Authors: B. B. Ross, Professor, Dept. of Biological Systems Engineering, VPI&SU, Blacksburg, Virginia; L. S. Allison, Extension Agent, Accomack County, Accomac, Virginia; J. N. Belote, Extension Agent, Accomack County, Accomac, Virginia; J. F. Diem, Extension Agent, Northampton County, Exmore, Virginia; B. E. Holden, Extension Agent, Northampton County, Exmore, Virginia; P. L. Kellam, Extension Agent, Northampton County, Exmore, Virginia; P. M. Milbourne, Extension Agent, Accomack County, Accomac, Virginia; K. R. Parrott, Associate Professor, Dept. of Near Environments, VPI&SU, Blacksburg, Virginia; and A. C. Bourne, Graduate Research Assistant, Dept. of Biological Systems Engineering, VPI&SU, Blacksburg, Virginia
Publication Number 442-936, March 2003
Table of Contents
Abstract
Acknowledgments
Introduction
Objectives
Methods
Findings and Results
Conclusions
References
Appendix
Following completion of the programs, a survey was mailed to the 353 participants. One hundred and ninety-seven participants returned survey forms on which they identified their reason(s) for participating in such a program; the primary reason was concern about safety of their water supply. Returned survey forms also provided insight into measures participants had already taken, or planned to take, to improve the quality of their water supply. Nearly two-thirds of the households who reported having at least one water quality problem had taken, or planned to take, at least one measure to improve the quality of their water supply. Ten percent or more of all participants had taken, or planned to take, one or more of the following actions: purchase or rent water treatment equipment, use bottled water drinking/cooking, and contact a state agency for further assistance.
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The Boards of Supervisors of both counties are acknowledged for their financial support of the program. The Southeast Rural Community Assistance Project, Inc. of Roanoke, Virginia also provided funding to offset the cost of testing that was assessed to all participants. CSREES/USDA Water Quality Program Support 3-d funds were also made available for this program.
The Water Quality Laboratory of the Department of Biological Systems Engineering at Virginia Tech was responsible for the majority of the water quality analyses, as well as coordination among the various labs and for much of the data management. Julie Jordan, Laboratory Supervisor, and her staff are especially acknowledged for their efforts. Assisting with the general water chemistry analysis was the Soils Testing Laboratory of the Department of Crop and Soil Environmental Sciences at Virginia Tech.
Additional support from Virginia Tech should also be noted. Judy Poff, of the Virginia Water Resources Research Center, was instrumental in providing educational publications for participants at the public meetings. Joe Gray, of the Virginia Cooperative Extension Distribution Center, is appreciated for his assistance in preparing and mailing the evaluation survey packets to participants. Appreciation is due Diane Mahaffey for her efforts in preparing project forms and in typing this manuscript, and to Lori Yates for her assistance in data management. In addition, Bev Brinlee and Tim FisherPoff are acknowledged for their editorial and design contributions.
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Throughout these two counties, most wells were drilled only for farm or domestic water supply. George and Gray (1988) have estimated that 95% of the drilled wells are inadequately constructed, while essentially all dug/bored wells are inadequate. Seven percent of households were also estimated to have failing or inadequate waste disposal systems.
Accomack and Northampton Counties have a combined land area of 662 square miles. Both counties comprise the Eastern Shore of Virginia, a peninsula bordered by Maryland to the north, the Chesapeake Bay to the west, and the Atlantic Ocean to the east. Although within the Coastal Plain physiographic province, there are no major river basins on the Eastern Shore, which is drained by many small streams westward and eastward from the central ridge into tidal estuaries of the Chesapeake Bay and Atlantic Ocean, respectively.
The population of the two-county area decreased by more than 2% during the period 1980-90. Despite this population decline, the total number of housing units increased by 15%, and some new homesites are rural-based without public water and sewage services. As rural home sites encroach on agricultural land, the water supply becomes suspect to residents. Of equal importance is the potential failure of septic systems, since a number of home sites are on land less than ideal for a properly functioning septic system.
In addressing similar concerns, Ross et al. (1991) initiated a pilot program of household water quality education in Warren County, Virginia, which included water sampling, testing, and diagnosis. Based on requests and support from local interests, subsequent programs have been conducted in 62 additional counties. During the course of these projects, nearly 9,500 households submitted water samples through local Virginia Cooperative Extension Offices to be analyzed for the following: iron, manganese, hardness, sulfate, chloride, fluoride, total dissolved solids, pH, saturation index, copper, sodium, nitrate, and total coliform and fecal coliform/E. coli bacteria.
Major household water quality problems identified, as a result of these previous analyses, were determined to be iron/manganese, hardness, fluoride, and total dissolved solids, and because of their potential health significance, corrosivity, bacteria, and to a lesser extent, sodium and nitrate, although the occurrence and extent of these problems varied across counties. In most county programs, a limited number of additional samples from "high-risk" households were tested for over two dozen pesticides and other chemical compounds. Most of these compounds have been detected in measurable quantities in one or more samples, with several values exceeding a corresponding U.S. Environmental Protection Agency Health Advisory Level (HAL) or Maximum Contaminant Level (MCL). It was the need to assess the current state of rural household water supplies in Accomack and Northampton Counties, in addressing the above water quality issues, that led to the implementation of the Household Water Quality Education Program in both counties.
