Sewage Outfall Research Articles

Impact of point source pollutants on the distribution of selected water parameters in the Vistula River in Puławy, Poland

Human activities have a complex and multidimensional impact on water quality. The concentration of inhabitants, production and services intensifies influence of urban agglomerations on water in rivers. Among many sources of surface water pollution, the most important are sewage discharges. The aim of the research was to determine the effect of point discharge of treated industrial and municipal wastewater on the distribution of selected water chemical parameters in the Vistula River in Puławy. The studies were carried out in 2018–2019. Samplings were collected in five sampling points and tested in the hydrochemical laboratory. The obtained data were statistically analysed to investigate differences between the sampling points. The negative impact of wastewater discharge on the water quality in the Vistula was found. However, the pollution level decreased with the flow of the river. The parameters tested at measurement point located 1200 m below the discharge approached the values recorded above the sewage outfall. The presented observations of changes in the concentration of pollutants indicate the self-purification capacity of a river. However, for each watercourse flowing through urbanized areas, it is an individual feature. It depends on a number of factors and requires regular monitoring studies taking into account hydrochemical analysis of watercourses.

Brumadinho Health Project: food and nutrition insecurity versus socioeconomic statuses and dimensions of the food system after the dam rupture.

To describe the situation of food insecurity of families according to the socioeconomic characteristics and dimensions of the food system in Brumadinho, state of Minas Gerais, Brazil, after the dam rupture in Córrego do Feijão mine. This is a descriptive study focused on households carried out from the baseline of the Brumadinho Health Project. Food insecurity, the main outcome, was assessed by the short version of the Brazilian Food Insecurity Scale. Other investigated variables were: socioeconomic data; geographic stratum of the households; family's assets; income; expenses; cultivation of food and animal husbandry for consumption. Descriptive analyses were performed comparing the food insecurity of the household according to the other variables by the χ2 test to compare the proportions. Of the investigated households (n=1,441), 35.1% were facing food insecurity. facing food insecurity had: lower prevalence of masonry households with coating (91.4%; 95%CI 87.7%-94.1% vs. 96.7%; 95%CI 94.9%-97.8%); highest proportion of rudimentary cesspit (16.9%; 95%CI 13.3%-21.2% vs. 9.4%; 95%CI 7.4-11.9); lower prevalence of own and paid-off homes (63.9%; 95%CI 56.8-70.5 vs. 77.3%; 95%CI 72.3-81.7); and income reduction after the dam rupture (33.0%; 95%CI 27.1-39.6 vs. 14.1%; 95%CI 11.2-17.6), when compared with those in a food security situation. The prevalence of food insecurity was high, with report of a reduction in household income after the dam rupture. Moreover, most of the households had worse structural quality and sewage outfall. These results evidence the vulnerability of families and possible violation of the human right to adequate food, denoting the urgency of continuous reparative actions.

Rejuvenation and Beautification of River and Nala

Nowadays almost all water bodies in India are getting more and more polluted and facing with three major problems which are likely to be Untreated Sewage, Solid waste and abetting encroachment or slums areas along the bank of River, nala or any water body. Due to population development, outdated storm water drainage systems, climate change, and poor management of utility infrastructures, significant damage has recently been done to urban areas, including Hyderabad City, the capital of Telangana. One of the most practical methods to manage these complex urban systems is using process of Rejuvenation of the Nala and pollution abetment works by diverting the incoming Sewage leading to Nala in the Designed Sewerage Systems. In this research work, the framework is prepared for Rejuvenation of Polluted Nala channel and Designing Sewerage System for sewage outfall from the abetting slums including effective management of the nala system. This study is divided into three main parts which consists of 1. Contribution of Upstream Catchment area-Determination of the contribution of Catchment flow from Upstream to Confluence point of Nala and delineation of the Catchment area. 2. Nala Channelization- The Inlet flow has been intercepted and diverted to STP and total carrying capacity of Nala is found and check has been determined. 3. Design of Sewerage System- Determining the Sewage flow generation beside the Nala and four Inlets joining the Nala. For the first stage various Design Software like Civil 3D, Power Civil, Infraworks were used to simulate the existing catchment flow leading at the Confluence point then by using capabilities of QGIS 3.16.11 software application the Drainage networks, stream orders and elevation details has been achieved. In the Second stage the carrying capacity of storm water Nala is been determined by making calculation check for total of upstream flow, storm water flow and Inlet flows. Finally the third stage determines the generation of Sewage flow tapping and diverting it to the Sewer System by Designing and optimizing it in SewerGEMs select-series 4 Software which will get carried to the Sewage Treatment Plants, thereby treating the water as per CPCB-NGT norms. The proposed strategic approach is able to abate the pollution in Nala, maintain the ecological flow and conserve the public realm along the river.

