high monitoring costs of heavy metals in groundwater. The results can be erroneous when concentrations significantly deviate from the average across the collected samples in an investigation region. The present research developed a hierarchical fuzzy-based HHRA (F-HHRA) framework to handle variations in limited data sets and subjectively established a broader range of risks for various exposure groups. Groundwater samples from 80 to 120 m deep in shallow wells were collected from agricultural farms along Wadi Rumah in the Qassim Region of Saudi Arabia. Laboratory testing found total dissolved solids much higher than the promulgated drinking water quality standards. As the aftertaste issue eliminated the raw water potability, the study considered dermal exposure for HHRA. The collected samples were tested for thirteen potential heavy metals (HMs), including barium (Ba), boron (B), cadmium (Cd), chromium (Cr), copper (Cu), iron (Fe), lead (Pb), lithium (Li), manganese (Mn), silver (Ag), strontium (Sr), thallium (TI), and zinc (Zn). Cu, Fe, Pb, Ag, and TI were lower than the detectable limit of the inductively coupled plasma mass spectrometry device. Concentrations of the remaining HMs in wastewater outfalls that were much less than the groundwater eradicated the impact of anthropogenic activities and affirmed natural contamination. Apart from 10% of the samples for Mn and 90% of the samples for Sr, all the other HMs remained within the desired maximum allowable concentrations. Point-estimate and fuzzy-based approaches yielded ‘low’ dermal non-cancer risk and cancer risk for all groups other than adults, where dermal cancer risk of Cr remained in the ‘acceptable’ (1 × 10−6 and 1 × 10−5) risk zone. Although dermal risk does not require controls, scenario analysis established the rationality of F-HHRA for more contaminated samples. The proposed hierarchical F-HHRA framework will facilitate the decision-makers in concerned agencies to plan risk mitigation strategies (household level and decentralized systems) for shallow well consumers in Saudi Arabia and other arid regions.

Changes in community structure and microbiological risks in a small stream after receiving treated shale gas wastewater for two years

Discharge of treated shale gas wastewater is becoming prevalent in the Sichuan Basin in China, and the resulting potential environmental impacts have raised concern. In this study, the responses of microbial community in the receiving water to discharge of treated shale gas wastewater were assessed during a two-year study period, covering two wet seasons and one dry season. The results showed that the discharge of treated shale gas wastewater had no significant effects on alpha diversity in the two wet seasons, but had significant effects in the dry season after 15 months of discharge. Obvious changes in microbial community structure were observed in all three seasons at the downstream sites near the wastewater outfall, as compared to the control site. Multimetric indices indicated that the impacts of wastewater discharge on microbial ecosystem occurred with the extension of the discharge period. Moreover, special attention was given to the microbiological risks associated with antibiotic resistance genes (ARGs), virulence factor genes (VFGs), and pathogenic antibiotic resistant bacteria (PARBs) in the dry season in sediments of the receiving water. At downstream sites near the outfall, five subtypes of ARGs and seven VFGs showed a significant increase in relative abundance. Forty-two PARBs carrying ARGs and VFGs were detected, and three PARBs (Pseudomonas aeruginosa, Pseudomonas stutzeri and Pseudomonas fluorescens) increased obviously in relative abundance at the downstream site near the outfall. In conclusion, long-term wastewater discharge had effects on the microbial community, and limited microbiological risks existed in the receiving waters.

Contamination of the marine environment by Antarctic research stations: Monitoring marine pollution at Casey station from 1997 to 2015.