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The programs were launched through local meetings held in Accomack County (Melfa) and Northampton County (Eastville) in mid-October. Attendees of these initial meetings were presented with information on local hydrogeologic characteristics in relation to groundwater pollution, likely sources of, and activities contributing to, groundwater contamination, the nature of household water quality problems (both nuisance and health-related), and specifics of the water testing program to follow. At these meetings, individuals were invited to sign up to participate in the testing program at a basic cost of $20 per household water sample submitted.
Provisions were made to analyze up to 250 household water samples in Accomack County and 150 in Northampton County. Water sampling kits, for use by the participants themselves, were made available at the meetings and at the county Cooperative Extension offices after the meetings for late registrants. Two types of water sampling kits were distributed: (1) general water chemistry analysis for iron, manganese, hardness, sulfate, chloride, fluoride, total dissolved solids, pH, saturation index (Langlier), copper, sodium, and nitrate; and (2) bacteriological analysis (total coliform and E. coli).
The sampling kits included a 250 ml plastic bottle for general water chemistry samples and a sample identification form (see Appendix). The form included sampling instructions and a questionnaire on which participants were asked to describe the characteristics of their water supply. Also included in the kits was a 125 ml sterilized plastic bottle for bacteriological samples. Instructions called for sampling from a drinking water tap and for flushing water systems prior to sampling to minimize contaminants contributed by the plumbing system. Persons who already had a water treatment device, such as a water softener, were requested to provide information about the type of equipment so that effective evaluation of their water quality and proper interpretation of results could be obtained, as further explained below.
Water samples were collected on November 1 and 15 in both counties. At the close of each collection day, all samples were packed in ice and immediately delivered to Virginia Tech in Blacksburg for analysis.
The general water chemistry and bacteriological analysis was coordinated by the Department of Biological Systems Engineering Water Quality Laboratory at Virginia Tech. The Soils Testing Laboratory of the Department of Crop and Soil Environmental Sciences at Virginia Tech was subcontracted to analyze samples for several of the constituents. Water quality analyses were performed using standard analytical procedures (USEPA, 1979).
After the analysis had been completed for each county, participants were reminded by mail to attend subsequent meetings in either Eastville or Melfa to obtain and discuss the test results and management practices to reduce or prevent water contamination. Complete test results were ultimately mailed to those participants who could not attend any of the meetings. A sample report form and accompanying report interpretation are shown in the Appendix.
At the conclusion of the programs, an evaluation survey was mailed to participants (see Appendix). The objectives of the survey were to determine (1) the reasons for participation in the educational programs and for having household water tested, and (2) the actions to correct water quality problems the participants had taken, or planned to take, as a result of participation in the programs. Limited socio-economic information was also requested to obtain a profile of the total audience reached by the programs.
In addressing overall project objective 2, local government and public officials were kept apprised of water quality test results, during the course of the programs and at their completion. While the project was designed to involve voluntary participation, and quality control in sampling was not assured, the information gathered was nevertheless deemed useful for water quality assessment and planning at county and regional levels.
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Profile of Participant Households
The average length of the respondents' residence in Accomack or Northampton Counties was 14 years. The length of residence reported ranged from 1 to 79 years. Thirty-two percent of those responding had lived in their present county for 5 years or less. The size of the respondents' households ranged from one to six members; average household size was 2.18. It can, therefore, be estimated that more than 750 residents of the two counties were directly impacted by the water analysis/diagnosis aspect of the programs.
More than one-half (56%) of the respondents were college graduates and 93% had at least a complete high school education (see Figure 1); facts that are not surprising, since it is likely that such individuals would have a greater awareness and understanding of water quality issues and be more likely to participate in such a program.
Participation in the program was on the high end of income distribution. Figure 2, which shows the family income (before taxes) of the respondents, indicates that a likely majority of the respondents exceeded the median family income ($23,845 averaged for the two counties and according to the 1990 Census) (Koebel et al., 1993). Twenty percent of respondents declined to indicate family income.
Profile of Household Water Supplies
The initial survey answers, provided by all 353 participants in the water testing programs, helped to characterize their water supplies (see Appendix). One set of questions dealt with the proximity of the household water supply to potential sources of groundwater contamination. One such question sought to define housing density, which may have an impact primarily from the standpoint of contamination from septic systems and related water quality problems. Participants were asked to classify their household environs as one of the following four categories, ranging from low to high density: (1) on a farm, (2) on a remote, rural lot, (3) in a rural community, and (4) in a housing subdivision. As shown in Figure 3, rural community was the most common at 52%, while subdivision (11%) was the least common.
Participants were also asked to identify potential contamination sources within 100 feet of their water supply. The major sources identified were septic system drainfields, streams, and home heating oil storage tanks, noted by 28%, 22% and 21% of all households, respectively. Indications of proximity (within one-half mile) to larger activities which could potentially contribute to groundwater pollution were also sought. Agricultural activities were the most commonly identified; 65% of the participants indicated that their water supply was located within one-half mile of field crop production and 8% within one-half mile of a major farm animal operation.
