Total Coliform Concentrations Research Articles

Occurrence and concentrations of traditional and emerging contaminants in onsite wastewater systems and water supply wells in eastern North Carolina, USA.

Onsite wastewater treatment systems (OWTSs) and private wells are commonly used in Eastern North Carolina, USA. Water from private wells is not required to be tested after the initial startup, and thus persons using these wells may experience negative health outcomes if their water is contaminated with waste-related pollutants including bacteria, nitrate or synthetic chemicals such as hexafluoropropylne oxide dimer acid and its ammonium salt (GenX). Water samples from 18 sites with OWTSs and groundwater wells were collected for nitrate, Escherichia coli (E. coli), total coliform, and GenX concentration analyses. Results showed that none of the 18 water supplies were positive for E. coli, nitrate concentrations were all below the maximum contaminant level of 10 mg L-1, and one well had 1 MPN 100 mL-1 of total coliform. However, GenX was detected in wastewater collected from all 18 septic tanks and 22% of the water supplies tested had concentrations that exceeded the health advisory levels for GenX. Water supplies with low concentrations of traditionally tested for pollutants (nitrate, E. coli) may still pose health risks due to elevated concentrations of emerging contaminants like GenX and thus more comprehensive and routine water testing is suggested for this and similar persistent compounds.

Logistic Model for Predicting Coliform Growth in Wastewater Effluent From the Chambo River (Ecuador)

Purpose: The objective of this work is to apply a predictive model of bacterial growth to determine the concentration of total coliforms, under controlled laboratory conditions, in wastewater from the city of Riobamba that flows into the Chambo River (Ecuador).   Theoretical Framework: Wastewater pollution is a global problem that affects water quality and public health. Population growth has a drastic impact on the contamination of water bodies, particularly in Ecuador, since most of the effluents are not adequately treated, which becomes a public health and environmental problem. For this reason, over the years, total and fecal coliforms have been used as indicators of water quality.   Design/Methodology/Approach: The study used a mathematical modeling approach of a logistic and deterministic type, and calculated through an executable command designed in the integrated development environment (IDE) with the Visual C# programming language (logic) and the XAML design language (interface).   Findings: The results achieved are 1) the theoretical construction of a mathematical model (logistic model) starting from a differential equation and the taking of three experimental measurements, 2) the computer construction of the bacterial growth model and 3) it has been demonstrated that there is agreement between the values obtained from the model of total coliform growth and the experimental results with a margin of error of less than 1%.   Research, Practical & Social Implications: This information can be used by stakeholders to determine actions that could improve current conditions.   Originality/Value: The result of this study emphasizes that the model proposed can reproduce the growth of coliforms up to a maximum growth point, it is necessary to continue with the development of the same in the stationary phase of bacterial growth and then in the decay phase.

Logistic Model for Predicting Coliform Growth in Wastewater Effluent From the Chambo River (Ecuador)

Purpose: The objective of this work is to apply a predictive model of bacterial growth to determine the concentration of total coliforms, under controlled laboratory conditions, in wastewater from the city of Riobamba that flows into the Chambo River (Ecuador).   Theoretical Framework: Wastewater pollution is a global problem that affects water quality and public health. Population growth has a drastic impact on the contamination of water bodies, particularly in Ecuador, since most of the effluents are not adequately treated, which becomes a public health and environmental problem. For this reason, over the years, total and fecal coliforms have been used as indicators of water quality.   Design/Methodology/Approach: The study used a mathematical modeling approach of a logistic and deterministic type, and calculated through an executable command designed in the integrated development environment (IDE) with the Visual C# programming language (logic) and the XAML design language (interface).   Findings: The results achieved are 1) the theoretical construction of a mathematical model (logistic model) starting from a differential equation and the taking of three experimental measurements, 2) the computer construction of the bacterial growth model and 3) it has been demonstrated that there is agreement between the values obtained from the model of total coliform growth and the experimental results with a margin of error of less than 1%.   Research, Practical & Social Implications: This information can be used by stakeholders to determine actions that could improve current conditions.   Originality/Value: The result of this study emphasizes that the model proposed can reproduce the growth of coliforms up to a maximum growth point, it is necessary to continue with the development of the same in the stationary phase of bacterial growth and then in the decay phase.