CAUSES AND CONSEQUENCES OF RIVER POLLUTION: AN EXPLORATORY STUDY ALONG THE TURAG RIVER AREA, TONGI, BANGLADESH

Turag, among all the rivers, is vital lifeblood for the metropolis of Dhaka. This study was carried out to investigate the vital causes of Turag River pollution and subsequent consequences for local inhabitants. The data for this exploratory study were gathered through qualitative analysis and a review of the relevant literature. Field visits were conducted, and relevant data were gathered through individual in-depth interviews (IDIs, N=70), focus group discussions (FGDs, N=02), and researcher observations combined with transect walk along the adjacent areas. The investigation discovered various causes of pollution in the Turag River, the two most significant of which are industrial effluents along with municipal and illegal residential sewage outfalls that release directly into the river. Likewise, abundant different types of garbage, fecal excrement, pesticides from nearby agricultural land, slaughterhouse wastes, spills from a variety of water vehicles, and other human activities such as housing projects and brickfield construction contribute to Turag water pollution. Manifest evidence has been found regarding the consequences of Turag River pollution having of dark color and perilous odor of the Turag River water; local people suffering from diseases such as allergy, skin infection, cold cough, diarrhea, dysentery, hepatitis, typhoid, respiratory problem, and various others; impact on aquatic lives, fisheries, and livestock; reduced agricultural production; shifts in occupational status; breeding ground for mosquitoes; and many more. This study provides a thoughtful perspective on the origin of Turag River pollution and its various repercussions on riverine communities. To reduce pollution from diverse sources, efforts should be made to decrease the concentration of contaminants.

Putative Invertebrate, Plant, and Wastewater Derived ssRNA Viruses in Plankton of the Anthropogenically Impacted Anacostia River, District of Columbia, USA.

The Anacostia River is a highly impacted watershed in the Northeastern United States which experiences combined sewage outfall in downstream waters. We examined the composition of RNA viruses at three sites in the river using viral metagenomics. Viromes had well represented Picornaviruses, Tombusviruses, Wolframviruses, Nodaviruses, with fewer Tobamoviruses, Sobemoviruses, and Densoviruses (ssDNA). Phylogenetic ana-lyses of detected viruses provide evidence for putatively autochthonous and allochthonous invertebrate, plant, and vertebrate host origin. The number of viral genomes matching Ribovaria increased downstream, and assemblages were most disparate between distant sites, suggesting impacts of the combined sewage overflows at these sites. Additionally, we recovered a densovirus genome fragment which was highly similar to the Clinch ambidensovirus 1, which has been attributed to mass mortality of freshwater mussels in Northeastern America. Taken together, these data suggest that RNA viromes of the Anacostia River reflect autochthonous production of virus particles by benthic metazoan and plants, and inputs from terrestrial habitats including sewage.

Anthropogenic effects on the marine environment adjacent to Palmer Station, Antarctica

AbstractLocalized contamination from research-related activities and its effects on macrofauna communities in the marine environment were investigated at Palmer Station, a medium-sized Antarctic research station. Relatively low concentrations of polycyclic aromatic hydrocarbons (PAHs; 32–302 ng g-1) and total petroleum hydrocarbons (TPHs; 0.9–8.9 μg g-1) were detected in sediments adjacent to the sewage outfall and pier, where most human activities were expected to have occurred, and at even lower concentrations at two seemingly reference areas (PAHs 6–30 ng g-1, TPHs 0.03–5.1 μg g-1). Elevated concentrations of PAHs in one sample taken in one reference area (816 ng g-1) and polychlorinated biphenyls (353 ng g-1) and dichloro-diphenyl-trichloroethane (3.2 and 25.3 ng g-1) in two samples taken adjacent to the sewage outfall indicate spatial heterogeneity of localized sediment contamination. Limpet (Nacella concinna) tissues collected adjacent to Palmer Station had high concentrations of PAHs, copper, lead, zinc and several other metals relative to outlying islands. Sediment and limpet tissue contaminant concentrations have decreased since the early 1990s following theBahía Paraísospill. Natural sediment characteristics affected macrofaunal community composition more than contamination adjacent to Palmer Station, presumably because of the low overall contamination levels.

