Annual Drinking Water Quality Report

TOWN OF BIG STONE GAP

INTRODUCTION

This Annual Drinking Water Quality Report for calendar year 2006 is designed to inform you about your drinking water quality. Our goal is to provide you with a safe and dependable supply of drinking water, and we want you to understand the efforts we make to protect your water supply. The quality of your drinking water must meet state and federal requirements administered by the Virginia Department of Health (VDH).

If you have questions about this report, please call 276-523-2968 and ask for Gary Hampton or Mark S. Hollyfield.

The Big Stone Gap Town Council meets at 7:30 PM on the second Tuesday of each month at 505 East 5^th St. South.

GENERAL INFORMATION

Drinking water, including bottled drinking water, may reasonably be expected to contain at least small amounts of some contaminants.  The presence of contaminants does not necessarily indicate that water poses a health risk. More information can be obtained by calling the Environmental Protection Agency's Safe Drinking Water Hotline (800-426-4791).

Some people may be more vulnerable to contaminants in drinking water than the general population. Immuno-compromised persons such as persons with cancer undergoing chemotherapy, persons who have undergone organ transplants, people with HIV/AIDS or other immune system disorders, some elderly, and infants can be particularly at risk from infections. These people should seek advice about drinking water from their health care providers. EPA/CDC guidelines on appropriate means to lessen the risk of infection by cryptosporidium and other microbiological contaminants are available from the Safe Drinking Water Hotline (800-426-4791). 

The sources of drinking water (both tap and bottled water) include rivers, lakes, streams, ponds, reservoirs, springs, and wells. As water travels over the surface of the land or through the ground, it dissolves naturally-occurring minerals and, in some cases, radioactive material, and can pick up substances resulting from the presence of animals or from human activity. Contaminants that may be present in source water include: (1) Microbial contaminants such as viruses and bacteria, which may come from sewage treatment plants, septic systems, agricultural livestock operations, and wildlife. (2) Inorganic contaminants, such as salts and metals, which can be naturally-occurring or result from urban stormwater runoff, industrial or domestic wastewater discharges, oil and gas production, mining, or farming. (3) Pesticides and herbicides, which may come from a variety of sources such as agriculture, urban stormwater runoff, and residential uses. (4) Organic chemical contaminants, including synthetic and volatile organic chemicals, which are byproducts of industrial processes and petroleum production, and can also come from gas stations, urban stormwater runoff, and septic systems. (5) Radioactive contaminants, which can be naturally-occurring or be the result of oil and gas production and mining activities. In order to insure that tap water is safe to drink, EPA prescribes regulations which limit the amount of certain contaminants in water provided by public water systems. Food and Drug Administration regulations establish limits for contaminants in bottled water which must provide the same protection for public health.

SOURCE  and TREATMENT OF YOUR DRINKING WATER

The source of your drinking water is surface water from Big Cherry Reservoir located in Wise County. The Virginia Department of Health and the Town of Big Stone Gap conducted a source water assessment of our system during 2002.  The Big Cherry Reservoir was determined to be of high susceptibility to contamination using the criteria developed by the state in its approved Source Water Assessment Program.  The assessment report consists of maps showing the source water assessment area, an inventory of known land use activities of concern, and documentation of any known contamination with the last 5 years.  The report is available by contacting Mark S. Hollyfield at the phone number given elsewhere in this drinking water quality report.

Treatment of the raw water consists of  coagulation, flocculation, sedimentation, filtration, stabilization, fluoridation,  and chlorination.  These processes work together to remove the physical, chemical, and biological contaminants to make the water safe for drinking. The Town of Big Stone Gap welcomes tours at the water plant. Please call the water plant at 276-523-2968 to arrange a tour.

