Body Contact Recreation Research Articles

Spatiotemporal Variability Comparisons of Water Quality and Escherichia coli in an Oklahoma Stream

AbstractFecal indicator bacteria, Escherichia coli, for primary body contact recreation (PBCR) in Oklahoma waterbodies, is defined as the geometric mean of 10 samples from the recreation season, May 1 to September 30, with an impairment threshold of 126 colony forming units (cfu) per 100 mL. However, the water quality standards provide limited guidance on spatiotemporal and environmental factors that could influence samples collected and analyzed. In this study, two stream cross sections under baseflow conditions in a central Oklahoma urban perennial stream, Spring Creek, were densely sampled to investigate temporal and spatial variability of E. coli concentrations and water quality parameters across the stream channel. Water quality parameters (specific conductivity, temperature, dissolved oxygen, pH, turbidity, and total suspended solids (TSS)), stream discharge, and bacteria samples were collected simultaneously at equal intervals across the two cross sections in the morning and afternoon during one summer day with sunny, dry, and hot weather conditions. Results indicate a significant difference between time‐of‐day samples and water quality parameters and E. coli concentrations. Strong correlations between temperature, dissolved oxygen, and time versus E. coli concentrations were observed, while location, turbidity, and TSS were not significant or correlated to measured values. Furthermore, E. coli concentrations were highly variable spatially across each stream cross section, regardless of time of day or location. Results from this study provide an initial indication that stream water quality, spatial cross section sample location, and diurnal variations may be influencing factors on bacteria concentrations.

Impact of Different Land Uses on the Escherichia coli Concentrations, Physical and Chemical Water Quality Parameters in a Tropical Stream

Rural streams are important source of water for the nearby communities. However, bacterial contamination from agriculture and human settlement may render the water unsuitable for drinking and body contact recreation. Hence, the objective of this study was to determine the impact of different land uses such as animal farming and human settlement on E. coli concentrations in the Serin River, a tropical stream. Samplings were conducted at 9 stations from September 2009 to March 2010. Results showed that E. coli concentrations ranged from 2,000-6,900,000 CFU/100 mL with E. coli concentrations in fish aquaculture water exceeding the WHO standard. Animal and crop farming stations showed the highest E. coli concentrations in the tributaries. Re-suspension from stream sediment and non-point sources such as runoff contributed to the high concentrations observed in the main river. Multiple linear regressions indicated that total suspended solids and dissolved oxygen were significant water quality parameters and they explained 68.1% of the total E. coli variations observed.

Development of a Water Quality Model to Support a Pathogen TMDL (Newport Bay, California, USA)

Newport Bay (Orange County, California) is listed by the California State Water Resources Control Board (SWRCB) as a water quality limited receiving water body because of sporadic exceedances of the fecal coliform water quality objectives for body contact recreation. Consistent with federal and state requirements, a Total Maximum Daily Load (TMDL) is being implemented in the watershed. The fecal coliform TMDL in Newport Bay is a phased approach for understanding and controlling the microbiological water quality in the to ensure the reasonable protection of the Bay's beneficial uses. An important initial step within that TMDL was to assess the impairment of the body contact recreation beneficial use (REC-1) of Newport Bay receiving waters through characterizing the risk of illness associated with REC-1 exposure. A health risk assessment investigation was developed to characterize that risk. The health risk assessment investigation involved the integration of a population based model of disease transmission, a water quality modeling component necessary for estimating pathogen dose as part of the exposure assessment, and site-specific population use and receiving water data collection. The Water Environment Research Foundation funded the water quality modeling component of the health risk assessment investigation, which is the focus of this report. Also provided within this report is an overview of the health risk assessment methodology, a summary of the major findings from the risk assessment investigation, and a discussion of how the health risk methodology may be applied to other watersheds where impairment of the REC-1 beneficial use is in question. The major findings of the health risk assessment investigation indicated that (1) the risk of illness from REC-1 use in Newport Bay, estimated using two separate methods was generally below levels considered tolerable by US EPA, and (2) the reduction of controllable sources of pollution would not appreciably reduce the existing risk. Based on the collection of site-specific exposure data and the health risk characterization, it was determined that evaluating the impairment of the REC-1 beneficial use requires a more rigorous and comprehensive health based approach than that prescribed by the current regulations for recreational waters. This title belongs to WERF Research Report Series ISBN: 9781843396642 (Print) ISBN: 9781780403137 (eBook)

A hydrodynamics-based approach to evaluating the risk of waterborne pathogens entering drinking water intakes in a large, stratified lake

