Introduction

Private well owners often seek water treatment devices to solve a number of common problems that can be felt, smelled, tasted, or seen. Some of these symptoms indicate a serious problem, while others do not represent a health risk. If you notice any of the symptoms listed in the following table, first have your water tested by a certified independent laboratory to verify the cause of the problem. Call your local Cooperative Extension office and ask for "Water Testing for Private Well Owners," SP-00-20 for information on well testing. Testing may also reveal contaminants that have no visible color, odor, or taste, and yet represent health or safety risks.

Once you have determined the source of a well water problem, you can then match appropriate water treatment methods to the problem by consulting the table.

Problem	Symptom	Cause	Treatment
Hard Water	Soap curd and scum in wash basins and bathtub, or white scaly deposits in pipes, water heater or appliances	Calcium and magnesium salts	Cation-exchange water softeners
Grittiness	Abrasive texture to water when washing, or residues in sink	Very fine sand particles or silt in the water that is able to pass through the well screen	Use a sand trap or ultrafiltration
Odors	Musty, earthy or woody smell Chlorine smell Gasoline or oil smell Rotten egg odor Detergent odor or foaming water Methane gas (caution required; gas is explosive and toxic) Phenol (chemical) odor	Usually harmless organic matter Excessive chlorination Possible leak in fuel oil tank or other underground tank leaking into water supply Dissolved hydrogen sulfide gas in water supply Presence of sulfate-reducing bacteria in water supply Action of magnesium rod in hot water heater in the presence of soft water Septic tank leaking into groundwater supply Naturally decaying organic material found in: Shallow water wells near swamps Housing areas built above or near old landfills Aquifers overlying oil fields Industrial waste seeping into groundwater	Activated carbon filter There is no practical residential treatment system available. It is essential to locate and remove underground source. Activated carbon filters can provide some treatment Manganese greensand filter will help with levels over 6 mg/L when pH is not lower than 6.7 Hydrogen sulfide levels over 6 mg/L require constant chlorination followed by de-chlorinating and filtering Constant chlorination followed by activated carbon filtration Remove magnesium rod from heater Eliminate source and shock-chlorinate well Activated carbon filter will adsorb a limited amount Residential/commercial aeration system and re-pump Activated-carbon filter will adsorb for a short time before filter capacity is exceeded
Pesticides	Sharp chemical odor in water	Leaching of applied pesticides into groundwater	Activated carbon filter will help for short time; continue to monitor the treated water
Taste	Salty or brackish Soda taste, slippery feel Metallic taste	High sodium content High total dissolved solids that are alkaline in nature Very low pH (3 to 5.5) High iron content (over 3 mg/L)	Deionize drinking water only with disposable mixed-bed (anion-cation) resins Reverse osmosis for drinking water only Install home distillation system There is no economical treatment for residences when sodium levels exceed 1800mg/L Use reverse osmosis to reduce levels. If the level of alkalinity is greater than 3.080 mg/L there is no economical treatment for the home Calcite-type filter (see acid water) See heading for iron/reddish under appearance category

For information on well testing, call your local Cooperative Extension office and ask for Water Testing for Private Well Owners

Appearance
Problem	Symptom	Cause	Treatment
Turbidity (cloudiness)	Silt, clay, or suspended particles in water	Silt or sand from well	Sand trap and/or new well screen
Acidic water	Green stains on fixtures and/or a blue-green tint to the water	Water high in carbon dioxide content (with a pH below 6.8) that reacts with brass and copper plumbing	Calcite filter to neutralize pH if above 5.5 Calcite/magnesia-oxide mix at a 5 to 1 ratio to correct very low pH Soda ash chemical feed followed by filtration
Black cast to water	Black stains on fixtures and laundry	Interaction of carbon dioxide or organics and manganese in the soil. Above 0.05 mg/L, manganese causes staining, and is usually found combined with iron	Chlorination followed by filtration Oxidizing filter Ozonation Water softener Oxidation with potassium permanganate
Reddish or discolored water (from iron)	Red-brown stains on sinks and other porcelain fixtures; water turns reddish brown during cooking or heating; stains on laundry Brownish cast that does not precipitate and drop out of the water Reddish color in water sample after standing 24 hours	Indicates more than 0.3 mg/L dissolved iron present. Water appears clear when first drawn from cold water tap Precipitated iron (water is discolored when drawn) Iron dissolved from old pipe with pH below 6.8 Iron dissolved from old pipe with pH below 6.8 Organic (bacterial) iron Colloidal iron	Water softener and minimum pH of 6 .7 (unaerated) will remove 0.5 mg/L of iron for every 17 mg/L of hardness. For iron levels over 10 mg/L, chlorination in a retention tank that allows for oxidation, followed by filtration/dechlorination In warmer climates, residential aerator and filtration will substantially reduce iron If pH is higher than 6.7, a manganese greensand filter will remove up to 10 mg/L of iron. If pH is higher than 6.8 and oxygen is 15 percent of the total iron content, try manganese-treated, nonhydrous aluminum silicate filter Downflow water softener with good backwash will remove up to 1 mg/L To remove more than that, use a calcite filter followed by downflow water softener Shock chlorinate well, and follow with constant chlorination and filtration. Chemical feed of potassium followed by permanganate and then filtration Constant chlorination followed by filtration with activated carbon to remove chlorine
Milky water	Water cloudy when drawn	Precipitated sludge that is created when water is heated High volume of air in water from poorly functioning pump Excessive coagulant-feed being carried through filter	Flush water heater from time to time Water will generally clear quickly after standing Reduce coagulant quantity being fed Service filters properly
Yellow water	Yellowish tint to water after softening and/or filtering	Tannins (humic acids) present from water passing through peaty soil or decaying vegetation	Anion-exchange Chlorination with full retention time followed by filtration to remove chlorine