Effect of dissolved ozone flotation thickening process on coliform bacteria and antibiotics simultaneous abatement: A pilot-scale study

This study focused on the removal of the total coliforms, fecal coliforms and four target antibiotics in the dissolved ozone flotation (DOF) thickening sludge process. Additionally, the thickened effluent chromaticity and its effect on thickened sludge hydrolysis process were investigated. Ozonation in the DOF process could inactivate coliforms by oxidizing cellular components and destroying genetic material, as well as altering the chemical structure of antibiotics, leading to the degradation of antibiotics. At an O3 dosage of 16 mg/g TS, the concentration of total coliforms and fecal coliforms decreased by 2.2 log and 2.4 log, corresponding to an overall removal rate of 99.4 % and 99.7 %, respectively. The total degradation rate of four target antibiotics (tetracycline (TC), oxytetracycline (OTC), norfloxacin (NOR), ofloxacin (OFL)) were 66.5 %, 68.8 %, 53.3 % and 57.5 %, respectively. The chromaticity removal rate of the thickened effluent reached 95 %. Analysis of fluorescence spectra indicated alterations in the fluorescence properties of dissolved organic matter, resulting in a decrease in fluorescence intensity by ozonation. The thickened sludge had higher hydrolysis rates, resulting in a greater production of volatile fatty acids (VFAs). This was mainly attributed to the increased amount of soluble protein and carbohydrate in the substrate after DOF treatment, which was more conducive for the rapid conversion of hydrolysis into VFAs during the initial stage. These results provided new ideas for upgrading and transforming the thickening process of wastewater treatment plants (WWTPs).

Effectiveness of communal wastewater treatment plant in peri-urban Yogyakarta, Indonesia, for Escherichia coli removal

Yogyakarta Special Region, one of Indonesia’s provinces, has many communal wastewater treatment plants (CWWTPs). However, less than 40% of the province’s CWWTPs are operationally viable. Based on data from the Environmental Agency of Sleman Regency, the physical and chemical parameters of approximately 163 CWWTPs were evaluated. Their biological characteristics, however, still need to be understood. This study aimed to investigate the efficacy of CWWTPs in terms of biological parameters, specifically total Coliform and Escherichia coli (E. coli) concentrations in the observed CWWTPs. Five CWWTPs were used as study sites, namely IPAL Manunggal Pringgodani Sejati, IPAL Bakti Warga, IPAL Tambakrejo Bersih, IPAL Nologaten Bersih, and IPAL Andum Roso, which were classified as extremely high and high sanitation risk areas. The total Coliform and E. coli concentrations were determined using MPN techniques based on APHA 9221 (2017). The study found that the E. coli removal effectiveness of the CWWTPs in the very-high sanitation risk areas, namely IPAL Manunggal Pringgodani Sejati, IPAL Bakti Warga, and IPAL Tambakrejo Bersih, was 49%, 18%, and 83%, respectively. Furthermore, in high sanitation risk regions, such as IPAL Nologaten Bersih and IPAL Andum Roso, the CWWTPS were 17% and 73%, respectively. Total Coliform concentrations at all CWWTPs were below the standard limit set by Permen LHK No 68 and the EPA. The findings of this study will help to improve understanding of the WWTP process for E. coli elimination, which will, in turn, help to improve CWWTP performance.

Faucet-mounted point-of-use drinking water filters to improve water quality in households served by private wells