Pathogen contamination of drinking water lakes and reservoirs is a severe threat to human health worldwide. A major source of pathogens in surface sources of drinking waters is from body-contact recreation in the water body. However, dispersion pathways of human waterborne pathogens from recreational beaches, where body-contact recreation is known to occur to drinking water intakes, and the associated risk of pathogens entering the drinking water supply remain largely undocumented. A high spatial resolution, three-dimensional hydrodynamic and particle tracking modeling approach has been developed to analyze the risk and mechanisms presented by pathogen dispersion. The pathogen model represents the processes of particle release, transport and survival. Here survival is a function of both water temperature and cumulative exposure to ultraviolet (UV) radiation. Pathogen transport is simulated using a novel and computationally efficient technique of tracking particle trajectories backwards, from a drinking water intake toward their source areas. The model has been applied to a large, alpine lake – Lake Tahoe, CA–NV (USA). The dispersion model results reveal that for this particular lake (1) the risk of human waterborne pathogens to enter drinking water intakes is low, but significant; (2) this risk is strongly related to the depth of the thermocline in relation to the depth of the intake; (3) the risk increases with the seasonal deepening of the surface mixed layer; and (4) the risk increases at night when the surface mixed layer deepens through convective mixing and inactivation by UV radiation is eliminated. While these risk factors will quantitatively vary in different lakes, these same mechanisms will govern the process of transport of pathogens.

English

Shallow borehole and dug well data are used in describing groundwater conditions in the vicinity of Abraka in the Nigerian coastal plain. Drill cuttings from ten boreholes show that the Abraka area is underlain by reddish brown unconsolidated sands, followed by a succession of grey- off-white medium grained sands of the Benin Formation. Hydraulic conductivity estimated from grain size analysis of cuttings obtained from typical borehole screened horizons range from 0.12 to 0.19 msec -1 . Regional groundwater flow is from north east to southwest with local distortions on this regional trend resulting from ground water abstraction in densely populated areas. Maximum TDS in ground water was recorded at 28 and 85 mg/l from dug wells. The trilinear plots of major ions in water indicate a mixing of mainly sodium chloride and calcium chloride water types. The stiff diagrams are also suggestive of possible stratification of water chemistry with depth. Borehole water quality is well within WHO and Nigerian drinking water quality standards while that from dug wells contains minimal levels of fecal coliform. Ground water and surface water are determined to be suitable for irrigation. It is also shown that the quality of water in the River Ethiope, TDS 6.6 to 8.09 mg/l, Escherichia coli occurrence at less than an average of 50 cfu/100 ml from selected recreation sites meets WHO standards for body contact recreation.

Quantitative Evaluation of the Impact of Bather Density on Levels of Human-Virulent Microsporidian Spores in Recreational Water

Microsporidial gastroenteritis, a serious disease of immunocompromised people, can have a waterborne etiology. During summer months, samples of recreational bathing waters were tested weekly for human-virulent microsporidian spores and water quality parameters in association with high and low bather numbers during weekends and weekdays, respectively. Enterocytozoon bieneusi spores were detected in 59% of weekend (n = 27) and 30% of weekday (n = 33) samples, and Encephalitozoon intestinalis spores were concomitant in a single weekend sample; the overall prevalence was 43%. The numbers of bathers, water turbidity levels, prevalences of spore-positive samples, and concentrations of spores were significantly higher for weekend than for weekday samples; P values were <0.001, <0.04, <0.03, and <0.04, respectively. Water turbidity and the concentration of waterborne spores were significantly correlated with bather density, with P values of <0.001 and <0.01, respectively. As all water samples were collected on days deemed acceptable for bathing by fecal bacterial standards, this study reinforces the scientific doubt about the reliability of bacterial indicators in predicting human waterborne pathogens. The study provides evidence that bathing in public waters can result in exposure to potentially viable microsporidian spores and that body contact recreation in potable water can play a role in the epidemiology of microsporidiosis. The study indicates that resuspension of bottom sediments by bathers resulted in elevated turbidity values and implies that the microbial load from both sediments and bathers can act as nonpoint sources for the contamination of recreational waters with Enterocytozoon bieneusi spores. Both these mechanisms can be considered for implementation in predictive models for contamination with microsporidian spores.