The contamination of the marine environment surrounding coastal Antarctic research stations remains insufficiently understood in terms of its extent, persistence, and characteristics. We investigated the presence of contaminants in marine sediments near Casey Station, located in the Windmill Islands of East Antarctica, during the period spanning from 1997 to 2015. Metals, hydrocarbons, PBDEs, PCBs, and nutrients were measured in sediments at anthropogenically disturbed sites, including the wastewater outfall, the wharf area, two former waste disposal sites, and various control locations. Sampling was carried out at three spatial scales: Locations, which were generally kilometres apart and formed the primary scale for comparison; Sites, which were 100 meters apart within each location; and Plots, which were 10 meters apart within each site. Consistently higher concentrations of most contaminants, and in some cases nutrients, were observed at disturbed locations. Some locations also exhibited an increase in contaminant concentrations over time. The spatial distribution of sediment properties (such as grain size and organic matter) and contaminants displayed intricate patterns of variation. Variation in grain size depended on the size category, with fine grains (e.g., <63 μm) showing the greatest variation at the Location scale, while coarse grains exhibited minimal variation at this scale. Contaminant levels demonstrated significant differences between Locations, accounting for approximately 55% of the overall variation for metals, while the variation within the 10-meter scale generally exceeded that within the 100-meter scale. Residual variation among replicate samples was also very high, demonstrating the need for adequate replication in studies of sediments and contaminants around stations. Some contaminants exceeded international guidelines for sediment quality, including metals, hydrocarbons, and PCBs. We conclude that Antarctic research stations such as Casey are likely to pose a moderate level of long-term ecological risk to local marine ecosystems through marine pollution. However, contamination is expected to be confined to areas in close proximity to the stations, although its extent and concentration are anticipated to increase with time. Raising awareness of the contamination risks associated with Antarctic stations and implementing monitoring programs for marine environments adjacent to these stations can contribute to informed decision-making and the improvement of environmental management practices in Antarctica.

VARIATION OF SOME WATER QUALITY PARAMETERS OF HUWAIZA MARSH IN SOUTHERN IRAQ

Huwaiza marsh is considered the largest marsh in the southern part of Iraq. It is located between 31° and 31.75° latitude and extends over the Iraqi-Iranian border; but the largest part lies in Iraq. It is located to the east of Tigris River in Messan and Basra governorates.In this research, the variation of some water quality parameters at different locations of Huwaiza marsh were studied to find out its efficacy in the treatment of the contamination coming from the wastewater outfall of Kahlaa brokendown sewage treatment plant which lies on the Kahlaa River. This rive is the main feeder of Huwaiza marsh. Ten water quality sampling locations were chosen in this marsh. The water samples were taken during 2009 for three months; January, April and August representing winter, spring and summer respectively.The results of water quality analyses showed that Kahlaa untreated sewage had a negative impact on the water quality of Huwazia marsh; especially in its upstream region. Analyses of water samples taken from the middle and downstream end of the marsh showed that the marsh water is safe for fishing and swimming in these regions.

Application of Unmanned Aerial Vehicle–Based Infrared Images in Determining Characteristics of Sea Surface Temperature Distribution

This study investigated the temperature field of a body of water by using rotary-wing unmanned aerial vehicles (DJI Mavic 2 Enterprise Dual) comprising visible light and infrared cameras to determine sea temperature distribution. With a flight height of 150 m, image overlap of 80%, and image resolution of 4.75 cm/pixel, the proposed method was more effective than the conventional portable conductivity–temperature–depth device in rapidly measuring sea surface temperature and determining sea temperature distribution. The discharged heated water of the Hoping Power Plant traveled 100–330 m from the wastewater outfall and then gradually diffused in the range of 100–490 m before reaching a similar temperature to the background sea temperature. The diffusion of the thermal plume was mainly affected by regional marine meteorological conditions

The Wastewater Contamination Index: A methodology to assess the risk of wastewater contamination from satellite-derived water quality indicators

One of the major sources of pollution affecting inland and coastal waters is related to poorly treated or untreated wastewater discharge, particularly in urbanized watersheds. The excess of nutrients, organic matter, and pathogens causes an overall deterioration of water quality and impairs valuable ecosystem services. The detection of wastewater pollution is essential for the sustainable management of inland and coastal waters, and remote sensing has the capability of monitoring wastewater contamination at extended spatial scales and repeated frequencies. This study employed satellite-derived water quality indicators and spatiotemporal analysis to assess the risk of wastewater contamination in Conceição Lagoon, a coastal lagoon in Southern Brazil. Using an analytical model, three water quality indicators were derived from Level 2A Sentinel-2 MSI images: the absorption coefficients of chlorophyll-a and detritus combined with coloured dissolved organic matter, and the backscattering coefficient of suspended solids. The temporal standardized anomalies were calculated for each water quality indicator for the period of 2019–2021, and their anomalies during a known outfall event were used to evaluate spatial variation modes. The spatial mode explaining most of the variability was used to estimate weights for the water quality indicators anomalies in a linear transformation that can indicate the risk of wastewater contamination. Results showed that the wastewater spatial mode for this region was characterized by positive anomalies of backscattering coefficient of particulate matter and absorption coefficient of detritus combined with coloured dissolved organic matter, each with a relative importance of 50%. The application of this spatiotemporal analysis was formulated as the Wastewater Contamination Index. With the aid of photographic records, and additional meteorological and water quality data, the results of the index were verified for wastewater outfall events in the study area. The methodology for constructing the proposed Wastewater Contamination Index applies to other locations and can be a valuable tool for operational monitoring of wastewater contamination.