Approximately 13 % of Americans rely on private wells for household potable water. As private wells are not regulated beyond initial construction and often employ limited or no treatment, source water from wells can be vulnerable to contamination. While several studies have assessed applications of point-of-use (POU) filters in improving municipal tap water quality, few have investigated their use with private well water. This effort aims to build on previous examinations of POU treatment as a strategy to reduce adverse household drinking water exposures by: 1) assessing the effectiveness of commercially available faucet-mounted POU filters for improving microbial and chemical water quality in homes with private wells; and 2) documenting household ease of use and satisfaction with the filters. Faucet-mounted POU filters were distributed to 21 homes reliant on private wells in southern West Virginia and southwestern Virginia. Study participants were asked to collect water samples from two taps in their homes pre-filter installation, and again two-weeks and four-weeks post-installation. Participants filled out surveys about perceptions of their drinking water and the filter. Concentrations of Total Coliform, Ba, Cd, Cr, U, Cu, Pb, Al, Fe, Mn, Zn, and Sr were significantly lower (p < 0.05, Wilcoxon Rank Sum) in filtered water samples compared to paired unfiltered samples (n = 42) for the study period. However, concentrations of certain contaminants in filtered samples from homes with high levels of source water contamination still exceeded drinking water standards. Less than half of study participants reported that they intended to keep using the filters, citing issues of flowrate. Our findings suggest that faucet-mounted POU filters, while effective in reducing contaminants, might not be an appropriate intervention to improve water quality for all homes on private well water. Future investigation is required to improve filter user satisfaction and better assess appropriate source water chemistries for implementation.

Removal of Pathogenic Bacteria in a Horizontally Fed Subsurface Constructed Wetland Hybrid System

The management of effluents and their treatment is a fundamental issue in water management, the removal of different types of contaminants is another relevant issue for public health and the environment. Bacteria are one of the main types of contaminants in untreated water discharged to receiving bodies. The objective of this research was to evaluate the removal efficiency of pathogenic bacteria in a horizontal feeding subsurface artificial wetland that treats wastewater originated from the Boca de Río Technological Institute, Veracruz, Mexico. A hybrid system composed of seven cells with three types of substrates and ornamental type vegetation was designed; the indicators evaluated were the concentration of total and fecal coliforms and the efficiency of bacterial removal in the stages of the system. The artificial wetland system demonstrated a significant reduction (p &lt; 0.05) between the different cells of the system. The values of pathogenic bacteria removal obtained in the wetland were higher than 99% in the cells of the system and times. In conclusion, it was identified that the interaction of the components of this system and its operation under the climatic seasons of the site influenced the removal efficiency of pathogenic bacteria, allowing optimal removal efficiency.

Assessment of solid and liquid wastes management and health impacts along the failed sewerage systems in capital cities of African countries: case of Abidjan, Côte d'Ivoire

The management of domestic wastewater and rainwater is a major concern for the population of Yopougon. The study presents the causes of wastewater discharge from dysfunctional sewers and their health impacts on the population. It also highlights the environmental and health risk associated with poor solid and liquid waste management. This was based on literature search, semi-participatory workshop, physicochemical and bacteriological characterization of wastewater and finally through a household survey. The field survey was conducted on 245 household heads obtained using the Canadian statistical guidelines. The results obtained indicated that all main pollution indicators were; total nitrogen (TN, 525 ± 0.02 to 3077 ± 0.3 mg/l), nitrates (NO3, 146 ± 0.01 to 1347 ± 0.12 mg/l), biochemical oxygen demand (BOD, 278 ± 195.16 to 645 ± 391.74 mg/l), chemical oxygen demand (COD, 940 ± 650.54 to 4050.5 ± 71.42 mg/l) and total dissolved solids (TDS, 151 ± 9.9 to 766 ± 237.59 mg/l) which were above the values recommended by the World Health Organization (WHO) and Cote d'Ivoire national policy guidelines standards for the discharge of effluents into the environment. The analysis of the bacterial flora of the effluents revealed that the concentrations of Total Coliforms and fecal streptococci exceeded the values recommended by the WHO and national policy guidelines standards. This means that the populations of this area are prone to infectious diseases. Diseases such as malaria (84.53%), respiratory infections (61%), diarrhea (48.66%), intestinal diseases (44.5%), and typhoid fever (28.84%) were prevalent in the surveyed households.

Growth Performance of Mytilus galloprovincialis Lamarck, 1819 under an Innovative Integrated Multi-Trophic Aquaculture System (IMTA) in the Mar Grande of Taranto (Mediterranean Sea, Italy)