DEFINITIONS

The Town of Big Stone Gap routinely monitors constituents in your drinking water according to Federal and State regulations.  Many thousands of tests are performed each year to insure the quality of your drinking water. The table on the next page shows the results of our monitoring for the period of January 1^st to December 31^st, 2006.  In the table and elsewhere in this report you will find many terms and abbreviations you might not be familiar with.  The following definitions are provided to help you better understand these terms:

Maximum Contaminant Level, or MCL -  the highest level of a contaminant that is allowed in drinking water.  MCL’s are set as close to the MCLGs as feasible using the best available treatment technology.

Maximum Contaminant Level Goal, or MCLG - the level of a contaminant in drinking water below which there is no known or expected risk to health.  MCLGs allow for a margin of safety.

Non-detects (ND) - lab analysis indicates that the contaminant is not present

Parts per million (ppm) or Milligrams per liter (mg/l) - one part per million corresponds to one minute in two years or a single penny in $10,000.

Parts per billion (ppb) or Micrograms per liter - one part per billion corresponds to one minute in 2,000 years, or a single penny in $10,000,000.

Picocuries per liter (pCi/L) - picocuries per liter is a measure of the radioactivity in water.

Action Level - the concentration of a contaminant which, if exceeded, triggers treatment or other requirements which a water system must follow.

Treatment Technique (TT) - a required process intended to reduce the level of a contaminant in drinking water.

Nephelometric Turbidity Unit (NTU) - nephelometric turbidity unit is a measure of the clarity, or cloudiness, of water. Turbidity in excess of 5 NTU is just noticeable to the average person.  Turbidity is monitored because it is a good indicator of the effectiveness of our filtration system.

Maximum Residual Disinfectant Level Goal (MRDLG) – the level of drinking water disinfectant below which there is no known or expected risk to health. MRDLGs do not reflect the benefits of the use of disinfectants to control microbial contaminants.

Maximum Residual Disinfectant Level (MRDL) – the highest level of a disinfectant allowed in drinking water. There is convincing evidence that addition of a disinfectant is necessary for control of microbial contaminants.

  Regulated Contaminants                                     WATER QUALITY RESULTS

Lead and Copper Contaminants

VIOLATION INFORMATION

The Town of Big Stone Gap exceeded the four quarter Primary Maximum Contaminant Level running annual average of 0.080 mg/L for Total Trihalomathanes (TTHM) contained in the Commonwealth of Virginia/State board of Health Waterworks Regulations during the first, second, and third quarter monitoring periods of 2006.  Some people who drink water containing trihalomethanes in excess of the MCL over many years could experience problems with their liver, kidneys, or central nervous systems, and may have an increased risk of getting cancer.  The corrective action taken by the Town of Big Stone Gap were to move the chlorination feed point to a different location in the treatment facility, began feeding sodium permanganate to the raw water source, and changed the retention time of the water in the storage tanks.  These corrective actions have reduced the TTHM concentrations. There were no other violations of maximum contaminant levels(MCL) or treatment techniques(TT).

 MCL’s are set at very stringent levels by the U.S. Environmental Protection Agency.  In developing the standards EPA assumes that the average adult drinks 2 liters of water each day throughout a 70-year life span.  EPA generally sets MCLs at levels that will result in no adverse health effects for some contaminants or a one-in-ten-thousand to one-in-a-million chance of having the described health effect for other contaminants. The water quality results in this report are from testing done in 2006.  Some constituents are analyzed multiple times each day at the water plant. For example, the water plant staff analyzed the filter effluent turbidity almost 16,000 times in 2006. Others, which do not vary or are not routinely detected are sampled annually. The state allows us to monitor for some contaminants less than once per year because the concentrations of these contaminants do not change frequently.  Water from the Big Stone Gap water treatment and distribution system is regularly analyzed for about one hundred different water quality parameters to insure your safety. We check for organics, inorganics, metals, radiological, pesticides, herbicides, and other constituents. In this report, data is from samples collected in 2006 and we have included only constituents which were detectable by laboratory analysis. Some of our data, though accurate, is more than one year old.