Metagenomes from Coastal Sediments of Kuwait: Insights into the Microbiome, Metabolic Functions and Resistome.

Coastal sediments in the proximity of wastewater and emergency outfalls are often sinks of pharmaceutical compounds and other organic and inorganic contaminants that are likely to affect the microbial community. The metabolites of these contaminants affect microbial diversity and their metabolic processes, resulting in undesirable effects on ecosystem functioning, thus necessitating the need to understand their composition and functions. In the present investigation, we studied the metagenomes of 12 coastal surface sediments through whole genome shot-gun sequencing. Taxonomic binning of the genes predicted about 86% as bacteria, 1% as archaea, >0.001% as viruses and Eukaryota, and 12% as other communities. The dominant bacterial, archaeal, and fungal genera were Woeseia, Nitrosopumilus, and Rhizophagus, respectively. The most prevalent viral families were Myoviridae and Siphoviridae, and the T4 virus was the most dominant bacteriophage. The unigenes further aligned to 26 clusters of orthologous genes (COGs) and five carbohydrate-active enzymes (CAZy) classes. Glycoside hydrolases (GH) and glycoside transferase (GT) were the highest-recorded CAzymes. The Kyoto Encyclopedia of Genes and Genomes (KEGG) level 3 functions were subjugated by purine metabolism > ABC transporters > oxidative phosphorylation > two-component system > pyrimidine metabolism > pyruvate metabolism > quorum sensing > carbon fixation pathways > ribosomes > and glyoxalate and dicarboxylate metabolism. Sequences allying with plasmids, integrons, insertion sequences and antibiotic-resistance genes were also observed. Both the taxonomies and functional abundances exhibited variation in relative abundances, with limited spatial variability (ANOVA p > 0.05; ANOSIM-0.05, p > 0.05). This study underlines the dominant microbial communities and functional genes in the marine sediments of Kuwait as a baseline for future biomonitoring programs.

Recovery trajectories of the bacterial community at distances in the receiving river under wastewater treatment plant discharge

Microbes in rivers are an important part of the biogeochemical cycle in aquatic ecosystems, and understanding the major factors that influence the composition of microbial communities has an important role in assessing and improving ecosystem functioning. A high-throughput 16 S rRNA gene sequencing technique was employed to sequence bacterial communities in 21 sediment samples and 21 water samples from an urban river WWTP (wastewater treatment plant) discharge. A systematic study of changes in bacterial community composition in downstream river sediment and water was conducted. The study found that compared with the bacterial diversity in the natural upstream area of the wastewater outfall, the bacterial diversity in the sediment lower reaches decreased significantly, while the bacterial abundance and diversity in the water increased significantly. The Mantel test and redundancy analysis showed that the downstream distance and physicochemical properties were significantly related to the succession of bacterial communities in the sediment downstream of the WWTP discharge. Among them, TOC (total organic carbon) was the most important factor affecting the change in the bacterial community in the downstream sediment. The physicochemical properties were significantly correlated with the succession of bacterial communities in the water downstream of the WWTP discharge. Among them, TN (total nitrogen), PO43--P (phosphorus phosphate) and TP (total phosphorus) were the main factors that affected the change in the bacterial community in the downstream water. Key taxa in the co-occurrence network at different distances downstream reflected the depth of the effect of the WWTP effluent on the bacterial community. The bacterial community in the lower reaches of the river sediment showed a strong recovery ability under the influence of pollutants, while the bacterial community in the lower reaches of the river water was difficult to recover under the influence of pollutants. In general, pollutants contained in effluent are the key to changing the composition of bacterial communities in the lower reaches of the river, but exogenous bacteria in effluent are not. This study provides a basis for further improving the effluent discharge standards of WWTPs in the future.

