Thames Water's Experiences with Cryptosporidium

1991 ◽  
Vol 24 (2) ◽  
pp. 21-26 ◽  
Author(s):  
Madeline Poulton ◽  
Jennifer Colbourne ◽  
P. J. Dennis
Keyword(s):  
Drinking Water ◽  
Surface Water ◽  
Agricultural Land ◽  
Sewage Treatment ◽  
Medical Advice ◽  
Expert Committee ◽  
Cryptosporidium Oocysts ◽  
Pass Through ◽  
Contamination Events ◽  
The Impact

In February 1989 an outbreak of waterborne cryptosporidiosis associated with contaminated surface water in the upper Thames catchment was identified. Less than 0.01% of the population suffered symptoms sufficient for them to seek medical advice. Nevertheless, the impact of the outbreak on the community and the water undertakers was considerable, and an expert committee was appointed by the Secretary of State for Health to advise on research and measures to control the disease and prevent future waterborne outbreaks. One of the committee's interim recommendations was for the gathering of information on the occurrence of cryptosporidium oocysts in the aquatic environment particularly sources used for abstraction and production of drinking water. The results of monitoring in the River Thames catchment will be discussed particularly in light of observations that peak contamination events occur in rivers which pass through agricultural land but do not receive discharges from sewage treatment works.

scholarly journals Modelling Impacts of a Municipal Spatial Plan of Land-Use Changes on Surface Water Quality—Example from Goriška Brda in Slovenia

Water ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 189 ◽  
Author(s):  
Matjaž Glavan ◽  
Sara Bele ◽  
Miha Curk ◽  
Marina Pintar
Keyword(s):  
Water Quality ◽  
Land Use ◽  
Surface Water ◽  
Land Use Change ◽  
Agricultural Land ◽  
Surface Water Quality ◽  
Erosion Processes ◽  
Phosphorus Loads ◽  
The Impact ◽  
Spatial Plan

Intensive agriculture causes nutrient leaching and accelerates erosion processes, which threatens the good quality status of surface waters, as proposed by the European Union (EU) Water Framework Directive. The purpose of this study was to define the impact of two alternative agricultural land-use change scenarios defined in a Municipal Spatial Plan on surface water quality by using the Agricultural Policy/Environmental eXtender (APEX) model. As experimental area, we chose a small Kožbanjšček stream catchment (1464 ha) situated in the Goriška Brda region in Slovenia. The area, due to favorable conditions for vineyards, is facing increasing deforestation. The change of 66.3 ha of forests to vineyards would increase the sediment, nitrate, and phosphorus loads in the stream by 24.8%, 17.1%, and 10.7%, respectively. With the implementation of vegetative buffer strips as a mitigation measure of the current situation, we could reduce the sediment, nitrate, and phosphorus loads by 17.9%, 11.1%, and 3.1%, respectively, while a combination of the two land-use change scenarios would result in a slight increase of the above-mentioned loads, corresponding to 0.61%, 2.1%, and 6.6%, respectively, compared to the baseline situation. The results confirm that, as we can increase pollution levels with deforestation, we can also reduce water pollution by choosing proper types of land management measures.

Assessment and management of health risks related to the recycling of filter backwash water in drinking water production

2013 ◽  
Vol 8 (2) ◽  
pp. 166-179 ◽  
Author(s):  
J. F. Loret ◽  
L. Cossalter ◽  
S. Robert ◽  
I. Baudin ◽  
M. Conan ◽  
...  
Keyword(s):  
Drinking Water ◽  
Drinking Water Treatment ◽  
Direct Filtration ◽  
Cryptosporidium Oocysts ◽  
Untreated Water ◽  
Drinking Water Production ◽  
The Impact ◽  
By Products ◽  
Filter Backwash Water

Analytical campaigns were conducted on different drinking water treatment lines in order to characterize filter backwash water and assess the impact of recycling this water at the head of the plant. The pollutants identified in this water are essentially in the form of particles. Recycling this water may consequently increase the concentration of parameters such as turbidity, suspended solids, metals from coagulants and protozoa. On the other hand, no release of pesticides nor significant generation of disinfection by-products was observed during filter backwash with chlorinated water, in the conditions applied in France for chlorination. A modeling approach based on the mass balance of Cryptosporidium oocysts was applied to estimate the impact of recycling on oocysts concentration in the inlet water. A risk of infection was then assessed for each recycling scenario. A similar approach was also applied for amoebae, which have the capacity to colonize filter media, and for metal residues from coagulants. The results of this study demonstrate that two different situations have to be considered separately: • In the case of treatment lines composed of separate sedimentation and filtration steps, recycling at the head of the treatment process, even with no treatment, has no significant consequence on the microbial quality of the inlet water, and generates no additional health risk for the consumer. • In the case of treatment lines with no sedimentation step (direct filtration or UF used alone), recycling untreated water generates an excess of risk for the consumer which is not acceptable. Adding a coagulation / sedimentation step in the recycling circuit is sufficient in that case to keep the risk within acceptable limits.

