IOWA STATE UNIVERSITY of Science and Technology Agricultural and Biosystems Engineering Extension

Diagnosing and Solving Common Water-Quality Problems

Heavy rainfall during 1993 increased the potential for bacterial contamination of rural wells throughout the Midwest. As a result of heightened public awareness of water-quality problems, Extension offices and State and county health authorities continue to receive many requests for information regarding flood-related and non-flood-related water-quality problems. Charting Your Course Although much could be written about each water-quality problem, information presented here covers only the most basic concepts. A chart format has been used to help private well owners quickly identify symptoms, causes, and possible remedies for nine common water-quality problems. To deal successfully with water-quality problems you must know which contaminants are present. If you've already tested your water, you can turn directly to charts covering the contaminants you've identified to learn about possible remedies. If you have not already tested your water, use the chart columns headed Where Does it Come From, Symptoms & Impacts,and How Does it Get Into My Water Supply to determine if symptoms and conditions associated with a particular contaminant are similar to those you've observed. Follow up with testing to determine if this contaminant is present in your water supply. For further information on water sampling and testing ask your County Extension Office for a copy of ISU Extension Publication Pm-1335 Sampling Your Drinking Water. Other Sources of Information Additional references are listed at the end of each chart. Remember that local assistance is available through many county environmental health departments. County health sanitarians are trained to assist with water related problems, and are familiar with specific remedies that work best in light of local well construction methods, geology, and land use.

Water laboratories play an essential role in identifying and solving water related problems. You may contact a commercial lab for advice on water testing, or if your locality is not served by commercial lab facilities, call the University Hygienic Laboratory (UHL) at The University of lowa (319-3354500). The UHL offers excellent laboratory facilities and highly-trained staff members who can help interpret your water test results. The Health Engineering Section of the lowa Department of Public Health (IDPH) also offers consultation on a variety of health-related water problems. The IDPH also administers a program that regulates advertisement and sale of home water treatment units. For further information on selecting water treatment equipment, Contact IDPH (515-242-6340) for a copy of their consumer information pamphlet entitled Residential Water Treatment Systems. For the thousands of rural lowans using seriously-deteriorated wells, new well construction may be necessary to obtain the desired quantity and quality of water. For advice on local geology, the quality of water available at various depths, and recommended well construction techniques to minimize the likelihood of future contamination, contact the Geological Survey Bureau of the lowa Department of Natural Resources (IDNR) (319-335-1575). IDNR geologists have long taken the lead in conducting statewide studies of groundwater and have achieved a national reputation for their efforts to protect the quality of lowa's groundwater resources. Technical review was provided by: Nancy Hall, University of Iowa Hygienic Laboratory; Paul Van Dorpe, Iowa Department of Natural Resources Geological Survey Bureau; and Rita Gerge/y, Iowa Department of Public Health.

Other Sources of Information on Total and Fecal Coliform Bacteria:
ISU Extension Publication Pm-840 Good Wells for Safe , or ISU Extension Publication Pm-1329 Coping With Contaminated Wells
ISU Extension Publication Pm-899 Shock Chlorinating Small Water Systems
ISU Extension Quality Water video tape # 75704 Coliform Bacteria and viewers guide (AE-3060)
University of lowa Hygienic Laboratory Public Service Information,Well Water Quality and Home Treatment Systems