Occurrence and ecological risk assessment of antibiotic residues in urban wastewater discharged into the coastal environment of the Persian Gulf (the case of Bandar Abbas).

This is the first attempt to detect antibiotic residues released into the Persian Gulf marine environment. In particular, this study quantifies and assesses the ecological risks of amoxicillin (AMX) and azithromycin (AZM) residues in wastewater outfalls from Bandar Abbas, one of the major coastal cities in southern Iran. The wastewater effluent samples were collected from two main wastewater discharging stations, Gursuzan and Suru, between December 2020 and February 2021. High-performance liquid chromatography (HPLC) analysis revealed the average concentration (± 95% CL) of AMX were 460 ± 230.0μg L-1 and 280 ± 100.6μg L-1 in Gursuzan and Suru stations. Mean AZM concentrations were also 264 ± 10.59μg L-1 and 295 ± 89.75μg L-1 in these stations, respectively. Pooled data indicated that there are 335.17 ± 105.11 and 288.17 ± 37.94μg of AMX and AZM residues in the wastewater per liter. The values of potential ecological risk, hazard quotient (HQ), were extensively above 10 (AMX: 90,586.5 and AZM: 5541.7) which suggest that these substances have a high health risk for the ecosystem and public. Given that Bandar Abbas wastewater treatment plant (WWTP) outlets are discharged at about 500 to 700 L s-1, the daily maximum potential AMX and AZM released were estimated to be 19.05 (± 0.283) × 103 and 14.74 (± 0.113) × 103gday-1, respectively (α = 0.05). Our findings show that there is a concerning volume of antibiotic residues released into the northern Persian Gulf, and hence urgent policies and actions are necessary to reduce this pollution.

Excavation of Medieval Partick 2016

GUARD Archaeology Ltd were commissioned by Scottish Water to undertake an archaeological watching brief during ground works associated with the installation of a waste water outfall and associated Combined Sewer Outflow (CSO) as part of development works at Castlebank Street, Partick. Earlier adjacent archaeological works had identified a large ditch and sandstone well on the periphery of the area to the south-west ( Green 2019 ). The archaeological watching brief included the initial monitoring of borehole drilling, expanding to all overburden stripping along the full length of the working area for the drainage tract as well as the adjacent CSO area, stretching from the existing River Kelvin's edge to the boundary of Castlebank Street. The works identified the remaining extent of previously identified features, along with a wide range of further features of interest. These consisted of several distinct phases of structural stonework and two substantial intersecting ditches; a substantial assemblage of pottery was also recovered, along with several metal objects including a medieval decorative pin and a copper alloy decorative boss. The stonework likely relates to the seventeenth century Hutcheson's tower house, with some of the earlier deposits, pottery and metal objects possibly originating from activity around the earlier twelfth century Bishops' residence. Bore hole monitoring was undertaken in early 2016, while overburden stripping and archaeological excavation took place between February and August 2016.

Potential health effects of contaminant mixtures from point and nonpoint sources on fish and frogs in the New Jersey Pinelands