Information was also obtained regarding characteristics of the participants' water supply systems. Regarding the type of water source supplying the household, all of the participants reported that they rely on a well. Participants were asked to provide an estimate of the well depth, if known. Of those participants indicating well depths, 88% reported depths of more than 50 feet, while 12% reported less than or equal to 50 feet. The maximum well depth reported was 300 feet; the average well depth was 149 feet. Ten percent of the wells were constructed in or prior to 1970. The earliest reported well construction date was 1900.
Household water systems were further identified with respect to the type of material used in the piping network for water distribution throughout the dwellings. The most widely used material was copper (47%), while plastic was reported by 38% of the participants. Ten percent of participants reported, "Don't know."
To properly evaluate the quality of water supplies in relation to the point of sampling, participants were asked if their household water systems had water treatment devices currently installed, and if so, the type of device. The results of the inquiry are presented in Figure 4. Twenty-four percent of the participants reported at least one treatment device installed, with the most common type of treatment device in use being a water softener (66%) followed by sediment filter (30%).
Participants' Perceptions of Household Water Quality
Participants were also asked about problems they were experiencing in their household water systems (see Appendix). They were asked initially whether or not they experienced one or more of the following conditions: (1) corrosion of pipes or plumbing fixtures; (2) unpleasant taste; (3) objectionable odor; (4) unnatural color or appearance; (5) floating, suspended, or settled particles in the water; and (6) staining of plumbing fixtures, cooking appliances/utensils or laundry. With the exception of (1) above, with which 16% of the participants identified, participants were given several more specific descriptions from which to choose if answering positively.
Twenty percent of the participants responded that their water had an unpleasant taste. For these participants, the identification of tastes is presented in Figure 5. "Sulfur" taste was the most common problem (44%), followed by "metallic", identified by 32% of those who reported taste problems. Seventeen percent of those with taste problems indicated "other" including such a description as flat.
An objectionable odor was reported by 26% of the participants. Of these, the description of odors selected is shown in Figure 6. The most prevalent odor described, by far, was "rotten egg," or sulfur, identified by 72% of those reporting odor problems. Thirteen percent reported "other" odors, such as fishy.
Twelve percent of the participants affirmed their water had an unnatural color or appearance. "Yellow" was identified by 44% of those who reported appearance problems (Figure 7), followed by "milky" and "muddy" at 20% and 17%, respectively. Ten percent offered their own descriptions by selecting "other" to include brownish.
A related question sought to identify the presence of solid particles in participants' water supplies. Sixteen percent described such a condition; more than one-half of these (54%) reported that they noticed "white flakes" in their water (Figure 8). Seven percent indicated "other," including such a description as sand.
Staining problems on plumbing fixtures, cooking appliances/utensils, and/or laundry were reported by 56% of the participants. As presented in Figure 9, the major problem, by far, was that of "rusty" identified by 89% of those with staining problems.
Household Water Quality Analysis
Ultimately, two sample groups resulted: the "tap water" and "raw water" samples. The "tap water" group consisted of the 353 individual household water supplies analyzed to represent the actual water quality at the drinking water tap (including treated water). The "raw water" group consisted of samples from untreated systems only - a total of 261 samples.
The raw water sample results presented below may not be entirely indicative of the status of raw groundwater quality in Accomack and Northampton Counties. This may be particularly true for many of the nuisance contaminants for which treatment systems have been installed, since many of the already treated supplies likely represented the worst cases for specific contaminants correctable by treatment devices. Therefore, the inclusion of actual raw water (before treatment) analyses, if they had been available from those households with treatment devices installed, would likely have tended to worsen the overall assessment of raw water quality in the two counties.
General Water Chemistry Analysis
The tests included in the general water chemistry analysis are listed in Table 1, along with the detection limits, where appropriate, for each test as determined by laboratory equipment and testing procedure constraints. Also presented are the averages and ranges for each sample group defined for both counties combined. Table 2 provides, for both sample groups and each county, as well as both counties combined, the percentage of constituent values exceeding a given water quality standard or guideline. The results and importance of each test for both of the sample groups are individually discussed below.
Table 1. Average and range of concentration of contaminants comprising general water chemistry analysis for Accomack and Northampton Counties.