Protecting public health from the impact of body-contact recreation

Population growth and the increasing demand for recreational opportunities have put public and political pressure on water purveyors to make every water body available for multipurpose use. There is increasing evidence that full water-body contact recreation such as swimming, and water/jet skiing may add significantly more microorganisms such as viruses, Giardia, and Cryptosporidium to a water body when compared with non-body contact recreational waters. Body-contact recreation also poses a risk to the consumer inadvertently ingesting contaminated water. Waterborne disease outbreaks caused by recreation are well documented with the endemic rate and the risk level to the public estimated to be very high. Since 1989, 171 outbreaks, associated with recreational water, have been documented in the USA with more than 15,000 individuals infected; these outbreaks occurred in both natural and artificial settings. Discussions on the recently published Long-Term 2 Enhanced Surface Water Treatment Rule (LT2) have focused on varied treatment goals related to microbiological quality and source water protection methods at the heart of this discussion. This paper highlights new studies on risk from recreation, proposed beach standards, modeling to assess the risk of infection, political issues associated with limiting recreation, and what water utilities can do to reduce risk.

A public health evaluation of recreational water impairment

Water quality objectives for body contact recreation (REC-1) in Newport Bay, CA are not being attained. To evaluate the health implications of this non-attainment, a comprehensive health-based investigation was designed and implemented. Bacterial indicator data indicate that exceedances of the water quality objectives are temporally sporadic, geographically limited and most commonly occur during the time of the year and/or in areas of the bay where the REC-1 use is low or non-existent. A disease transmission model produced simulated risk estimates for recreation in the Bay that were below levels considered tolerable by the US EPA (median estimate 0.9 illnesses per 1,000 recreation events). Control measures to reduce pathogen loading to Newport Bay are predicted to reduce risk by an additional 16% to 50%. The results of this study indicate that interpreting the public health implications of fecal indicator data in recreational water may require a more rigorous approach than is currently used.

Incorporating susceptible subpopulations in microbial risk assessment: pediatric exposures to enteroviruses in river water.

The City of Stockton, California operates a wastewater treatment facility that discharges treated effluent to the San Joaquin River. During a recent discharge permit renewal, the question was raised whether pathogenic microorganisms in the effluent may cause an unacceptably high health risk for body contact recreation in the vicinity of the discharge. An investigation was initiated to characterize the risk to public health via body contact recreation in the San Joaquin River under various flow and treatment scenarios. In this investigation, a disease transmission model was applied to quantitatively characterize the relative risk associated with various treatment and flow scenarios for the City of Stockton's wastewater treatment facility. An important component of the investigation was to assess the feasibility of quantitatively characterizing the risk to highly susceptible subpopulations for effluent-related exposures to enteroviruses. This paper presents the methods used to conduct the feasibility assessment, the conclusions drawn for this project, and our recommendations to improve exposure assessments of susceptible subpopulations' contact with microbial pathogens in recreational water.

Predicted Public Health Consequences of Body‐contact Recreation ON A POTABLE WATER RESERVOIR

The Metropolitan Water District of Southern California recently completed construction of an 800,000 acre‐ft (1 × 109 m3) drinking water reservoir. Recreational activities, including swimming and other sports involving direct body contact (BC) with the water, have been the subject of considerable interest by local community members. Consequently, a modeling‐based risk assessment study was conducted to assess the potential public health consequences to downstream potable water users consuming water from this reservoir if BC recreation was permitted. Results of the study indicated that the annual risk of waterborne illness would increase three times above background, despite conventional treatment. Moreover, the occurrence of high‐loading pathogen events associated with BC recreation was observed to significantly increase the daily risk of waterborne illness to downstream consumers. The study also considered the cost of additional treatment that would be necessary to address the increased risk. The modeling approach used in this study provides guidance for policymakers and stakeholders who are examining issues associated with BC recreation and drinking water reservoirs.

Assessment of enteric pathogen shedding by bathers during recreational activity and its impact on water quality

An assessment was made to determine the potential loading of enteric pathogenic protozoa and viruses into drinking water supply reservoirs by body contact recreation. These and other organisms of fecal origin are shed from the body during bathing. A literature review was conducted on the concentration of selected enteric viruses and protozoa during infection, the incidence of these infections, and duration of excretion. In addition, from existing literature, the amount of fecal material released during bathing was estimated from the shedding of fecal coliforms by bathers. The mean amount of fecal material shed per bather was estimated at 0.14[emsp4 ]gram. The concentration of protozoan parasites (Giardia or Cryptosporidium) in feces of infected persons can range from 105 to 107 per gram and enteric viruses (enteroviruses, adenoviruses, rotavirus) from 105 to 1012 per gram. From this information, the concentration of enteric pathogens, shed into the water, could be calculated for a group of bathers. This information can be used to model the impact of body contact recreation on water quality in reservoirs used for drinking water supplies. Such information is useful in assessing the required treatment of the water to meet water quality regulations.