Aquatic ecosystems convey complex contaminant mixtures from anthropogenic pollution on a global scale. Point (e.g., municipal wastewater) and nonpoint sources (e.g., stormwater runoff) are both drivers of contaminant mixtures in aquatic habitats. The objectives of this study were to identify the contaminant mixtures present in surface waters impacted by both point and nonpoint sources, to determine if aquatic biota (amphibian and fish) health effects (testicular oocytes and parasites) occurred at these sites, and to understand if differences in biological and chemical measures existed between point (on-stream) and nonpoint sources (off-stream). To accomplish this, water chemistry, fishes, and frogs were collected from 21 sites in the New Jersey Pinelands, United States. Off-stream sites consisted of 3 reference and 10 degraded wetlands. On-stream sites consisted of two reference lakes and six degraded streams/lakes (four sites above and two sites below wastewater outfalls). Surface water was collected four times at each site and analyzed for 133 organic and inorganic contaminants. One native and five non-native fish species were collected from streams/lakes and native green frogs from wetlands (ponds and stormwater basins). Limited differences in contaminant concentrations were observed in reference and degraded wetlands but for streams/lakes, results indicated that landscape alteration, (upland agricultural and developed land) was the primary driver of contaminant concentrations rather than municipal wastewater. Incidence of estrogenic endocrine disruption (intersex) was species dependent with the highest prevalence observed in largemouth bass and black crappie and the lowest prevalence observed in green frogs and tessellated darters. Parasite prevalence was site and species dependent. Prevalence of eye parasites increased with increasing concentrations of industrial, mycotoxin, and cumulative inorganic contaminants. These findings are critical to support the conservation, protection, and management of a wide range of aquatic species in the Pinelands and elsewhere as habitat loss, alteration, and fragmentation increase with increasing development.

Flow structures and circulation due to meandering geometry in a stratified sea strait

Combining with local topography (i.e., the presence of a bar or a sill on the bottom and the shape of the coastline), the meandering geometry of straits, which have more complex geomorphological formations compared to rivers, reveals different circulation patterns in the coastal region and central part of the strait. Identifying circulation patterns in meanders is crucial to managing those waterways in several aspects (i.e. monitoring the transport of contamination, wastewater outfall, etc.). In the present study, the flow circulations in some meanders of a strait (the Bosphorus), which presents a two-layered flow, are analyzed using the calibrated 3D model. Each of the four selected meanders has a unique shape: 1) expansion on both sides, 2) expansion on one side, 3) with a constant width, and 4) an estuary connected from one side.The results showed the decisive role of some characteristic morphological formations (i.e. headland, bars on the bottom, the shape of coastline) in creating reversing flow in a meander rather than adverse along channel pressure gradient due to the sudden expansion. While extreme water level differences between both entrances of the strait reveal unidirectional flow in the main channel, the reversals may develop in the shallowness of the meanders depending on the coastline shape (e.g. smoothness), presence of a local bar, and the presence of a headland. Besides this, in the case of a meander that has expansion at both sides, the flow separates from the main channel and circulates in opposite direction either clockwise or counterclockwise in the expanded sections. The annual flow profiles show a notable difference between the main channel and the coastal part of the meanders for a significant amount of time. For the low composite Froude numbers (G2) around or less than 0.3, the main channel flow is two-layered with the upper layer flowing south and the lower layer flowing north. In the shallowness of the expansions, however, it is unidirectional. For higher G2s (> 0.6), however, it is unidirectional both in the main channel and in the expansions of the meanders.

Influences of Elevated Nutrients and Water Temperature from Wastewater Effluent on River Ecosystem Metabolism

River ecosystem metabolism (REM) is a measure of ecological function which integrates gross primary production (GPP) and ecosystem respiration (ER). Urban rivers often receive effluents from wastewater treatment plants (WWTP) which frequently alter nutrient concentrations and modify temperature regimes of receiving water bodies. To investigate how variations in nutrients and water temperature affect REM, we applied the night-time slope modelling to estimate diurnal REM at sites above and below a wastewater outfall on the River Wandle, UK. Overall, estimated GPP (0–21.2 mgO2·L− 1·d− 1) and ER (5.5–10.1 mgO2·L− 1·d− 1) from our study sites were similar to those of urban impacted rivers in other countries. GPP values were similar between sites, but downstream ER values were significantly higher affected by the WWTP effluent. GPP/ER ratios were < 1 indicating heterotrophic conditions and the river as a carbon source during the study. We found that sites had similar activation energy associated with ER suggesting our work provides a useful reference for estimating temperature corrected metabolic processes for other urban rivers in the region. Furthermore, structural equation modelling revealed that nutrient supply, water temperature and light availability were the main factors driving REM. This research highlights the major environmental factors affecting REM, which helps to understand the response of river metabolism and river regulation of regional carbon cycle to future climate change and provide evidence to inform river restoration and future in-stream management.