The cultivation of the Mediterranean mussel, Mytilus galloprovincialis Lamarck, 1819, has been tested in an innovative Integrated Multitrophic Aquaculture system (IMTA) in the Mar Grande of Taranto, as part of the EU-funded Remedialife project. This farming method could solve several problems including the low growth rate in mesotrophic environments while reducing the environmental impact of fish mariculture. Three productive cycles have been carried out. The first (2018–2019, traditional experiment) was conducted in three long lines around six cages of the fish farm in order to evaluate total mussel production under the innovative IMTA system and quality for human consumption by analyzing the concentration of culturable heterotrophic bacteria, total and fecal coliforms, Escherichia coli and Salmonella spp. in mussel tissues. In addition, 17 polycyclic aromatic hydrocarbons (PAHs), including 16 EPA priority compounds and seven polychlorinated biphenyls (PCBs), which are indicators of PCB contamination in the environment, were analyzed using gas chromatography in conjunction with a mass spectrometer. The second cycle (2020–2021, horizontal distance experiment) aimed to test the influence of fish cages on mussel growth by placing mussels near and far from the fish cages. The third cycle (2021–2022, vertical distance experiment) aimed to overcome the phenomenon of “heat waves” that can occur in the Mar Grande of Taranto during summer by testing the growth performance of mussels at two different depths (1 and 12 m). The following parameters were measured: Shell Length, L (mm); Shell Dry Weight, SDW (g); Flesh Dry Weight, FDW (g); Condition Index, IC = FDW/SDW. The results showed that the best growth performance was obtained near the fish cages and at a depth of 12 m. Moreover, the indicators of microbial contamination and concentrations of chemical compounds analyzed in mussel tissues cultured under the innovative IMTA system were in compliance with the reference values of European regulations.

Hydrogeochemical characteristics of Kodku River of Lalitpur District, Nepal

Abstract Hydro-geochemical characteristics of Kodku River of Lalitpur, Nepal were determined through analysis of physicochemical parameters including major anions and cations. This study also characterizes and evaluates the suitability for drinking and irrigation. The results showed that river water is slightly alkaline toward the downstream. The concentration of BOD, COD, and total coliform was much higher than its prescribed limits for drinking purposes in downstream, whereas a few samples in upstream are fit for drinking with reference to WQI value. The estimated sodium percentage (Na%), sodium adsorption ratio (SAR), permeability index (PI), magnesium adsorption ratio (MAR), and Kelly's ratio (KR) depict the excellent and safe categories for irrigation purposes. The obtained Wilcox diagram also revealed that river water falls under the C1S1 category which is safe for crops. Hydrogeochemical facies in Piper diagrams signifies the dominance of Ca–HCO3 type. Similarly, Gibbs maps indicate mineral (rock) weathering, whereas mixing diagram reveals carbonate weathering as the main controlling factor of major ion species. This study provides information on the hydrogeochemical properties of the river and its suitability for drinking and irrigation. Despite the comprehensiveness, the study can be an effective approach for countries with similar levels of water resources management.

Analysis of River Water Quality Based on Pollution Index Water Quality Status, Lombok District, NTB

Leneng River is one of the rivers in Praya City, Central Lombok Regency, which receives domestic, agricultural, and household industrial waste. Various community activities along the banks of the Leneng River have affected river water quality. Some communities on the banks of the Leneng River, from upstream to downstream, still use river water for their daily needs. This study aims to 1) analyze the water quality of the Leneng River in terms of environmental parameters (Physical, chemical, and biological) and 2) Determine the level of pollution of the Leneng River water using the Pollution Index (IP) method. River water quality measurements were carried out at 3 (three) sample points. Parameters measured and observed were physical parameters, namely Total Solid Suspend (TSS); chemical parameters, namely pH, Total Phosphate (T.PO4), Biological Oxygen Demand (BOD), Chemical Oxygen Demand (COD), Dissolved Oxygen (DO), and biological parameters namely Total coliform and Fecal Coliform. This type of research is survey research with a quantitative descriptive approach. The results showed that the TSS value at sample point 1 (upstream) exceeded the required quality standard; the highest TSS concentration value was 54 mg/L, and the lowest at sample point 2 (middle section) was 2.50 mg/L. Value parameter concentration pH 7.7-8.7, T.PO4 value 0.05 mg/L-0.29 mg/L, BOD value 0.17-0.42 mg/L, COD concentration value 8 mg/L -9mg/L, and DO value of 6.07 mg/L-7.57 mg/L, this shows that the concentration for chemical parameters still meets the class I water quality standards according to PP 22 of 2021, while the total coliform parameter value and Facel coliform have exceeded class I water quality standards. The total coliform concentration value is 10,000 - 20,000 MPN/100 mL, and the Fecal coliform value is 600 MPN/100 mL – 2,500 MPN/100 mL, while based on the Pollution Index (IP) quality status water in the upstream with a value of 2.84, the middle part of 1.97, and the downstream part of 2.84, this shows a decrease in water quality from upstream to downstream of the river, with a level of pollution in the lightly polluted category.