Design for large-scale maricultures of the Mediterranean demosponge Chondrosia reniformis Nardo, 1847 for collagen production

To support the use of marine demosponges for collagen production in integrated culture settings, we investigated a low–cost, easily applicable and sustainable production method for the culture of Chondrosia reniformis Nardo, 1847 (Demospongiae, Chondrosiida, Chondrosiidae). Novel methods were tested to culture this collagen-rich demosponge in three consecutive trials, during which recovery, survival and growth rates of explants were monitored cultured within a site with organic pollution site (urban water discharge) and a pristine site. During Culture Trial 1, orientation of the culture plates had a significant main effect on growth rates of glued explants, with vertically mounted explants showing faster growth compared to horizontal ones (range 63 ± 46% to 116 ± 54%). However, vertically glued explants detached more compared to horizontal ones (30% versus 7%), which was not the case for nailed explants where only 3% detached regardless of orientation. Thus, vertically nailed explants yielded overall highest success rates. An interactive effect of substrate and attachment method on sponge growth rates was also found: glued sponges growing faster on PVC and polypropylene (PP) as compared to iron as substrate, for nailed sponges no growth differences were found between substrates. During Trial 2, no growth differences between sites or orientation were found, although similar to Trial 1, vertically cultured explants showed higher detachment rates (40–52%) and lower survival Based on to the results of Trials 1 and 2, the combination PP/nail/horizontal was ultimately selected for scale up in Trial 3, with explants as well as colonies. Culture Trial 3 revealed survival rates of 75–92% for explants and 83–100% for colonies after 467 days of culture. Growth rates were similar at the polluted and pristine sites for both explants facing up/down (range 126 ± 99% to 218 ± 139%) and colonies (range 128 ± 60% to 226 ± 325%). These consecutive culture trials spanning 2 years yielded consistent growth rates and high survival rates over 1 year of culture, both under pristine and polluted conditions. We here report the successful culturing method for a collagen production pipeline using C. reniformis. The final ‘Demosponge lantern’ design, is simple, sustainable, enhances productivity and is adaptable to seawater environments combined with sources of variable organic particle load such as fish culture or sewage outfall.

Detection of SARS-CoV-2 in urban stormwater: An environmental reservoir and potential interface between human and animal sources

While wastewater has been found to harbor SARS-CoV-2, the persistence of SARSCoV-2 in stormwater and potential transmission is poorly understood. It is plausible that the virus is detectable in stormwater samples where human-originated fecal contamination may have occurred from sources like sanitary sewer overflows, leaky wastewater pipes, and non-human animal waste. Because of these potential contamination pathways, it is possible that stormwater could serve as an environmental reservoir and transmission pathway for SARS-CoV-2. The objectives of this study are: 1) determine whether the presence of SARS-CoV-2 could be detected in stormwater via RT-ddPCR (reverse transcription-digital droplet PCR); 2) quantify human-specific fecal contamination using microbial source tracking; and 3) examine whether rainfall characteristics influence virus concentrations. To accomplish these objectives, we investigated whether SARS-CoV-2 could be detected from 10 storm sewer outfalls each draining a single, dominant land use in Columbus, Xenia, and Springboro, Ohio. Of the 25 samples collected in 2020, at minimum one SARS-CoV-2 target gene (N2 [US-CDC and CN-CDC], and E) was detected in 22 samples (88%). A single significant correlation (p = 0.001), between antecedent dry period and the USCDC N2 gene, was found between target gene concentrations and rainfall characteristics. Grouped by city, two significant relationships emerged showing cities had different levels of the SARS-CoV-2 E gene. Given the differences in scale, the county-level COVID-19 confirmed cases COVID-19 rates were not significantly correlated with stormwater outfall-scale SARS-CoV-2 gene concentrations. Countywide COVID-19 data did not accurately portray neighborhood-scale confirmed COVID-19 case rates. Potential hazards may arise when human fecal contamination is present in stormwater and facilitates future investigation on the threat of viral outbreaks via surfaces waters where fecal contamination may have occurred. Future studies should investigate whether humans are able to contract SARS-CoV-2 from surface waters and the factors that may affect viral longevity and transmission.