| Test | Detection Limit | Measured Concentrations | |||||
|---|---|---|---|---|---|---|---|
| Raw Water (n=261) | Tap Water (n=353) | ||||||
| Avg.1 | Min. | Max. | Avg. | Min. | Max. | ||
| Iron (mg/L) | 0.005 | 0.359 | DL2 | 7.920 | 0.331 | DL | 7.920 |
| Manganese (mg/L) | 0.001 | 0.035 | DL | 1.803 | 0.030 | DL | 1.803 |
| Hardness (mg/L) | 0.3 | 110.9 | DL | 1050.7 | 95.0 | DL | 1050.7 |
| Sulfate (mg/L) | 0.3 | 8.7 | DL | 134.5 | 10.8 | DL | 293.0 |
| Chloride (mg/L) | 40.0 | 19.0 | DL | 743.0 | 65.0 | DL | 1250.0 |
| Fluoride (mg/L) | 0.5 | 0.56 | DL | 1.97 | 0.57 | DL | 1.97 |
| TDS (mg/L) | 1.0 | 275.0 | 62.0 | 1840.0 | 291.0 | 29.0 | 2930.0 |
| pH | - | 7.57 | 5.93 | 8.20 | 7.61 | 5.93 | 8.50 |
| Saturation Index | - | -0.79 | -4.16 | 0.07 | -0.99 | -4.88 | 0.48 |
| Copper (mg/L) | 0.002 | 0.012 | DL | 0.469 | 0.014 | DL | 0.469 |
| Sodium (mg/L) | 0.01 | 41.87 | 4.14 | 334.10 | 53.33 | 4.14 | 961.00 |
| Nitrate (mg/L) | 0.005 | 0.430 | DL | 11.433 | 0.597 | DL | 27.307 |
| 1Averages calculated on the basis of below detection limit (DL) values set equal to the DL. 2Sample concentration non-detectable, i.e., below the detection limit for the given contaminant. | |||||||
Table 2. Percent of concentrations exceeding established standards for contaminants comprising general water chemistry and bacteriological analysis for Accomack and Northampton Counties.
| Test | Standard | Percent of Values Exceeding Standard | |||||
|---|---|---|---|---|---|---|---|
| Row Water | Tap Water | ||||||
| Total n=261 | Acc. n=175 | Nor. n=86 | Total n=353 | Acc. n=233 | Nor. n=120 | ||
| Iron (mg/L) | 0.3 | 28.7 | 30.3 | 25.6 | 25.5 | 27.5 | 21.7 |
| Manganese (mg/L) | 0.05 | 17.2 | 15.4 | 20.9 | 15.9 | 14.2 | 19.2 |
| Hardness (mg/L) | 180.0 | 3.8 | 4.0 | 3.5 | 3.7 | 3.4 | 4.2 |
| Sulfate (mg/L) | 250.0 | 0 | 0 | 0 | 0.3 | 0 | 0.8 |
| Chloride (mg/L) | 250.0 | 3.1 | 3.5 | 2.4 | 3.1 | 3.0 | 3.3 |
| Fluoride (mg/L) | 2/4 | 0/0 | 0/0 | 0/0 | 0/0 | 0/0 | 0/0 |
| TDS (mg/L) | 500.0 | 8.4 | 9.1 | 7.0 | 8.2 | 8.6 | 7.5 |
| pH - Low | 6.5 | 3.4 | 1.1 | 8.1 | 3.1 | 0.9 | 7.5 |
| pH - High | 8.5 | 0 | 0 | 0 | 0 | 0 | 0 |
| Saturation Index - Low | -1.0 | 14.2 | 8.6 | 25.6 | 25.5 | 19.7 | 36.7 |
| Saturation Index - High | +1.0 | 0 | 0 | 0 | 0 | 0 | 0 |
| Copper (mg/L) | 1.0/1.3 | 0/0 | 0/0 | 0/0 | 0/0 | 0/0 | 0/0 |
| Sodium (mg/L) | 20.0 | 43.3 | 48.5 | 32.5 | 53.3 | 58.0 | 44.1 |
| Nitrate (mg/L) | 10.0 | 0.4 | 0 | 1.2 | 1.1 | 0 | 3.3 |
| Total Coliform | ABSENT | 21.8 | 21.7 | 22.1 | 22.4 | 23.2 | 20.8 |
| E. coli | ABSENT | 2.7 | 2.9 | 2.3 | 2.3 | 2.1 | 2.5 |
Iron. Iron in water does not usually present a health risk. It can, however, be very objectionable if present in amounts greater than 0.3 mg/L. Excessive iron can leave brown-orange stains on plumbing fixtures and laundry. It may give water and/or beverages a bitter metallic taste and may also discolor beverages.
Overall, 26% of samples in the tap water and 29% of samples in the raw water sample groups had iron concentrations exceeding the U.S. Environmental Protection Agency (EPA) Secondary Maximum Contaminant Level (SMCL) of 0.3 mg/L. It should be noted that the occurrence of excessive iron was slightly greater for Accomack County as compared to Northampton County (Table 2). The presence of iron was not surprising in view of the generally accepted notion that excessive iron is prevalent in rural water supplies throughout much of Virginia. Only 3% of the participants reported the installation of an iron removal filter, however, water softeners, which can remove small amounts of iron, as well as manganese, had been installed in 16% of the households. Despite the treatment equipment in place, the results of the sample questionnaire (see Appendix) revealed that 89% of the 196 who reported staining problems, or 49% of all participants, classified the color of those stains as "rusty" (red/orange/brown). Stains of this color on plumbing fixtures, cooking appliances/utensils, and/or laundry are usually attributed to excessive iron concentrations.
It should be noted that the SMCL for iron is likely based more on taste considerations than long-term staining tendencies, particularly on plumbing fixtures. It has been suggested that concentrations below 0.1 mg/L are preferred, when stain prevention is of concern. When a value of 0.1 mg/L was used as the threshold concentration, an additional 28% of samples in the tap water and 32% of samples in the raw water sample groups of both counties combined exceeded this limit.