Effectiveness of the tropical plants Rhynchospora corymbosa and Coix lacryma-jobi in vertical flow constructed wetlands for municipal primary sewage effluent treatment

The performance of two tropical plants, Rhynchospora corymbosa L. (RC) and Coix lacryma-jobi, L (CL) in treatment of primary sewage effluent in lab-scale vertical-flow constructed wetlands (VFCW) along with no plant control wetland was investigated. A batch-flow VFCWs were operated under batch fill and drain hydraulic loading system with hydraulic retention times (HRT) of 0.5, 1, and 2 days and fill rate of 8 L/day. Removal of solids, organics, nutrients, and pathogens were monitored. The volumetric contaminant removal rates were best described by 1st order kinetics except for ammonia and phosphate, which was best described by Stover-Kincannon kinetics. Influent TSS, PO4 3−, COD, BOD5, and total coliform concentration were low but high in NH4 + concentration. CL was better in nutrient removal as HRT increases compared to RC. RC was more efficient at TSS, turbidity, and organics removal. Pathogen removal was independent of plant type but HRT. Solids and organic removal were lower in CL planted CWs due to preferential flow paths created by their bulky root. CL planted CWs removed more nutrients followed by RC planted CWs and then no-plant control CWs. The results of these tests demonstrate that both CL and RC are suitable for the treatment of municipal wastewater in VFCW system.

Study on Bacteriological Measurement of Clean Water in Raja Ampat

The availability of clean water is a right that must be obtained by all humans. Unfortunately, some water sources in Indonesia are polluted by total coliform and Escherichia coli and threaten health. This study aims to measure total coliform and Escherichia coli in the Weisai sub-district, Raja Ampat Regency, West Papua province as an effort to monitor environmental quality. This research is an observational study with a quantitative approach. Primary data in this study is the measurement of total coliform and Escherichia coli. The samples used were clean water in the borehole well of Bambang Sutejo village (T1); the dug well of Nyonya Fransina village (T2); and the dug well of Om Miter village (T3). Sample testing was conducted by the Environmental Health and Disease Control Technical Center (BTKLPP), Ambon City, and taken on November 28, 2022. The test results obtained, total coliform parameters of 1,600 MPN/100 mL and Escherichia coli 2.2 at T1. Meanwhile, the T3 concentration of total coliform and Escherichia coli exceeded 1,600 MPN/100 mL. T1 and T3 have values that exceed quality standards. This is due to livestock waste that does not have a wastewater disposal channel and the absence of communal domestic wastewater disposal channels

Impact of usership on bacterial contamination of public latrine surfaces in Kathmandu, Nepal

According to the United Nations (UN) Sustainable Development Goals (SDGs), community or public toilets shared by more than one household are not considered “safely managed” under SDG 6.2. However, many populations around the globe, particularly in urban settings, lack access to private sanitation facilities. For this reason, there is a need to evaluate the cleanliness of community or public toilets in these settings and examine best practices for maintaining them. This study had three aims: 1) build on previous data collected in March 2018 at public latrines to determine whether cleaning protocols were sustained, 2) examine relationships between latrine cleanliness and usership, and 3) identify latrine surfaces with higher concentrations of bacterial contamination. In March 2018 and December 2019, swab samples were collected from public latrine surfaces in Kathmandu, Nepal. Sampling occurred in “clean” conditions–after cleaning and before the latrine was opened for use–and “dirty” conditions–during operating hours. Samples were analyzed for concentrations of total coliforms (TC) and Escherichia coli (EC). The number of latrine users prior to the “dirty” sample collection was recorded (in December 2019 only). Results found that both TC and EC concentrations were significantly lower during “clean” rather than “dirty” conditions and both TC and EC concentrations increased with the number of users over time. TC and EC concentrations differed by surface type during dirty and clean conditions (p&lt;0.05). Findings suggest cleaning protocols established at this public toilet site were adequately maintained two years later.