A chemical odor may be an indication of industrial waste seeping into groundwater

Contaminants with no visible color, odor or taste
Problem	Symptom	Cause	Treatment
High chloride content in water	Blackening and pitting of stainless steel sinks and kitchen ute	Excessive salt content. Note that high-temperature drying concentrates chloride, accelerating corrosion	Use chloride-resistant metals Distillation Reverse osmosis
Fluoride	Yellowish or mottled teeth in children.	Fluoride above 2.0 mg/L in groundwater	Anion exchange Reduce concentration to 0.2 mg/L with activated alumina Reverse osmosis Distillation
Nitrates	Maximum level set by EPA is 10 mg/L; this level or above is dangerous for infants	Sources include nearby human or animal waste leaching into well, or heavy use of commercial fertilizers with nitrogen entering the groundwater	Find sources of wastes and take steps to protect wellhead Anion exchange regenerated with NaCl for water with less than 3 mg/L; verify treatment level via water quality analysis Reverse osmosis for drinking and cooking water will remove 65 percent of nitrate; try to limit original concentration to 25 mg/l as N Home distillation system for drinking/cooking water
Radioactive contaminants	The public health authority will post notices. Radium 226 above 5piC/L and Strontium-90 above 10piC/L are considered health risks.	Naturally occurring in deep wells from phosphate rock or radium-bearing rock strata; atmospheric fallout or other human related activities that produce nuclear waste Radon gas given off by decaying radium dissolved in water	Remove cationic radioactivity with cation-exchange water softener Treat with mixed bed deionizer for removal of anionic and cationic nuclides Reverse osmosis should remove 70 percent of nuclides Aeration by faucet aerator to dissipate dissolved radon
Heavy Metals (lead, zinc, copper and cadmium)	EPA has established maximum contaminant levels (MCLs) for each metal	Industrial waste pollution; corrosion products from plumbing caused by low pH waters	Reverse osmosis pH adjustment to prevent corrosion of water distribution system Water softener will remove cadmium, copper and zinc if operated properly Distillation
Arsenic	EPA maximum is 0.01 mg/L; health risks increase above this level	Natural groundwater contaminants in certain regions; industrial waste; herbicides and pesticides	Reverse osmosis will remove up to 90 percent Activated alumina Anion exchange Distillation
Barium	EPA maximum is 2 mg/L; health risks increase above this amount	Naturally occurring in certain geographic areas	Remove using cation-exchange Reverse osmosis Distillation
Boron	Inhibits normal plant growth; above 1 mg/L considered undesirable for human use	Naturally occurring in the southwest United States and other areas	Selective anion-exchange resin Reverse osmosis Activated carbon Distillation
Cyanide	No visible color, taste or odor; above 0.2 mg/L considered health risk	Industrial waste pollution from electroplating, steel and coking facilities	Continuous chlorination and activated-carbon filtration of metals after pH adjustment Anion exchange Reverse osmosis
Trichloroethylene(TCE)	Notice from Public Health Department	Waste degreasing and dry cleaning solutions entering surface or groundwater supplies	Series of activated-carbon filters and constant monitoring between units for breakthrough Aeration Boiling

This table has been adapted from:

Driscoll, F. 1986. Groundwater and Wells. Johnson Division, St. Paul, MN
EPA. 1991. Manual of Individual and Non-Public Water Supply Systems, Appendix E: Identification by Human Senses. EPA 570/9-91-004.
Wagenet, L, K. Mancl and M. Sailus. 1995. Home Water Treatment. Northeast Regional Agricultural Engineering Service, Cooperative Extension, Ithaca, N. Y. NRAES-48.

Donaldson, S., Walker, M., and Courtois, D. 2000, Matching Drinking Water Quality Problems to Treatment Methods, Extension | University of Nevada, Reno, SP-00-19

Learn more about the author(s)

Mark Walker

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Matching Drinking Water Quality Problems to Treatment Methods

Introduction

Once you have determined the source of a well water problem, you can then match appropriate water treatment methods to the problem by consulting the table.