Manganese. Manganese does not present a health risk. However, if present in amounts greater than 0.05 mg/L, it may give water a bitter taste and produce black stains on laundry, cooking utensils, and plumbing fixtures.
The results of these analyses indicated that the extent of manganese problems in the two counties was slightly less than that of iron, with 16% and 17%, respectively, of the tap water and raw water samples exceeding the SMCL. It should be noted that a higher percentage of these samples were from Nothampton County (Table 2). While manganese stains are generally dark and only 4% of all participants indicated "black" stains, the "particles in water" description of "black specks," reported by 3% of all participants, may also provide evidence of excessive manganese concentrations.
Hardness. Hardness is a measure of calcium and magnesium in water. Hard water does not present a health risk. However, it keeps soap from lathering, decreases the cleaning action of soaps and detergents, and leaves soap "scum" on plumbing fixtures, and scale deposits in water pipes and hot water heaters. Softening treatment is highly recommended for very hard water (above 180 mg/L). Water with a hardness of about 60 mg/L or less does not need softening.
Hardness is an additional "natural" parameter usually linked to karst terrain and limestone formations that are not prevalent in this region of Virginia. The exception to this rule is in far eastern Virginia where ancient maine deposits have provided a source of calcium. As mentioned above, 16% of all participants had installed a water softener (Figure 4), however, only 4% of samples in both sample groups exceeded the maximum recommended hardness level of 180 mg/L.
Hardness tolerance, like that of many nuisance contaminants, is somewhat relative to individual preferences. For example, water with total hardness between 60 mg/L and 180 mg/L may warrant the installation of a commercial water softener in the view of some household water users while others are satisfied with untreated water. Seventy-two percent of the tap water samples and 84% of the raw water samples of both counties combined were in the range of 60 mg/L to 180 mg/L total hardness, indicating that more than three-fourths of all samples could be classified as "moderately hard" or harder.
Sulfate. High sulfate concentrations may result in adverse taste or may cause a laxative effect. The SMCL for sulfate is 250 mg/L. Sulfates are generally naturally present in groundwater and may be associated with other sulfur-related problems, such as hydrogen sulfide gas. This gas may be caused by the action of sulfate-reducing bacteria, as well as by other types of bacteria (possibly disease-causing bacteria) on decaying organic matter. While it is difficult to test for the presence of this gas in water, it can be easily detected by its characteristic "rotten egg" odor, which may be more noticeable in hot water. Water containing this gas may also corrode iron and other metals in the water system and may stain plumbing fixtures and cooking utensils.
Sulfate concentrations were relatively low for both the raw water and tap water sample groups. Only one of the tap water samples (from Northampton County) exceeded 250 mg/L. The complaints of a "rotten egg/sulfur" odor by nearly three-fourths of those reporting odor problems indicate that hydrogen sulfide gas may be a somewhat widespread problem in household water systems in the two counties; a conclusion that can not be confirmed by the presence of sulfate.
Chloride. Chloride in drinking water is not a health risk. With the possible exception of coastal areas, natural levels of chloride are generally low, and high levels in drinking water may indicate contamination from a septic system, road salts, fertilizers, industry, or animal wastes. High levels of chloride may speed corrosion rates of metal pipes and cause pitting and darkening of stainless steel. The EPA has set an SMCL for chloride of 250 mg/L. Three percent of the tap water and raw water samples exceeded the SMCL for chloride.
Fluoride. Fluoride is of concern primarily from the standpoint of its effect on teeth and gums. Small concentrations of fluoride are considered to be beneficial in preventing tooth decay, whereas moderate amounts can cause brownish discoloration of teeth, and high fluoride concentrations can lead to tooth and bone damage. For these reasons, the EPA has set both a SMCL of 2 mg/L and a Maximum Contaminant Level (MCL) of 4 mg/L. None of the samples in the tap water and raw water sample groups exceeded either standard.
Total Dissolved Solids (TDS). High concentrations of dissolved solids may cause adverse taste effects and may also deteriorate household plumbing and appliances. The EPA SMCL is 500 mg/L total dissolved solids. Average TDS concentrations were 275 mg/L and 291 mg/L for the raw water and tap water sample groups, respectively. Eight percent of samples in each sample group exceeded the standard. The maximum TDS concentrations among the raw water and tap water samples were 1840 mg/L and 2930 mg/L, respectively.
pH. The pH indicates whether water is acidic or alkaline. Acidic water can cause corrosion in pipes and may cause toxic metals from the plumbing system to be dissolved in drinking water. The life of plumbing systems may be shortened due to corrosion, requiring expensive repair and replacement of water pipes and plumbing fixtures. Treatment is generally recommended for water with a pH below 6.5. Alkaline water with a pH above 8.5 is seldom found naturally and may indicate contamination by alkaline industrial wastes. The EPA has set a suggested range of between 6.5 and 8.5 on the pH scale for drinking water.