Where Does it Come From?	Symptoms and Impacts	What Levels are of Concern?	How Does it Get Into My Water Supply?	What Can I Do?
Iron bacteria occur naturally in soil, shallow groundwater, and in cool surface water. Iron bacteria may also be transported from one well to another on well contractors' tools.	Symptoms: Iron bacteria coat the interior of the well and water system with an insoluble reddish brown slime layer. Small particles of the bacterial slime layer may intermittently break loose and be flushed out of the system. If this occurs during laundering, light-colored clothing may exhibit flecks of reddish-brown stain. Impacts: If allowed to build up, iron bacteria can cause plugging of pump intakes, well screens, small water pipes, and nipple-type livestock waterers. Iron bacteria may also impart an unpleasant odor to drinking water. Note: Iron bacteria deposits look very much like mineral iron deposits. Microscopic examination is the most reliable way to determine if iron bacteria are present. See guidelines for sample collection in adjoining column.	Since iron bacteria appear to cause no significant health effects, the USEPA has not established drinking water standards for iron bacteria. Water laboratories simply report iron bacteria test results as present or absent. NOTE: Since iron bacteria adhere to the interior surfaces of the water system, special methods are required to collect samples for microscopic examination. The sample MUST include some residue scraped from the interior of the plumbing system. The most accessible location for sample collection is often a toilet water storage tank. Remove the tank lid and scrape reddish-colored residue from the walls below water line. Place residue in the sample bottle and fill the bottle with water to keep the residue wet.	Tools used in well construction or maintenance may pick up iron bacteria from soil and shallow groundwater and seed these organisms into new or reconstructed wells. To minimize the likelihood of spreading iron bacteria, ALL tools and construction materials should be disinfected before being used or installed in a well.	If plugging and staining are not severe, iron bacteria may be controlled with occasional shock chlorination of the well and water system. See Extension publication Pm-899 Shock Chlorinating Small Water Systems for further details. Note that it is nearly impossible to kill all of the iron bacteria in your water system, so they WILL grow back eventually. Be prepared to repeat the shock chlorination treatment from time to time. If iron bacterial-regrowth is rapid, and plugging or staining severe, repeated shock chlorination may become time consuming. Continuous application of low levels of chlorine (usually 1 mg/l or less of free available chlorine) may be less time consuming and more effective. An automatic liquid chlorine injector pump, or mechanical dispenser that drops chlorine pellets into the well, are commonly-used methods for continuous application of chlorine to control iron bacteria.

Other Sources of Information on Iron Bacteria:
ISU Extension Publication Pm-899 Shock Chlorinating Small Water Systems
ISU Extension Quality Water video tape # 75703 Red Waterand viewers guide (AE-3059)
University of lowa Hygienic Laboratory Public Service Information,Well Water Quality and Home Treatment Systems

Where Does it Come From?	Symptoms and Impacts	What Levels are of Concern?	How Does it Get Into My Water Supply?	What Can I Do?
1. Decay of naturally-occurring organic matter in soil; 2. Livestock manure; 3. Septic systems; 4. Excessive use of nitrogen fertilizers; 5. Nitrogen fixing crops (legumes such as soybeans).	Symptoms: Nitrate causes no readily-observed odors, flavor, or discoloration. Testing is the ONLY way to tell if high concentrations of nitrate are present in your drinking water. Nitrate testing at least once each year is recommended. Impacts: When consumed by infants (generally those less than 6 months old) in food, water, or formula, nitrate can cause a serious blood disorder known as infant methemoglobinemia or "blue baby" syndrome. While some studies have suggested a possible link between nitrate and cancer, the USEPA indicates that current data are insufficient to conclude that nitrate in drinking water increases the risk of cancer in humans.	To minimize the risk of infant methemoglobinemia, nitrate concentrations in drinking water should not exceed the U.S. Environmental Protection Agency maximum contaminant level (MCL). The current MCL for nitrate is: 1. 45 mg/l** if reported as nitrate (NO3); OR 2. 10 mg/l** if reported as nitrate-nitrogen (NO3-N); Note: As suggested above, laboratories may report nitrate two ways (as nitrate OR as nitrate-nitrogen). BE SURE TO READ your laboratory report carefully and compare the reported results with the correct form of the MCL. For livestock and poultry, recommended "safe" upper limits range from 100 to 440 mg/l (measured as nitrate), depending on species. Note that effects of nitrate in feed and water are additive. Both sources must be considered when evaluating a potential nitrate problem in animals.	Transported into well with surface water or shallow groundwater. NOTE: Although high levels of nitrate generaily originate from nitrogen sources above ground or in the topsoil, percolating rainfall dissolves nitrate and transports it deeper into the ground. Shallow aquifers and wells are more likely to be contaminated with nitrate than deeper ones.	For small quantities of drinking water, install a water treatment system that has beentested and proven capable of reliablyremoving nitrate from a private water supply (see consumer note below regarding treatment system performance data). Types of treatment equipment having potential to remove nitrate include distillation or reverse osmosis. For larger quantities of water, drill properly constructed well located away from obvious sources of nitrate. Contact lowa Department of Natural Resources Geological Survey Bureau (319-335-1575) for advice on appropriate well depth, location, and type of construction to avoid future nitrate problems. lowa law requires that treatment systems advertised as being capable of removing nitrate from drinking water must be tested according to state-approved procedures. A performance data sheet, summarizing the results of these tests, MUST be given to potential buyers or rentors PRIOR to completion of the sale or rental agreement. For further information on this important consumer protection law, contact the lowa Department of Public Health (515-242-6340 ).