Biological effects of the antihypertensive losartan under different ocean acidification scenarios

Since the last decade, several studies have reported the presence and effects of pharmaceutical residues in the marine environment, especially those of the antihypertensive class, such as losartan. However, there is little knowledge about the physiological effects of losartan in marine invertebrates regarding its behavior under possible coastal ocean acidification scenarios. The objective of this study was to evaluate biological effects on marine organisms at different levels of the biological organization caused by the compound losartan in water and sediment under coastal ocean acidification scenarios. Water and sediment samples were collected at five sites around the Santos Submarine Sewage outfall (SSO) and two sites around the Guarujá Submarine Sewage Outfall (GSO). Losartan was found in concentrations ranging from <LOD to 7.63 ng/L in water and from <LOQ to 3.10 ng/g in sediments. Statistical analysis showed interactive effects pH and losartan on the toxicity results. The water toxicity test with Echinometra lucunter embryos/larvae showed LOECs 50–100 mg/L, with values decreasing as the pH decreased. In the sediment assays, LOEC value for sea urchin embryo-larval development was 1.0 μg/g for all tested pHs. Regarding the lysosomal membrane stability assays with adult bivalves, a LOEC of 3000 ng/L was found for Perna perna in water exposure (both at pH 8.0 and 7.6). Effects for Mytella guyanensis were observed at environmentally relevant concentrations in sediment (LOEC = 3 ng/g at pH 8.0 and 7.6). This study demonstrated that coastal ocean acidification by itself causes effects on marine invertebrates, but can also increase the negative effects of losartan in waterborne exposure. There is a need to deepen the studies on the ecotoxicity of pharmaceutical residues and acidification of the marine environment.

Organic contaminants in marine environment - Let us not forget the shallow areas

The evaluation of anthropogenic pressures in marine environments commonly involves sediments, water and marine biota. However, the evaluation of the quality of the beach sediment and sediments from shallow areas are scarce compared to sediments from deeper areas in environmental assessment studies. In this study polycyclic aromatic hydrocarbons and linear alkylbenzenes were assessed in sediments from shallow areas of the São Sebastião channel, southeastern Brazil. The channel is part of the Marine Protected Area of the Northern Coast of São Paulo State besides holds the largest petroleum terminal in South America further than three sewage outfalls. Despite the concentrations of these contaminants in the sediments were relatively low compared to those found in the sediments from deeper areas of the channel, suggesting low toxicity of the beach sediments, the contamination reflected the pattern of the sediments of the São Sebastião channel.

Assessment of the water and sediments quality around the coastal submarine sewage outfall in Guarujá, São Paulo, Brazil

The discharge of domestic sewage is one of the most common types of marine pollution, namely through submarine outfalls. In this study, water and sediments of the coastal submarine sewage outfall in Guarujá, São Paulo, Brazil were assessed during the high (January) and low (April) tourist seasons in 2018. The Canadian Council of Ministers of the Environmental Water Quality Index (CCMEWQI) showed a “marginal” water quality, in both seasons, where dissolved oxygen, biochemical oxygen demand, oil and greases, ammonia, surfactants, aluminium, lead, copper, nickel, Escherichia coli and Enterococci showed potential ecological risks. However, no mutagenic potential was detected in the complex mixture (Ames Salmonella/microsome test: MI&lt;2), and no protozoa and Salmonella bacteria were found. In the sediment, a total of 25 benthic taxa were inventoried, suggesting that the macrofauna is not under contamination stress. Cadmium, lead, copper, chromium, nickel and zinc were below the Threshold Effect Level, and the Geoaccumulation Index was &lt;0. Furthermore, the absence of acute toxicity to the test organism Kalliapseudes schubartii (EC50: 96h) and the Shannon-Wiener diversity index (H’: 2.5 to 3.5 bits/ind) suggests healthy or unpolluted environments. However, the deviation of some environmental indicators suggests the need of continuous monitoring based on field measurements.