The average pH reading was 7.6 for both the tap water and raw water samples. None of the samples in either sample group exceeded a pH of 8.5, with a maximum pH value of 8.5. Three percent of both the tap water and raw water samples had a pH value of less than 6.5, with a majority of these from Northampton County. While the remaining samples had a pH above 6.5, slightly acidic water with a pH between 6.5 and 7.0 can lead to less immediate staining and corrosion problems. An additional 4% and 5% of samples in the tap water and raw water sample groups, respectively, fell into this category.
Saturation Index. The saturation index (Langlier) is used, in addition to pH, to evaluate the extent of potential corrosion of metal pipes, plumbing fixtures, etc. It is a calculated value based on the calcium concentration, total dissolved solids concentration, measured pH, and alkalinity. A saturation index greater than zero indicates that protective calcium carbonate deposits may readily form on pipe walls. A saturation index less than zero indicates that the water does not have scale-forming properties and pipes may be subject to corrosion. Saturation index values between -1 and +1 are considered acceptable for household water supplies.
No saturation index values were determined to be above +1 in either sample group. Values of less than -1, however, were determined for 26% of the tap water samples and 14% of the raw water samples with a majority of these from Northampton County. Average saturation index values were -0.99 for the former and -0.79 for the latter sample group with minimum values of -4.88 for the tap water samples and -4.16 for the raw water samples. There is an apparent partial explanation for this discrepancy. It is well documented that water softeners, which impacted 16% of the tap water samples, tend to enhance corrosion potential by removing scale-forming calcium from the water. For this reason, as well as the additional sodium imparted to the water (see below), it is sometimes recommended that water softeners be installed for hot water only or, in the case of extremely hard water, that at least drinking water lines bypass the softening equipment.
Copper. The EPA health standard for copper in public drinking water supplies is 1.3 mg/L, the maximum level recommended to protect people from acute gastrointestinal illness. Even lower levels of dissolved copper may give water a bitter or metallic taste and produce blue-green stains on plumbing fixtures. Consequently, EPA has established an SMCL for copper of 1.0 mg/L in household water.
None of the tap or raw water samples exceeded the recommended health level of 1.3 mg/L or the SMCL of 1.0 mg/L. The maximum copper concentration measured was 0.47 mg/L. Since natural levels of copper in groundwater are low, and the primary contributor of copper in drinking water is corrosion of copper water pipes and fittings, low copper levels were expected, even in the case of tap water samples, assuming that water lines were flushed properly prior to sampling.
Sodium. Sodium may be a health hazard to people suffering from high blood pressure or cardiovascular or kidney diseases. For those on low-sodium diets, 20 mg/L is suggested as a maximum level for sodium in drinking water, although a physician should be consulted in individual cases. Average sodium concentrations were 53 mg/L and 42 mg/L for the tap water and raw water sample groups, respectively, while the maximum concentration was 961 mg/L in the former case and 334 mg/L in the latter case. For the tap water and raw water samples, respectively, 53% and 43% exceeded 20 mg/L with a majority of these samples from Accomack County (Table 2). Although in coastal areas much of the excessive sodium found in well water supplies can be deemed "natural", part of these discrepancies were likely primarily due to the impact of installed water softeners on the tap water sample group (16% of all participants reported the use of a water softener).
It should be reemphasized, however, that the suggested threshold of 20 mg/L for sodium is relatively low and applicable only to individuals suffering from health problems, such as heart disease or high blood pressure. To evaluate the presence of high sodium levels in the context of an otherwise healthy individual, a threshold value of 100 mg/L sodium has been suggested. Eleven percent of the raw water and 14% of the tap water samples exceeded this 100 mg/L threshold. Again, the likely influence of water softeners on sodium concentrations can be seen, even under higher threshold value.
Nitrate. High levels of nitrate may cause methemoglobinemia or "blue-baby" disease in infants. Though the EPA has set a MCL for nitrate (as N) of 10 mg/L, it suggests that water with greater than 1 mg/L not be used for feeding infants. Levels of 3 mg/L or higher may indicate excessive contamination of the water supply by commercial fertilizers and/or organic wastes from septic systems or farm animal operations, which may be subject to seasonal and climatic influences.
The maximum concentration of nitrate obtained was 27.3 mg/L for the tap water and 11.4 mg/L for the raw water sample groups. Only four of the tap water samples (all from Northampton County) and one of the raw water samples exceeded the MCL of 10 mg/L. Thus, serious nitrate contamination does not appear to be a widespread problem in either county. When a 1 mg/L threshold value was selected, however, a higher occurrence of nitrate was determined. In this case, 8% of the tap water and 6% of the raw water samples exceeded the level of potential concern to infant health. Furthermore, 6% of the tap water and 5% of the raw water samples had nitrate concentrations exceeding 3 mg/L, indicating that health-impacting levels would likely be approached in a number of cases in both counties. In both of the non-standard threshold cases, incidences of excessive nitrate were substantially higher for Northampton County than for Accomack County.
Bacteriological Analysis
A common hazard of private household water supplies is contamination by potentially harmful bacteria and other microorganisms. Microbiological contamination of drinking water can cause short-term gastrointestinal disorders, such as cramps and diarrhea, that may be mild to very severe. Of the non-gastrointestinal disorders, one particularly important disease transmissible through drinking water is Viral Hepatitis A. Other diseases include salmonella infections, dysentery, typhoid fever, and cholera.