Tidal effect on the dispersion of fecal pollution indicator bacteria and associated health risks along the Kribi beaches (Southern Atlantic coast, Cameroon)

Assessment of fecal contamination indicator bacteria concentrations on beaches are important for health risk prevention and management. This study assessed temporal changes in bacterial abundances as a function of tidal cycles and seasons along the Kribi beaches, Cameroon. Overall, samples taken during low and high tides during the different seasons of the year showed that the waters of Kribi beaches are exposed to fecal contamination due to the presence of different concentrations of fecal coliforms (5–35 CFU/100 ml), total coliforms (100–600 CFU/100 ml), Escherichia coli (0–15 CFU/100 ml), Streptococcus feacalis (50–700 CFU/100 ml), Pseudomonas aeruginosa (300–7200 CFU/100 ml), Vibrio cholerea (5–250 CFU/100 ml), Vibrio parahemoliticus (0–115 CFU/100 ml), and Aerobic Mesophilic Heterotrophic Bacteria (99–875 CFU/100 ml). Regardless of bacterial strain and sampling site, cell abundances were significant at low tides and during rainy seasons. At each sampling station (Mpalla, Ngoyè and Mboamanga), depending on the seasons and tidal cycles, significant correlations were recorded between the abundances of some bacterial strains and some environmental variables (P< 0.05). The presence and high abundance of these potentially pathogenic bacterial strains in the waters of Kribi beaches constitute a real public health threat for swimmers. The limitation of this microbiological pollution requires the implementation of an efficient collection and treatment plan for solid and liquid waste (sanitary wastewater) in the city of Kribi.

Meteorological and Water Quality Factors Associated with Microbial Diversity in Coastal Water from Intensified Oyster Production Areas of Thailand

Coastal pollution is of public health concern due to the possibility of bacterial contamination in aquaculture affecting health risk and seafood safety. This study determined the concentrations of total coliforms, fecal coliforms, E. coli, and V. parahaemolyticus and the presence of V. cholerae and Salmonella in water and measured water quality and meteorological factors from the major oyster cultivation areas in Thailand. The water samples (n = 363) were collected from Surat Thani (n = 60), Chanthaburi (n = 60), Trat (n = 60), Phetchaburi (n = 60), Chonburi (n = 63), and Phang Nga (n = 60) from February 2021 to January 2022. The prevalence of total coliforms (96.7%), fecal coliforms (60.6%), E. coli (22.9%), along with the prevalence of Salmonella (2.5%), Vibrio parahaemolyticus (74.9%), and V. cholerae (11.3%) were determined. Common Salmonella serovars were Othmarschen and Lamberhurst. The concentration of E. coli was significantly associated with dissolved oxygen and precipitation (p &lt; 0.0001). Therefore, continuing microbiological monitoring and surveillance of water for coastal aquaculture is important to produce safe aquatic products. Furthermore, raising awareness of coastal pollution and seafood safety will help enhance sustainable coastal fisheries in Thailand.

Removal of pathogens from greywater using green roofs combined with chlorination

Greywater is an important alternative water resource which could be treated and reused in buildings, reducing the freshwater demand in drought affected areas. For the successful implementation of this solution, it is important to ensure the microbial safety of treated greywater. This study examined the microbiological quality of treated greywater produced by an emergent nature-based technology (green roofs) and a chlorination process. Specifically, the effect of substrate, substrate depth, and vegetation on the removal of total coliforms, Escherichia coli, and enterococci in experimental green roofs treating greywater was examined for a period of about 12 months. In addition, the ability of chlorination to inactivate the abovementioned pathogen indicators was evaluated and their potential regrowth was examined. Results shown that green roofs filled with 10 cm of perlite reduce total coliform concentration by about 0.4 log units while green roofs filled with 20 cm of vermiculite reduce total coliform concentration by about 1.2 log units. In addition, the use of vegetation in green roofs improves the removal of pathogenic bacteria by about 0.5 log units in comparison with unvegetated systems. In all cases, the effluents of green roofs failed to satisfy the criteria for indoor reuse of treated greywater for non-potable uses such as toilet flushing without a disinfection process. The addition of 3 mg/L of chlorine in the effluent provided safe greywater microbiological quality for storage periods of less than 24 h, while longer periods resulted in the significant regrowth of pathogens. In contrast, a chlorination dose of 7 mg/L completely secured inactivation of pathogen indicators for periods of up to 3 days.