Other sources of Information on Nitrate:
ISU Extension Publication Pm-840 Good Wells for Safe Water
ISU Extension Publication Pm-1329 Coping With Contaminated Wells
ISU Extension Quality Water video tape # 75705 Nitrateand viewers guide (AE-3061) )
University of lowa Hygienic Laboratory Public Service Information,Well Water Quality and Home Treatment Systems
**mg/l = milligrams per liter

Where Does it Come From?	Symptoms and Impacts	What Levels are of Concern?	How Does it Get Into My Water Supply?	What Can I Do?
1. Naturally occurring mineral in soil and rock; 2. Corrosion of iron pipes.	Symptoms: Red or yellowish colored water, stains on fixtures, stains on laundry. Two forms of iron are common. If water is continuously red or yellow colored as it flows from the tap, this indicates presence of oxidized iron. If water is clear, when first drawn from tap, and turns red or yellow after exposure to air, this is referred to as unoxidized or "clear water" iron. Impacts: Iron can plug pump intakes, water softeners, cartridge filters and pipes, and stain fixtures and clothing.	Since iron in drinking water appears to cause no significant effect on human health, USEPA has not established drinking water standards for iron. Less than 0.3 mg/l** is recommended to avoid most color and staining problems.	Two common ways for iron to enter water supplies: 1. Transported into well with the ground water; OR 2. Corrosion of iron pipe caused by chemical, biological, or electrical activity.	1. For low levels (5 mg/l** or less) of clearwater iron, a water softener is often effective. 2. For moderate levels (5-10 mg/l**) ) of clear water iron, or if any oxidized iron is present, use an "iron filter" (also commonly called an oxidizing filter). 3. For high levels of clear water iron and/or oxidized iron, chemical oxidation (using chlorine or other oxidizing chemical) followed by a sand filter, may be necessary.

Where Does it Come From?	Symptoms and Impacts	What Levels are of Concern?	How Does it Get Into My Water Supply?	What Can I Do?
Caused by naturally occurring calcium and magnesium in soil and rock.	Symptoms: Scale accumulation in hot water lines, water heaters, dishwashers, and tea kettles. Soap scum accumulation on shower walls or bath tubs. Impacts: Plugging of water lines, reduced life of water heaters, diffficulty keeping shower, bath, and appliance surfaces clean.	Since hard water appears to cause no significant effect on human health, USEPA has not established drinking water standards for hardness. More than 120 mg/l** of calcium carbonate hardness is generally considered to be "hard" water.	Transported into well with groundwater.	1. Ion exchange softener (for home, farm, or small public supplies). CAUTION: if high levels of iron are also present, this can cause a gradual plugging of ion exchange softeners. Be prepared to apply a resin bed cleaning agent to the softener brine tank occasionally to reduce build-up of iron inside the softener, or install an iron filter ahead of the softener to reduce the amount of iron that enters the softener. 2. Lime softening process (for moderate- or large-sized public supplies.

Other Sources of Information on Iron & Hard Water:
ISU Extension Quality Water video tape # 75703 Red Water and viewers guide (AE-3059)
ISU Extension Quality Water video tape # 75702 Hard Water and viewers guide (AE-3058)
University of lowa Hygienic Laboratory, Public Service Information,Well Water Quality and Home Treatment Systems
**mg/l = milligrams per liter

Where Does it Come From?	Symptoms and Impacts	What Levels are of Concern?	How Does it Get Into My Water Supply?	What Can I Do?
Naturally occurring in some soil and rock.	Symptoms: colorless, and odorless; no distinctive characteristics. Impacts: Concentrations exceeding 250 mg/l can have laxative effect on some humans and young livestock. Sulfate also contributes to scale accumulation in boilers and water heaters.	Less than 250 mg/l** to minimize laxative effect in humans or poultry. Sulfate concentrations less than 1000 mg/l have not generally been associated with animal health problems. Consult your veterinarian for recommendations specific to a particular species.	Transported into well with groundwater.	1. Reverse osmosis or distillation -- for treating small quantities of drinking water. 2. Anion exchange filtration (operates similar to water softener) --for large quantities of water (i.e., livestock operations, or public water supplies).