Coliform bacterial detection is simply an indication of the possible presence of pathogenic, or disease-causing organisms. Detection of coliform bacteria is confirmed by a total coliform analysis result above zero. Coliforms are always present in the digestive systems of all warm-blooded animals and can be found in their wastes. Coliforms are also present in the soil and in plant material. While a water sample with total coliform bacteria present may have been inadvertently contaminated during sampling, other possibilities include surface water contamination due to poor well construction, contamination of the household plumbing system, or water table contamination. To determine whether or not the bacteria were from human and/or animal waste, positive total coliform tests were followed up by an analysis for E. coli bacteria. Therefore, most probable number quantitative bacteria counts were obtained for both total coliform and E. coli bacteria.
Of the 353 household water samples from the two counties analyzed for total coliform bacteria, 79 (22%) tested positive (present). Subsequent E. coli analysis for these total coliform positive samples resulted in 8, or 10%, positive results, or 2% of all household water samples undergoing bacteriological analysis. The percentages of positive total coliform and E. coli results for the raw water sample group were 22 and 3, respectively. Quantitative bacteria counts ranged from zero up to the detection limit of 2400 colonies/100ml for total coliform and 39 colonies/100ml for E. coli bacteria.
The susceptibility of household water supplies to bacteriological contamination has often been associated with the type of water source. For example, it is generally accepted that the likelihood of bacteriological contamination of springs is greater than that of well water supplies, which usually offer better protection from surface, or near surface, contaminants. Similarly, deep drilled wells are better protected than shallow dug and bored wells. This contention is clearly borne out by the results of this program, which indicated that the incidence of total coliform and E. coli contamination of dug/bored wells was 25% and 8%, respectively, while for drilled wells, positive total coliform and E. coli results were obtained for 20% and 1% of the samples.
The age of a water source/system is an additional factor which may have an influence on contamination susceptibility. With respect to wells in particular, deterioration of the well structure over time, cumulative damage caused by equipment traffic, etc., and prolonged exposure of the wellhead area to potentially harmful pollutants may all contribute to the eventual contamination of the well. A major age-related impact could relate to the development of, and conformance with, well construction standards through the years. Major legislation in Virginia to address such issues has been enacted in recent years, most notably in the early 1970's and early 1990's. Therefore, for the purpose of examining the occurrence of bacteriological contamination with well age, the sample results were evaluated for the following three construction date categories: (1) pre-1970, (2)1970-1989, and (3) 1990 to date. With respect to total coliform bacteria, for each of the above categories, the percentages of well water samples determined to be positive were as follows: (1) 15, (2) 24, and (3) 27. For E. coli bacteria, the corresponding percentages were: (1) 4, (2) 3, and (3) 1. For E. coli bacteria specifically, an overall improvement was noted with time, likely influenced not only by the newness of the wells, but also recent legislation.
Fecal bacteria present in household water supplies may have originated from animal waste generation or human waste from septic systems. Although, positive results should be viewed with concern, they are not a cause for panic. Individuals have probably been drinking this water for some time with no ill effects and could possibly continue to do so. Nevertheless, such problems should be further investigated and remedied, if possible. Program participants whose water tested positive were given information regarding emergency disinfection, well improvements, septic system maintenance and other steps to correct the source of contamination. After taking initial corrective measures, they were advised to have the water retested for total coliform, followed by E. coli tests, if warranted.
Post-Program Survey
Following the completion of the educational program, a survey form (see Appendix) was mailed to the 353 households whose water supply had been tested. The objectives of the survey were to determine: 1) reasons for program participation and for having water tested, and 2) what the respondents had done to correct water quality problems as a result of participation in the educational program. One hundred and nintey-seven (56%) had returned the survey forms by the deadline.
Household Water Testing History
Participants were asked to indicate their previous experience with water testing and, specifically, if and when they had last had a laboratory analysis of their present household water supply. Twenty-six percent of the respondents indicated that they had previously obtained water test results. Of those reporting a prior testing date, 60% had done so within the past five years and 19% within the past two years.
Reasons for Program Participation
People participated in the water quality program for one or more reasons. Seventy-four percent of the respondents were prompted to participate by concern about the safety of their water supply. Thirty-seven percent of the respondents were prompted by nuisance problems, such as staining, objectionable taste and odor, etc. Ten percent wanted to follow up on previous tests of their household water. Nineteen percent cited other reasons, such as general curiosity and low-cost opportunity.
Follow-up Activities Taken or Planned
Participants were asked to indicate the measures they planned to take, or had already taken, to improve the quality of their water supply, since receiving the results of their water quality analysis. Table 3 presents the results of this inquiry, with the greatest number of households (10% or more) indicating that they had already taken, or planned to take, one or more of the following actions: purchase or rent water treatment equipment, use bottled water for drinking/cooking, and contact a state agency for further assistance.
