Delaware Division of Public Health Office of Drinking Water A Guide to Help Interpret Your Drinking Water Results Where to get your water tested Private Well Test Kits The kits are $4 each and can be purchased at any of the locations listed below. The test kit contains two bottles: one to test for chemicals and one to test for bacteria. Instructions are included with each bottle and should be followed ' precisely. Drop off water samples at any of the same locations. Additional bottles are $2 each. New Castle County Limestone Professional Building 2055 Limestone Road, Suite 100 Wilmington, DE 19808 (302) 995-8650 Middletown Health Unit 214 N. Broad Street Middletown, DE 19709 (302) 378-5200 Kent County Thomas Collins Building 540 S. Dupont Highway, Suite 5 Dover, DE 19901 (302) 744-1220 Division of Public Health Laboratory 30 Sunnyside Road Smyrna, DE 19977 (302) 223-1520 Sussex County Georgetown State Service Center 544 S. Bedford Street Georgetown, DE 19947 (302) 856-5496 Did you know? • The Office of Drinking Water monitors approximately 520 public water systems throughout Delaware. • Delaware residents use approximately 91 million gallons of public water each day. • About 18% of Delaware residents own a private well in which the water quality is not regulated by either the federal or state government. • The Office of Drinking Water recommends that owners of private wells have their water tested annually for chemical and bacteriological contaminants. Guide to Understanding Your Drinking Water Results Parts per million (ppm) = milligrams per liter (mg/L) Regulated analyses: maximum contaminant level (MCL) value Analyte Description Unregulated analyses: secondary standard (SS) value Alkalinity Alkalinity is a measure of the There is no recommended level for alkalinity buffering capacity of water. Know the alkalinity of water when installing treatment for other water quality parameters such as pH. Chloride (Cl) Chloride may adversely affect the (SS) 250 ppm. Note: High chlorides may also indicate salt taste, odor or color of drinking water, water intrusion or a failing septic system. but does not pose any known health risk. At 250 ppm, water could taste foul. Fluoride (F) Fluoride can naturally occur in (MCL) 2.0 ppm Delaware’s optimum range for fluoride is groundwater. All municipalities in (0.8 – 1.2 ppm). Fluoride should not exceed 2.0 ppm. Delaware are required to add fluoride to the drinking water for added dental benefits. Hardness Calcium and magnesium are two minerals (SS) The degrees of hardness range from soft to hard: which make water hard. Water hardness < (less than) 60 ppm: soft is measured either in grains per 60-120 ppm: moderately hard gallon (gpg) or as calcium hardness > (greater than) 120 ppm: extremely hard in ppm. One grain is equal to 17 ppm. Iron (Fe) Iron is the earth’s fourth most (SS) 0.3 ppm Above this level, iron may abundant element and is found in cause staining in household appliances, fixtures nearly all water supplies. Iron may and laundry. At very low levels, treatment adversely affect the aesthetic may not be necessary. quality of drinking water by taste, odor or color. However, iron does not pose any known health effects. Nitrate (NO3) Nitrate occurs naturally in some (MCL) 10 ppm (Acute Contaminant) If the level ground water, as a result of is 10 ppm or less means that your drinking water fertilizer use or from a failing meets drinking water standards. septic system. Since nitrates reduce the oxygen carrying capacity in the blood, they are harmful to unborn children and infants less than six months of age. In infants, the lack of oxygen causes the skin to appear blue or gray, a condition known as Blue Baby Syndrome. Nitrite (NO2) Nitrites are not stable in drinking (MCL) 1 ppm (Acute Contaminant) If the level is water and can quickly change to 1 ppm or less means that your water meets drinking Nitrates (NO3). The sources are the water standards. same and they both can cause Blue Baby Syndrome. To protect against the risk of adverse effects, the United States Environmental Protection Agency (EPA) has set the drinking water standard at 1 ppm. pH pH is a numerical expression (SS) 6.5 – 8.5 (Range of where environmental indicating whether your water is and aesthetic benefits can be achieved) Scale acidic or basic. High pH levels are of 0–14, 0 = highly acidic; 7 = neutral; undesirable since they may give the 14 = highly basic water a bitter taste. Low pH levels may leach copper and lead from your metal pipes. Sodium (Na) The EPA suggests a guidance level (SS) < (less than) 20 ppm for salt-restricted diets for sodium of 20 ppm in drinking 200 ppm or less for unrestricted diets water for those on severely salt- restricted diets. A level of 200 ppm or less is suggested for unrestricted diets. Sulfate (SO4) Sulfates are a combination of sulfur (SS) 250 ppm Higher levels may cause diarrhea and oxygen that can be released into groundwater from soil or rock formations. For More Information Contact: Office of Drinking Water Blue Hen Corporate Center 655 Bay Road, Suite 203 Dover, DE 19901 PHONE: (302) 741-8630 FAX: (302) 741-8631 DELAWARE HEALTH AND SOCIAL SERVICES Division of Public Health Doc. Control No. 35-05-20/07/08/19