Drinking water infrastructure in the Ashanti Region of Ghana: developing a model for sustainable interventions by non-governmental organizations

2014 ◽  
Vol 5 (1) ◽  
pp. 127-135
Author(s):  
D. Alexander ◽  
N. Wilson ◽  
R. Gieseker ◽  
E. Bartlett ◽  
N. A. Rosseau ◽  
...  
Keyword(s):  
Drinking Water ◽  
Surface Water ◽  
Critical Role ◽  
Clean Water ◽  
Middle Income ◽  
Ashanti Region ◽  
Governmental Organizations ◽  
Non Governmental Organizations ◽  
The University ◽  
The Impact

Access to clean water plays a critical role in advancing health in low- and middle-income countries. Over the past decade, Ghana has met United Nations targets for expanding access to clean water. Non-governmental organizations (NGOs) have taken part in this achievement; however, they have done so with varying success. In 2013, researchers from the University of Chicago, accompanied by local partners, visited seven villages in the Ashanti Region in which a Ghanaian NGO had installed boreholes for drinking water access. Household and leader questionnaires were administered to examine the impact of the project on each community. Four additional villages, which utilize surface water, were visited to establish baseline health and sanitation characteristics. Water samples were collected from primary drinking water sources and tested for coliforms. Two out of seven NGO wells were non-functional and over 35% of respondents cited broken pipes as common problems. Nonetheless, over 60% of respondents reported that a borehole had reduced their water collection time by a median of 30 minutes daily. Coliform counts were lower in samples taken from boreholes relative to samples taken from communities using surface water. Finally, we found redundant water services in many communities and no formalized approach to borehole maintenance.

Summer crops and the impact of pesticides on surface and underground water in the southeast of the province of Buenos Aires, Argentina.

2020 ◽  
Author(s):  
José Luis Costa ◽  
Hernan Angelini ◽  
Eduardo De Geronimo ◽  
Virginia Aparicio
Keyword(s):  
Surface Water ◽  
Management Practices ◽  
Organic Molecules ◽  
Agricultural Land ◽  
Degradation Products ◽  
Environmental Pollutants ◽  
Underground Water ◽  
Environmental Consequences ◽  
Water Courses ◽  
The Impact

<p>Agricultural land is the first pesticide recipient after application. Even if the pesticides are applied in accordance with the regulations, only a smaller amount reaches their objectives (weed or pest), while the rest represents possible environmental pollutants (Hvězdová et al., 2018). In this case, the pesticides they become the non-point source of contamination.</p><p>The objective of this work was to evaluate the impact of summer crop practices on the concentration of pesticides in surface water and groundwater. In soybean and corn crops, next to surface water courses, 2 freatimeters were installed. Groundwater depth was evaluated in six moments (19/12/2018, 4/1/2019, 14/1/2019, 8/2/2019, 15/2/2019 and 25/2/2019). Water samples were extracted and the concentration of 45 organic molecules (pesticides and degradation products) was determined with a UPLC MS / MS. Once the concentration of each molecule was quantified, it was added to establish the proportion corresponding to the total of a) glyphosate + AMPA; b) Atrazine + hydroxy-atrazine + desetyl-atrazine + desisopropyl-atrazine; c) 2,4D and d) other molecules.</p><p>The groundwater was always at a depth greater than 1.30 m in the freatimeters. On average, the proportion of the sum of molecules was: glyphosate metabolite > atrazine metabolite > 2.4D > other organic molecules. The sum of molecules ranged from 0.17 to 39.1 µg l<sup>-1</sup>. On the other hand, the sum of molecules ranged from 1.3 to 12.5 µg l<sup>-1</sup> during the evaluation period. On average, the proportion of the sum of molecules was: glyphosate + metabolite > Atrazine + metabolite > 2.4D  other organic molecules.</p><p>These preliminary results indicate that the grain production system generates an impact evidenced by the presence of synthetic organic molecules in the water. It is important to adjust crop management practices to avoid and / or minimize that impact and its environmental consequences.</p>

Stimulating implementation of best management practices to reduce pesticide loads to surface water in a small agricultural catchment

2020 ◽  
Author(s):  
Piet Seuntjens ◽  
Ellen Pauwelyn ◽  
Els Belmans ◽  
Ingeborg Joris ◽  
Elien Dupon ◽  
...  
Keyword(s):  
Water Quality ◽  
Drinking Water ◽  
Surface Water ◽  
Best Management Practices ◽  
Management Practices ◽  
Point Sources ◽  
Mitigation Measures ◽  
Physical Analysis ◽  
Best Management ◽  
The Impact