Study on layout optimization of sewage outfalls: a case study of wastewater treatment plants in Xiamen

In order to protect the offshore environment and strengthen the comprehensive rectification of sewage outfalls, an evaluation method of regional sewage outfalls by combining the marine numerical simulation and comprehensive evaluation technology was constructed, considering the marine environmental capacity and the ecological impact of sewage discharge from outfalls on the marine eco-environment sensitive areas. Then the layout rationality of each outfall was evaluated and the discharge scale was optimized with a case study of existing sewage outfalls in Xiamen. The results show that, the comprehensive evaluation score of Yundang outfall was 3 points in 2025, evaluated as the outfall with irrational layout. In 2035, the comprehensive evaluation scores of Fenglin and Dalipu outfalls were 3 and 2 points respectively, evaluated as the outfall with irrational discharge scale. It is suggested to control the scale of expansion or increase the reclaimed water reuse rate in Jimei and Gaoqi Wastewater Treatment Plants. This method has enriched the evaluation system for layout optimization of sewage outfalls, providing scientific supports for comprehensive improvement of sewage outfalls and marine environmental management.

Pathological conditions of the sentinel bivalve, the little mussel Brachidontes rodriguezii, from contaminated intertidal sites in the Southwestern Atlantic coast

A survey of pathological conditions affecting the natural beds of the dominant bivalve species of the intertidal rocky coasts of the Southern Atlantic Ocean, was performed. Samples of the little mussel (n = 992), Brachidontes rodriguezii, which is considered a sentinel species, were collected from seven sites that present different anthropogenic activity (low anthropogenic activity, harbor, and sewage waste) along the Argentinean coast, and processed by standard histological techniques. Our results showed for the first time in a B. rodriguezii population from Mar del Plata harbor a bacterium causing cellular lysis of the spermatogenic cells (6.5% of prevalence) and in a population from Villa Gesell, a site with low anthropogenic activity, one little mussel presented cytoplasmic vacuoles in the oocytes’s cytoplasm similar to a microsporidian (0.2% of prevalence). A ciliated protozoan parasitizing the cytoplasm of the epithelial digestive tubules and larval stages of two different digenean parasites, was found infecting the little mussel from both contaminated and uncontaminated sites. Sporocysts of the family Bucephalidae invaded the gonad, causing severe gonadal damage including castration, and gymnophallid metacercariae located between the mantle and shell or embedded in the mantle tissues, occupied the gonadal space.In Punta Carballido, a site located next to a sewage outfall, the highest prevalence of infection was found, for the ciliated protozoan in the digestive tubules (5.1%) and for the digenean parasites (bucephalid sporocyst 24.4%, and gymnophallid metacercariae 50%). Moreover, we found a positive correlation between shell length and overall prevalence of parasites.

Discussion on the Selection and planning of Sewage Outfall Into the sea—a case of Gaoqi Sewage Treatment Plant

Scientific selection of the sewage outfall into the sea plays an important role in rational utilization of Marine self-purification capacity, reduction of land sewage discharge and ecological risk, and protection of the Marine environment. In this paper, the selection and layout of the sewage outfall into the sea of Gaoqi sewage treatment plant is taken as an example. First, the primary sewage outfall is selected according to the sewage outlet selection and delimiting principle. Then, the hydrodynamic and water quality model is established to predict and analyse the effects of sewage discharge from each primary outfall on marine water quality and sensitive areas of ecological environment. Finally, the final discharge outfall is determined by considering the environmental impact, engineering economic conditions. The results show that the recommended scheme is in line with the Marine function zoning, with good pollutant diffusion conditions, far away from the ecologically sensitive areas, and with the minimum project investment.