Analysis of Residual Chlorine and Total Coliform on Consumers of Perumdam Maja Tirta, Mojokerto City

This study aims to determine the concentration of residual chlorine and net total Coliform distributed by Perumdam Maja Tirta Water Supply Company and received by consumers. Water samples were taken from 7 locations on the distribution network a residential area of Perumdam Maja Tirta, the first sample taken at the reservoir of the Water Treatment Plant of Perumdam Maja Tirta and six samples from consumers. The residual chlorine concentration data and Total Coliform were mapped using Surfer 16 Software, producing an iso concentration map in the form of contour lines. The results showed that the concentration of residual water chlorine received by consumers of Perumdam Maja Tirta Mojokerto City ranged from &lt;LoQ 0.1 mg/L to 0.3 mg/L. The further away from the IPA, the concentration of residual water chlorine decreased. Total Coliform parameters ranged from &lt;1.8 – 240/100 ml in water received by consumers of Perumdam Maja Tirta Mojokerto City. There is a need to improve the quality of water services to consumers regarding water treatment and distribution.

Determining water quality of the lower basin of the Usumacinta River in Tabasco, Mexico

Objective: The objective of this study was to determine the water quality of the lower basin of the Usumacinta River, based on its physicochemical and microbiological characteristics. Design/methodology/approach: There were taken 11 monthly samplings of surface water during the rainy season, from June to December, 2017 and in the dry season, from April to May, 2018, in three different sites. The parameters of temperature, pH, Electrical Conductivity (EC), Total Dissolved Solids (TDS), Total Suspended Solids (TSS), total phosphorus (TP) and Nitrogen nitrate (N-nitrate) were evaluated. Significant statistical differences (p≤0.05) between seasons and between sites were determined. Results: The results obtained were compared with Mexican regulations and Ecological Criteria for water quality. The parameters such as EC, TDS, TSS and total phosphorus showed substantial differences among seasons. The temperature, pH, EC and N-nitrate, did not exceed the maximum permissible limits for the use of irrigation water, urban public use and protection of aquatic life. However, the presence of E. coli and total coliforms from 530 to&gt; 24 196 MPN/100 ml was recorded throughout the study period. Findings/conclusions: Parameters under study did not show significant differences between sites. The rainy season had an important effect on the increase in concentrations of TSS, TP, N-nitrate and total coliforms. Also, that maximum concentrations were recorded during the study period in the sampling sites of Boca del Cerro (R1) and Puente Chablé (R2).

Bacteriological Contamination of Groundwater Affected by Septic Tanks Condition in Koto Tangah District, Padang, Indonesia

Introduction: Padang City Sanitation Working Group reported that 34.32% of households in Padang City use unsafe latrines with septic tanks that still do not meet the standards which potentially causes the wastewater from the septic tanks to contaminate the water of the wells. This study was conducted to analyse the effects of the septic tank condition on the microbiological quality parameters of the well-water, namely total coliform and Escherichia coli in Koto Tengah District, Padang. Methods: This study uses a quantitative research method. The data were collected by questionnaires, observation, interviews, and laboratory tests. Water sampling was collected by using the purposive sampling method where the water is taken from 20 wells originating from 10 coastal and 10 non-coastal areas. Results and Discussion: Total coliform was found in all samples, while Escherichia coli was found in two samples from coastal and five from non-coastal regions. The septic tank condition had a strong correlation with the total coliform concentration (r= -0.531) and affected the total coliform concentration in the well-water by 30.8%. However, the Escherichia coli concentration was not related and not affected by the condition of the septic tank (p&gt;0.05). There was no significant difference in the concentration of the microbiological parameters in the coastal and non-coastal areas. Conclusion: The microbiological quality of the well-water did not comply with the quality standards to be used as water sources for the community. The total coliform concentration in the well-water was shown to have a close relationship with the septic tank's condition.