<p>High-quality, safe, and sufficient drinking water is essential for life: we use it for drinking, food preparation and cleaning. Agriculture is the biggest source of pesticides and nitrate pollution in European fresh waters. Pesticide occurrences in rivers result from diffuse runoff from farmland or from point sources from the farmyard. Although many best management practices (BMPs) to mitigate these diffuse and point sources are developed and widely disseminated for several years, the effective implementation of mitigation measures in practice remains limited. Therefore, the Waterprotect project has been set up to improve the knowledge and awareness of the impact of crop protection products on the water quality among the many actors, to identify the bottlenecks for implementation of suitable BMPs and further develop new governance strategies to overcome these issues for a more effective drinking water protection. As all actors share the responsibility to deal with the water quality, government agencies (e.g. environmental agencies), private actors (e.g. drinking water company, input supplier, processing industry) and civil society actors (e.g. farmers) are involved in the project. Processes to cope with the problem are initiated in 7 action labs among which the Belgian Bollaertbeek action lab. The study area is a small agricultural catchment where surface water is used as intake to produce drinking water for the nearby city. The area is sensitive to erosion and based on a physical analysis and risk analysis of the catchment, the implementation of filling and cleaning places on individual farms and buffer strips along the watercourse are proposed as suitable measures to tackle the pollution problem. In order to implement them, mechanisms to increase the involvement of targeted farmers and alternative governance systems are studied. Results of the analysis of the water quality issues and the water governance system in the Belgian Bollaertbeek action lab and the strategies to try to improve the uptake of mitigation measures to improve water quality will be presented.</p>

scholarly journals Groundwater–Surface Water Interactions: Recent Advances and Interdisciplinary Challenges

Water ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 296 ◽  
Author(s):  
Jörg Lewandowski ◽  
Karin Meinikmann ◽  
Stefan Krause
Keyword(s):  
Drinking Water ◽  
Surface Water ◽  
Water Resources ◽  
Temporal Dynamics ◽  
Current Knowledge ◽  
Special Issue ◽  
Drinking Water Resources ◽  
Wide Range ◽  
The Impact ◽  
Lack Of Knowledge

The interactions of groundwater with surface waters such as streams, lakes, wetlands, or oceans are relevant for a wide range of reasons—for example, drinking water resources may rely on hydrologic fluxes between groundwater and surface water. However, nutrients and pollutants can also be transported across the interface and experience transformation, enrichment, or retention along the flow paths and cause impacts on the interconnected receptor systems. To maintain drinking water resources and ecosystem health, a mechanistic understanding of the underlying processes controlling the spatial patterns and temporal dynamics of groundwater–surface water interactions is crucial. This Special Issue provides an overview of current research advances and innovative approaches in the broad field of groundwater–surface water interactions. The 20 research articles and 1 communication of this Special Issue cover a wide range of thematic scopes, scales, and experimental and modelling methods across different disciplines (hydrology, aquatic ecology, biogeochemistry, environmental pollution) collaborating in research on groundwater–surface water interactions. The collection of research papers in this Special Issue also allows the identification of current knowledge gaps and reveals the challenges in establishing standardized measurement, observation, and assessment approaches. With regards to its relevance for environmental and water management and protection, the impact of groundwater–surface water interactions is still not fully understood and is often underestimated, which is not only due to a lack of awareness but also a lack of knowledge and experience regarding appropriate measurement and analysis approaches. This lack of knowledge exchange from research into management practice suggests that more efforts are needed to disseminate scientific results and methods to practitioners and policy makers.

scholarly journals Distributions of Microplastics in Surface Water, Fish, and Sediment in the Vicinity of a Sewage Treatment Plant

Water ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 3333
Author(s):  
Tae-Jin Park ◽  
Seung-Hyun Lee ◽  
Myung-Sung Lee ◽  
Jae-Kwan Lee ◽  
Ji-Hyoung Park ◽  
...  
Keyword(s):  
Surface Water ◽  
Rainy Season ◽  
Wastewater Treatment Plants ◽  
Sewage Treatment ◽  
Sewage Treatment Plant ◽  
Treatment Plant ◽  
Dry Season ◽  
Water Fish ◽  
Receiving Waters ◽  
The Impact