Copepods community structure and function under oceanographic influences and anthropic impacts from the narrowest continental shelf of Southwestern Atlantic

Studies on the Copepod community structure and function under oceanographic influences and anthropic impacts was carried out in the narrowest continental shelf of Brazil. A total of 65 taxa were identified, of which 39 were Calanoida. The most abundant species was Temora turbinata (65.26%) followed by Centropages velificatus, Paracalanuspavus, Undinula vulgaris and Clausocalanus furcatus. A mixture of coastal and oceanic species of Copepods was registered being difficult to separate both populations, however predominated the oceanic species due the narrow shelf and low influence of rivers flux. The frequency of occurrence showed that 24.62% of the species were constants, 13.85% accessories and 61.53% were accidentals. A diversity and abundance gradient were registered from neritic to oceanic waters, however diversity was very low to a shelf area under oceanic influence. The narrow shelf from the studied area permitted the movement of oceanic copepods to coastal areas. The reduced density was caused by the oligotrophic characteristic of the Tropical Water mass present in the area; however, the very low diversity was possibly caused by anthropic impacts (sewage outfalls), mainly in stations closer to the continent. Calocalanus pavo, Undinula vulgaris and Temora stylifera were the best indicators of the area and they were associated to phytoplankton abundance. The Copepod functional traits analyzed presented two sets separated by the reproductive behavior, the biggest set grouped small broadcasters, filter feeders mostly with an omnivore–herbivore strategy and a smaller group, sac-spawner that carry their eggs until hatching. The present study observed that the anthropogenic inputs had a great influence on copepods species and distribution, causing a different dominance pattern between nearshore and offshore.

Potential threat of SARS-CoV-2 in coastal waters

A novel coronavirus (SARS-CoV-2) has caused more than 150 million confirmed infections worldwide, while it is not clear whether it affects the coastal waters. This paper proposed a biophysical model based on 16 scenarios with different virus half-life parameters to assess potential viral contamination from 25 municipal sewage outfalls into the Bohai Sea. Viral concentration maps showing spatial and temporal changes are provided based on a biophysical model under multiple scenarios. Results demonstrate that adjacent sea areas can become exposed to SARS-CoV-2 via water-borne transport from outfalls, with a higher risk in winter, because SARS-CoV-2 can be highly stable at low temperature. As coastal waters are the ultimate sink for wastewater and the epidemic will last for long time, this work is of great importance to raise awareness, identify vulnerable areas for marine mammals, and avoid the risk of exposure of tourists at bathing beach.

Novel method for industrial sewage outfall detection: Water pollution monitoring based on web crawler and remote sensing interpretation techniques

Sewage outfalls are the ideal locations for water pollution monitoring as they are the final gate that pollutants must pass before entering rivers and oceans. Strengthening the supervision and control of industrial sewage outfalls has become the most important task in water pollution control. Most rivers in China are highly polluted, especially those flowing through cities. It is difficult to investigate, monitor, trace, and remediate sewage outfalls because information regarding the distribution of sewage outfalls into rivers is incomplete and the existing methods of monitoring sewage outfalls into rivers are outdated. This paper proposes an innovative method for feasible and efficient acquisition of sewage outfall data through a combination of web crawler and remote sensing interpretation technologies, employing data from the Luan River Basin as a testing site. We crawled industrial information and spatial location data on the Internet and obtained the locations of industrial sewage outfalls by interpreting remote sensing images. We modeled the distribution of sewage inflow from major industries into the tributaries of the Luan River Basin. We verified the accuracy and reliability of the developed method by comparing its results with actual data collected during our field investigation. Sample field tests confirmed the high accuracy (89%) of the proposed method, indicating its successful application in the Luan River Basin. We believe that the proposed method can be used to verify and supervise sewage outfalls in other locations in the future, especially owing to its improved acquisition system, which ensures feasible and efficient measurements without the need for manual investigation. This study provides a scientific basis for decision-making with regard to sustainable development.

Reduced Bacterial Counts from a Sewage Treatment Plant but Increased Counts and Antibiotic Resistance in the Recipient Stream in Accra, Ghana-A Cross-Sectional Study.