Modeling the impact of body-contact recreation on pathogen concentrations in a source drinking water reservoir

A modeling study was conducted to evaluate the impact of body-contact recreation (e.g., water skiing, jet skiing, swimming) on pathogen concentrations in a source drinking water reservoir under construction in eastern Riverside County in Southern California. A hybridized Monte Carlo-finite segment model was used to predict pathogen concentrations in the reservoir resulting from pathogen inputs associated with shed fecal material and accidental fecal releases (AFRs). Monte Carlo techniques were incorporated into the finite segment model to define characteristics about individual recreators which affect pathogen loading to the reservoir (e.g., infection, pathogen shedding rate, location). Results of simulations are provided in the form of cumulative distribution and probability density functions derived from uncertainty analyses. The model predicted considerable spatial and temporal variability in pathogen concentrations within the reservoir, with elevated levels of Cryptosporidium, rotavirus, and poliovirus in the epilimnion during periods of high recreational use. Predicted Giardia concentrations were lower than the other pathogens. Hypolimnetic concentrations of all pathogens were generally 1–3 orders of magnitude lower than the overlying epilimnetic concentrations. Model results also suggest that field sampling will underestimate the mean, range and variance of pathogen concentrations in the reservoir. The model was further modified to include a particle tracking scheme to allow for transport of aggregated fecal material. Results from simulations using this approach demonstrate a potential for high pathogen loads due to body-contact recreation periodically reaching treatment plants.

Bacterial water quality: Springs and streams in the Great Smoky Mountains National Park

Water samples from streams and springs in the Great Smoky Mountains National Park were analyzed for fecal coliform, fecal streptococcus, and total coliform bacteria. Levels of bacteria were found to be highly variable but related to elevation, time of year, type of water source, and water level of the streams. Visitors did not seem to be major contributors to bacterial contamination. Levels of fecal coliform and total coliform in most water samples were unsuitable for drinking without treatment. Tennessee state standards for body contact recreation (swimming and wading) were exceeded in a few samples but none from streams suitable for swimming. As a result of these findings, park managers increased efforts to inform visitors of the need to treat drinking water and removed improvements at backcountry springs which tended to give the springs the image of safe, maintained water sources.

COLIFORMS AND WATER QUALITY: USE OF DATA IN PROJECT DESIGN AND OPERATION1

ABSTRACT: Knowledge of coliform transport and disappearance may provide information for project design and operation that minimizes potential water quality problems such as the violation of body contact recreation standards. Storm events were sampled in the Caddo River above DeGray Reservoir, Arkansas, and then tracked through the reservoir using the increased turbidity associated with the storm flows. Fecal coliforms were sampled both in the river and throughout the water column in the reservoir. In general, increased fecal coliform concentrations were closely associated with the increased turbidity resulting from the storm flows. This association existed for all three types of turbidity plume movement ‐ overflow, interflow, and underflow. As the turbidity plume moved down the reservoir, fecal coliform concentrations decreased due to die‐off, settling, and dilution. With several assumptions, it is possible to use this information to assist in locating recreational sites in a reservoir or to anticipate possible body contact standard violations at existing recreation sites.

CONCENTRATION AND SOURCES OF FECAL AND ORGANIC POLLUTION IN AN AGRICULTURAL WATERSHED1

ABSTRACT: Fecal contamination and organic pollution of an agricultural drainage in northeast Indiana was high. Bacterial counts (total coliform, TC; fecal coliform, FC; and fecal streptococcus, FS) and biochemical oxygen demand (BOD) were used to assess waste concentrations. Coliform counts indicated that sections of the drainage receiving septic effluent had waste concentrations far in excess of public health standards (mean FC = 550,000/100 ml). Areas of drainage remote from septic tank pollution were found to occasionally meet federal public health standards for whole body contact recreation but generally these areas had twice the allowable limit of 200 FC/100 ml. Bacterial contamination was highest during runoff events when the median values for TC, FC, and FS were 5, 3, and 17 times greater, respectively, than the median values during low stream discharge. Surface flows carried contaminants from unconfined livestock operations and fecally contaminated sediment was transported by high waters. During one runoff event a BOD loading of 36.7 kg/km2 was recorded and the peak BOD concentration observed was 16 mg/l. A discharge of liquid manure from a confined livestock operation caused a major fish kill. Pollution from septic tanks and unconfined livestock is greatest at high stream discharge when dilution reduces the impact on aquatic life.