Where Does it Come From?	Symptoms and Impacts	What Levels are of Concern?	How Does it Get Into My Water Supply?	What Can I Do?
A naturally occurring gas. Commonly found in groundwater that also contains sulfate.	Symptoms: Musty or "rotten egg" odor; black deposits inside pipes. Impacts: Corrosion of metal pipes; undesirable odors in laundry and shower areas.	Odors may become noticeable at levels of 0.05 mg/l** or less. Laboratory testing for hydrogen sulfide in a water supply is generally unnecessary. If it is present, your nose will quickly let you know.	1. Generated by sulfate-reducing bacteria living in well or plumbing system. 2. Hydrogen sulfide production in the plumbing system can be accelerated by the magnesium corrosion control anode in new water heaters. (Increased hydrogen sulfide odor is often reported after installation of a new water heater.)	To prevent formation of hydrogen sulfide in water system: 1. Shock chlorinate to reduce the population of sulfate-reducing bacteria in well or plumbing system; OR 2. Continuously chlorinate to maintain low level (1 mg/l) of free available chlorine residual; OR 3. If new water heater has been installed recently, removal of magnesium corrosion control anode from heater may help reduce sulfide odor in hot water. Removal of the magnesium anode may shorten the life of the heater and invalidate its warranty (check with manufacturer). Replacement with a zinc or aluminum rod may retain some corrosion protection while reducing odors. To remove hydrogen sulfide from water use: 1. Activated carbon filter to adsorb very low levels of hydrogen sulfide; OR 2. Oxidizing filter (iron filter) may remove low levels; OR 3. Chemical oxidation (such as chlorination) followed by filtration.

Other Sources of Information on Sulfate and HydrogenSulfide:
ISU Extension Quality Water video tape # 75707 Sulfurand viewers guide (AE-3063)
University of lowa Hygienic Laboratory Public Service Information,Well Water Quality and Home Treatment Systems
**mg/l = milligrams per liter

Where Does it Come From?	Symptoms and Impacts	What Levels are of Concern?	How Does it Get Into My Water Supply?	What Can I Do?
1. Chemical spills; 2. Improper chemical storage or disposal; 3. Excessive use or misapplication of chemical.	Symptoms: Although some chemicals (particularly petroleum products) impart a noticeable odor or color to water, at the relatively low concentrations often found in well water, many chemicals are undetectable by sight or smell. Testing is the ONLY reliable way to determine if manmade chemicals are present in drinking water. Since the costs of testing for manmade chemicals can be quite high, consult the University Hygienic Laboratory or a reputable commercial laboratory about appropriate tests for your particular situation. Health Concern: While some chemicals are toxic at very low concentrations: others appear to cause no ill effects. Health impacts vary widely with the type of chemical and its concentration. To learn more about health effects and drinking water guidelines for specific chemicals, contact the lowa Department of Public Health (Des Moines, IA., 515-242-6340), or the U.S. EPA Safe Drinking Water Hotline (Washington, DC., 1-800-426-4791 available Monday - Friday 8:30 AM - 5:00 PM eastern standard time).	The US Environmental Protection Agency has established health advisories (HA's are recommended maximum levels) and/or maximum contaminant levels (MCL's are legally enforced water-quality standards for public water supplies) for 125 organic chemicals. Atrazine, the agricultural herbicide found most commonly well water currently has an MCL of 3 micrograms per liter (ug/l). Alachlor (trade name Lasso) currently has an MCL of 2 ug/L.	May enter water supply through accidental spillage or back-siphoning of chemical directly into a well, or by leaching through soil and into shallow aquifers.	1. If spilled directly into well, it may be possible to pump the well to purge the chemical. Contact the lowa Department of Natural Resources (515-2818693) for advice on spill cleanupbefore you begin. 2. Construct new well at different site or at greater depth. Consult lowa Department of Natural Resources Geological Survey Bureau (319-3351575) for recommendations on depth, location, and construction of new well. 3. Treat water to remove contaminant. Removal performance will depend greatly on the physical and chemical characteristics of the chemical being removed. Test your water to be sure which chemicals (if any) are present. Ask for written performance data clearly stating that the unit has been tested and shown to remove the chemical of particular concern to you. lowa law requires that treatment systems advertised as being capable of removing health related (those having an EPA Maximum Contaminant Level) manmade chemicals from drinking water must be tested according to state-approved procedures. A performance data sheet, summarizing the results of these tests, MUST be given to potential buyers or rentors PRIOR to completion of the sale or rental agreement. For further information on this important consumer protection law, contact the lowa Department of Public Health (515-242