Wastewater treatment plants receive sewage containing high concentrations of bacteria and antibiotics. We assessed bacterial counts and their antibiotic resistance patterns in water from (a) influents and effluents of the Legon sewage treatment plant (STP) in Accra, Ghana and (b) upstream, outfall, and downstream in the recipient Onyasia stream. We conducted a cross-sectional study of quality-controlled water testing (January–June 2018). In STP effluents, mean bacterial counts (colony-forming units/100 mL) had reduced E. coli (99.9% reduction; 102,266,667 to 710), A. hydrophila (98.8%; 376,333 to 9603), and P. aeruginosa (99.5%; 5,666,667 to 1550). Antibiotic resistance was significantly reduced for tetracycline, ciprofloxacin, cefuroxime, and ceftazidime and increased for gentamicin, amoxicillin/clavulanate, and imipenem. The highest levels were for amoxicillin/clavulanate (50–97%) and aztreonam (33%). Bacterial counts increased by 98.8% downstream compared to the sewage outfall and were predominated by E. coli, implying intense fecal contamination from other sources. There was a progressive increase in antibiotic resistance from upstream, to outfall, to downstream. The highest resistance was for amoxicillin/clavulanate (80–83%), cefuroxime (47–73%), aztreonam (53%), and ciprofloxacin (40%). The STP is efficient in reducing bacterial counts and thus reducing environmental contamination. The recipient stream is contaminated with antibiotic-resistant bacteria listed as critically important for human use, which needs addressing.

The state of persistent organic pollutants in South African estuaries: A review of environmental exposure and sources

The long-term health of many South African estuaries is impacted by pollutants entering these systems through industrial and agricultural runoff, sewage outfalls, contaminated storm water drainage, flows from informal settlements, and plastic materials in marine debris. Uncontrolled inputs combined with poor environmental management often result in elevated levels of persistent organic pollutants (POPs) in affected estuaries. Data on POPs research from 1960 to 2020 were analysed in terms of their sources, environmental investigations, and health implications. The outcome showed polychlorinated biphenyls (PCBs) and per- and poly-fluoroalkyl sulphonates (PFASs) to exceed the US EPA health advisory levels for drinking water. Concentration of organochlorine pesticides (OCPs) in water were below the WHO limits, while those in fish tissues from most estuaries were found to be below the US FDA limits. Although environmental compartments in some estuaries (e.g. Rooiels and uMngeni estuaries) seem to be less contaminated relative to other marine systems around the world, many others were polluted and critically modified (e.g. Durban Bay, Swartkops, Sundays, and Buffalo systems). Due to inconsistent monitoring methods coupled with limited data availability, temporal trends were unclear. Of the 290 estuaries in South Africa, 65 were prioritised and recommended for POPs evaluation based on their pollution sources, and a monitoring strategy was defined in terms of sampling. Government policies to curb marine pollution need to be enforced to prevent chronic contamination that leads to water quality deterioration and loss of ecosystem services.

Between Natural and Anthropogenic Coastal Landforms: Insights from Ground Penetrating Radar and Sediment Analysis

Both natural and anthropogenic coastal landforms characterize Penang Island. As years have passed it is a challenge to differentiate the genuineness of landmasses created by natural geological formations or by coastal reclamation projects. An account is given of the environmental impact of solid wastes used for reclaiming land in coastal areas of Penang and of the impact of a major sewage outfall in the western channel. Leaching of heavy metals was shown to be one of the main sources of contamination from solid wastes. This paper presents eight lines of ground penetrating radar (GPR) surveys and sediment analysis to identify the anthropogenic interventions that shaped the urban landscape of Penang Island by excavations, filling, and embankment construction along the coastline and differentiate it from the natural one. The surveys were implemented in two locations, the Batu Ferringhi area, representing the natural coastline, and Persiaran Bayan Indah (the Queensbay Mall area), representing the anthropogenic coastal landform. The apparent depth of penetration that was achieved using a 250-MHz antenna is limited (less than 5 m). The results show between natural and anthropogenic sediment recorded different radar facies. In complement mode, mean grain size distribution, sorting, skewness, and kurtosis graphics of sediment samples from both sites correspond with the GPR data. This technique can likely be applied to the developing coast, where natural and anthropogenic coastal landform data is incomplete, considering future coastline development.