Table 3. Measures taken or planned by respondents, since water quality analysis, to improve water supply (Accomack and Northampton Counties)
| Measure | Percent of Respondents who Respondents (n=197) | Percent of Respondents who Reported the Following Problems | |||
|---|---|---|---|---|---|
| Health Only (n=69) | Nuisance Only (n=25) | Health & Nuisance (n=29) | None (n=74) | ||
| Contact an Agency, such as the Health Department | 9.6 | 13.0 | 8.0 | 27.6 | 0 |
| Seek Additional Water Testing from Another Lab | 5.6 | 8.7 | 4.0 | 13.8 | 0 |
| Determine Source of Undesirable Condition | 6.1 | 8.7 | 4.0 | 10.3 | 2.7 |
| Pump Out Septic System | 2.5 | 2.9 | 4.0 | 3.4 | 1.4 |
| Improve Physical Condition of Water Source | 0.5 | 1.4 | 0 | 0 | 0 |
| Shock-Chlorinate Water System | 5.1 | 13.0 | 0 | 3.4 | 0 |
| Obtain New Water Source | 1.5 | 0 | 4.0 | 0 | 2.7 |
| Use Bottled Water for Drinking/Cooking | 11.7 | 13.0 | 20.0 | 31.0 | 0 |
| Temporary Disinfection, such as Boiling Water | 0.5 | 0 | 0 | 3.4 | 0 |
| Purchase or Rent Water Treatment Equipment | 13.7 | 11.6 | 28.0 | 27.6 | 5.4 |
| Improve Existing Water Treatment Equipment | 7.1 | 11.6 | 4.0 | 13.8 | 1.4 |
| Take Other Measures to Eliminate/Reduce Contaminant(s) | 3.6 | 7.2 | 0 | 0 | 2.7 |
| Have Not Done Anything | 54.3 | 37.7 | 40.0 | 24.1 | 86.5 |
Participants were asked if the water analysis showed that their water was unsatisfactory for one or more of the following: bacteria, nitrate, sodium, iron, manganese, hardness, and pH. Responses were grouped in four categories: 1) households with potential health problems (positive bacteria test results and/or unsatisfactory levels of nitrate or sodium in their water samples), 2) households with unsatisfactory levels of nuisance contaminants (one or more of the following: iron, manganese, hardness, and pH), 3) households with potential health problems and unsatisfactory levels of nuisance contaminants, and 4) households with neither potential health problems nor unsatisfactory levels of nuisance contaminants.
The measures planned or already taken to improve household water as follow-up to the water quality analysis were generally in agreement with the water quality problems identified by the testing. Of the households with potential health problems only, and those with health problems in combination with unsatisfactory levels of nuisance contaminants, 66% had taken, or planned to take, at least one measure to improve their water supply. The measure taken by the greatest number of households in these two categories was use bottled water drinking/cooking.
Respondents were actually slightly less likely to address health-related problems than nuisance problems. Of the households with unsatisfactory levels of one or more nuisance contaminants only and those with nuisance problems in combination with potential health problems, 68% had taken, or planned to take, at least one measure to improve their water supply. Not unexpectedly, the group of households that reported the fewest folllow-up measures (14%) were the households with neither potential health problems nor unsatisfactory levels of nuisance contaminants.
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Water quality analysis, for many nuisance constituents, generally supported the participants' descriptions of their water supplies regarding such problems as staining, taste and odor, and appearance. The severity of these symptoms is confirmed by the high incidence of water treatment devices installed 24% of all households participating had one or more water treatment devices installed.
Considering the results for both the raw and tap water sample groups, and the influence of the water treatment devices in use, the major remaining household water quality problems in Accomack and Northampton Counties, existing from a nuisance standpoint, were iron/manganese and total dissolved solids. The major health-related concern was bacteria. Furthermore, elevated sodium concentrations may present a health risk to some adults in a number of cases. Twenty-two percent of the samples tested positive for total coliform and 2% were positive for E. coli bacteria. In these positive cases, participants were advised of ways to improve water supply conditions and were encouraged to pursue retesting for coliform bacteria.
Sixty-five percent of the households that reported having at least one water quality problem had taken, or planned to take, at least one measure to improve the quality of their water supply. Ten percent or more of all respondents had taken, or planned to take, one or more of the following actions: purchase or rent water treatment equipment, use bottled water for drinking/cooking, and contact a state agency for further assistance.
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Koebel, C.T., M.S. Cavell, and W.L. Morgan. 1993. The Virginia Housing Atlas: Housing Trends and Patterns to 1990. Blacksburg, Virginia: VPI&SU, Virginia Center for Housing Research.
Ross, B. B., J. E. Woodard, T. A. Dillaha, E. B. Orndorff, J. R. Hunnings, and K. M. Hanna. 1991. Evaluating Household Water Quality in Warren County, Virginia. Information Series 91-1 (Household Water Quality Series 1). Blacksburg, Virginia: VPI&SU, College of Agriculture and Life Sciences.
USEPA. 1979. Methods for Chemical Analysis of Water and Wastes. Report No. EPA 600/4-79-020. Washington, D.C.: U.S. Environmental Protection Agency.
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* The following examples (2) - (5) represent forms, reports, etc. used in the Accomack County Program only. Paperwork for Northampton County was similar, except for the information that was county-specific.
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