Other Sources of information on Water Contaminated with Manmade Chemicals:
ISU Extension Quality Water video tape # 75706 Manmade Chemicals & viewers guide (AE-3062)

AEN -152 2/15/94 Agricultural Engineering Notes (AEN's) are informally-published information releases on topics of current concern to lowans.
Prepared by Dr. Tom Glanville, Department of Agricultural and Biosystems Engineering, lowa State University, Ames, lowa

and Justice for All

The lowa Cooperative Extension Service's programs and policies are consistent with pertinent federal and state laws and regulations on nondiscrimination regarding race, color, national origin, religion, sex, age, and handicap.

Where Does it Come From?	Symptoms and Impacts	What Levels are of Concern?	How Does it Get Into My Water Supply?	What Can I Do?
Coliforms are naturally occurring bacteria commonly found in topsoil, surface water, sewage, and animal wastes.	Symptoms: Total coliforms usually cause no readily observable odors, flavor, or discoloration. Testing is the ONLY reliable way to tell if total coliform bacteria are present. Private wells should be tested for total coliform bacteria at least once each year. Impacts: Testing for these organisms is an inexpensive and effective way to determine if drinking water is bacterially unsafe. If total coliform bacteria are present, this warns that a pathway exists through which contaminated surface water or groundwater enters the water supply. Although total coliforms themselves do not generally cause disease, if these bacteria can get into your water supply, so can disease-causing organisms, manmade chemicals, and other contaminants that may be hazardous to your health.	Bacterial reporting methods vary from lab to lab, making test results somewhat confusing. While some labs clearly indicate whether the test result is considered to be "safe" or "unsafe," others simply report the number of organisms detected, leaving the client "in the dark" as to the safety of the water. If your test report indicates: " < 2.2 MPN" (less than 2.2 most probable number); OR "< 1 CFU" (less than 1 colony forming unit); OR that coliforms were "absent;" then the water is bacterially safe.	Total coliform bacteria are carried into wells and water systems along with surface runoff or shallow groundwater. When water supply wells contain total coliforms, this signals that defects in the well (or plumbing system) have created a pathway that allows contaminated water to enter the water system. Typical well defects include: 1. Missing or damaged well cap; 2. Cracks, corrosion holes, or other joints or openings in the upper 20 feet of the well; 3. Seepage of contaminated water along the outside of the well casing; 4. Well is extremely shallow (less than 20 feet of watertight casing); 5. Nearby abandoned well that is NOT properly plugged. Caution: Improper sample collection can lead to sample contamination and erroneous coliform test results. If coliform test results indicate "unsafe" water, even though well and water system inspection reveals no obvious defects, retest before investing time and money on well or water system modifications.	1. Inspect water system for defects described in adjoining column. If well appears structurally sound, review sample collection procedure. If incorrect, resample using recommended procedures. 2. If well appears structurally sound and unsafe total coliform test occurred following recent well repair, contamination may be a result of inadequate disinfection of well or water system following repair. Shock chlorinate the well and water system and retest. 3. If well and plumbing system inspection reveals defects, repair defects, then shock chlorinate and retest for total coliform after chlorine has been purged from the system. 4. If well defects cannot be located, seek assistance from county health sanitarian or certified well contractor. Boil water or purchase bottled water for drinking until bacterial contamination is remedied. 5. Construct new well _ install a water treatment system that has been tested and proven capable of reliablydisinfecting a private water supply. (see consumer note below) lowa law requires that treatment systems advertised as being capable of disinfecting bacterially-contaminated water MUST be tested according to state-approved procedures. Furthermore, a performance data sheet summarizing the results of these tests MUST be given to potential buyers or rentors PRIOR to completion of the sale or rental agreement. For further information on this important consumer protection law, contact the lowa Department of Public Health (515-242-6340).