Microplastics are ubiquitously found in freshwater and marine environments worldwide. In particular, wastewater treatment plants (WWTPs) or sewage treatment plants (STPs) have been recognized as a main source of microplastics in the receiving freshwater. However, only a few studies have been conducted to examine the impact of these facilities on receiving waters. In this study, we investigated the distribution of microplastics in surface water, fish, and sediment near a sewage treatment plant (STP) in the Tanchon stream, one of the main tributaries flowing into the Han River, Korea. The concentration of microplastics in water varied spatially and temporarily, ranging between 5.3 and 87.3 particles/m3 (31.4 ± 28.5 particles/m3). In fish, the concentration in upstream and downstream sites was 7.3 ± 7.3 and 12.4 ± 17.9 particles/fish, respectively. Spatially, the downstream site was the most polluted with microplastics in water and fish. The concentration of microplastics was positively correlated with fish body length and weight. In sediment, microplastic concentration in upstream and downstream sites was 493.1 ± 136.0 and 380.0 ± 144.2 particles/kg, respectively. The contribution of upstream to the microplastic load in downstream was 15.8% in dry season (April), which was higher than that of STP effluent and Yangjaechon creek. Meanwhile, the highest load was observed in STP effluent (5.1%) in rainy season (August). Microplastics were more abundant in water in the rainy season (37.4 ± 37.0 particles/m3) than in the dry season (28.2 ± 22.2 particles/m3). Polyethylene (49%) and polypropylene (18%) were the most abundant polymer types in water, fish, and sediment. Regarding shape of microplastics, fragments were dominant (95%) over fiber and film in water, fish, and sediment.

scholarly journals Assessing protozoan risks for surface drinking water supplies in Nova Scotia, Canada

2015 ◽  
Vol 14 (1) ◽  
pp. 155-166 ◽  
Author(s):  
Wendy Krkosek ◽  
Victoria Reed ◽  
Graham A. Gagnon
Keyword(s):  
Drinking Water ◽  
Nova Scotia ◽  
Surface Water ◽  
Quality Analysis ◽  
Water Supplies ◽  
Log Reduction ◽  
Disability Adjusted Life ◽  
Life Years ◽  
Cryptosporidium Oocysts ◽  
Giardia Cysts

Protozoa, such as Cryptosporidium parvum and Giardia lamblia, pose a human health risk when present in drinking water. To minimize health risks, the Nova Scotia Treatment Standards for surface water and groundwater under the direct influence of surface water require a 3-log reduction for Giardia cysts and Cryptosporidium oocysts. This study determined the protozoan risk of municipal surface source waters in Nova Scotia, through the use of a pre-screening risk analysis of water supplies, followed by subsequent water quality analysis of the seven highest risk supplies. The water supplies were monitored monthly for 1 year to obtain baseline data that could be used for a quantitative microbial risk assessment (QMRA). The QMRA model outcomes were compared to the Health Canada health target of 10−6 disability-adjusted life years/person/year. QMRA modeling shows that the treatment facilities meet the required log reductions and disability-adjusted life year target standards under current conditions. Furthermore, based on the results of this work, Nova Scotia should maintain the current 3-log reduction standard for Giardia cysts and Cryptosporidium oocysts. The results of this study show that a pre-screening step can help to inform water sources that are particularly vulnerable to protozoan contamination, which can lead to more focused, cost-effective sampling, and monitoring programs.

Comparison of three methods to concentrate Giardia cysts and Cryptosporidium oocysts from surface and drinking waters

2010 ◽  
Vol 62 (1) ◽  
pp. 196-201 ◽  
Author(s):  
Helmi Karim ◽  
Skraber Sylvain ◽  
Leblanc Laurence ◽  
Hoffmann Lucien ◽  
Cauchie Henry-Michel
Keyword(s):  
Drinking Water ◽  
Surface Water ◽  
Water Type ◽  
Standard Protocol ◽  
Recovery Rates ◽  
Drinking Waters ◽  
Cryptosporidium Oocysts ◽  
Giardia Cysts

In this study, three methods commercialized by Pall (Envirochek HV), Idexx (FiltaMax) and Whatman (Cryptest) to concentrate Giardia cysts and Cryptosporidium oocysts from surface and drinking waters were compared according to the EPA standard protocol. Twenty litres of surface and 100 litres of drinking waters were inoculated with 103 (oo)cysts before being concentrated by filtration. Our results show that recovery rates of Giardia cysts from surface water was significantly higher using FiltaMax (91 ± 12%) than Cryptest (57 ± 9%) or Envirochek HV (60 ± 4%) while recovery from drinking water was equivalent using FiltaMax (84 ± 7%) or Cryptest (78 ± 7%) but lower using Envirochek HV (34 ± 29%). Recovery of Cryptosporidium oocysts from surface water was significantly higher using Envirochek HV (65 ± 5%) than using FiltaMax (45 ± 7%) or Cryptest (50 ± 7%) while recovery rates from drinking water was equivalent using either FiltaMax (48 ± 8%), Cryptest (57 ± 4%) or Envirochek HV (64 ± 22%). Finally, regardless of the water type, all methods tested allowed recovery rates superior to 24% complying with the EPA standard protocol. Timing, material and practicability associated with each method are discussed.

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