Problem	Symptom	Cause	Treatment
Hard Water	Soap curd and scum in wash basins and bathtub, or white scaly deposits in pipes, water heater or appliances	Calcium and magnesium salts	Cation-exchange water softeners
Grittiness	Abrasive texture to water when washing, or residues in sink	Very fine sand particles or silt in the water that is able to pass through the well screen	Use a sand trap or ultrafiltration
Odors	Musty, earthy or woody smell Chlorine smell Gasoline or oil smell Rotten egg odor Detergent odor or foaming water Methane gas (caution required; gas is explosive and toxic) Phenol (chemical) odor	Usually harmless organic matter Excessive chlorination Possible leak in fuel oil tank or other underground tank leaking into water supply Dissolved hydrogen sulfide gas in water supply Presence of sulfate-reducing bacteria in water supply Action of magnesium rod in hot water heater in the presence of soft water Septic tank leaking into groundwater supply Naturally decaying organic material found in: Shallow water wells near swamps Housing areas built above or near old landfills Aquifers overlying oil fields Industrial waste seeping into groundwater	Activated carbon filter There is no practical residential treatment system available. It is essential to locate and remove underground source. Activated carbon filters can provide some treatment Manganese greensand filter will help with levels over 6 mg/L when pH is not lower than 6.7 Hydrogen sulfide levels over 6 mg/L require constant chlorination followed by de-chlorinating and filtering Constant chlorination followed by activated carbon filtration Remove magnesium rod from heater Eliminate source and shock-chlorinate well Activated carbon filter will adsorb a limited amount Residential/commercial aeration system and re-pump Activated-carbon filter will adsorb for a short time before filter capacity is exceeded
Pesticides	Sharp chemical odor in water	Leaching of applied pesticides into groundwater	Activated carbon filter will help for short time; continue to monitor the treated water
Taste	Salty or brackish Soda taste, slippery feel Metallic taste	High sodium content High total dissolved solids that are alkaline in nature Very low pH (3 to 5.5) High iron content (over 3 mg/L)	Deionize drinking water only with disposable mixed-bed (anion-cation) resins Reverse osmosis for drinking water only Install home distillation system There is no economical treatment for residences when sodium levels exceed 1800mg/L Use reverse osmosis to reduce levels. If the level of alkalinity is greater than 3.080 mg/L there is no economical treatment for the home Calcite-type filter (see acid water) See heading for iron/reddish under appearance category

For information on well testing, call your local Cooperative Extension office and ask for Water Testing for Private Well Owners

Appearance
Problem	Symptom	Cause	Treatment
Turbidity (cloudiness)	Silt, clay, or suspended particles in water	Silt or sand from well	Sand trap and/or new well screen
Acidic water	Green stains on fixtures and/or a blue-green tint to the water	Water high in carbon dioxide content (with a pH below 6.8) that reacts with brass and copper plumbing	Calcite filter to neutralize pH if above 5.5 Calcite/magnesia-oxide mix at a 5 to 1 ratio to correct very low pH Soda ash chemical feed followed by filtration
Black cast to water	Black stains on fixtures and laundry	Interaction of carbon dioxide or organics and manganese in the soil. Above 0.05 mg/L, manganese causes staining, and is usually found combined with iron	Chlorination followed by filtration Oxidizing filter Ozonation Water softener Oxidation with potassium permanganate
Reddish or discolored water (from iron)	Red-brown stains on sinks and other porcelain fixtures; water turns reddish brown during cooking or heating; stains on laundry Brownish cast that does not precipitate and drop out of the water Reddish color in water sample after standing 24 hours	Indicates more than 0.3 mg/L dissolved iron present. Water appears clear when first drawn from cold water tap Precipitated iron (water is discolored when drawn) Iron dissolved from old pipe with pH below 6.8 Iron dissolved from old pipe with pH below 6.8 Organic (bacterial) iron Colloidal iron	Water softener and minimum pH of 6 .7 (unaerated) will remove 0.5 mg/L of iron for every 17 mg/L of hardness. For iron levels over 10 mg/L, chlorination in a retention tank that allows for oxidation, followed by filtration/dechlorination In warmer climates, residential aerator and filtration will substantially reduce iron If pH is higher than 6.7, a manganese greensand filter will remove up to 10 mg/L of iron. If pH is higher than 6.8 and oxygen is 15 percent of the total iron content, try manganese-treated, nonhydrous aluminum silicate filter Downflow water softener with good backwash will remove up to 1 mg/L To remove more than that, use a calcite filter followed by downflow water softener Shock chlorinate well, and follow with constant chlorination and filtration. Chemical feed of potassium followed by permanganate and then filtration Constant chlorination followed by filtration with activated carbon to remove chlorine
Milky water	Water cloudy when drawn	Precipitated sludge that is created when water is heated High volume of air in water from poorly functioning pump Excessive coagulant-feed being carried through filter	Flush water heater from time to time Water will generally clear quickly after standing Reduce coagulant quantity being fed Service filters properly
Yellow water	Yellowish tint to water after softening and/or filtering	Tannins (humic acids) present from water passing through peaty soil or decaying vegetation	Anion-exchange Chlorination with full retention time followed by filtration to remove chlorine

A chemical odor may be an indication of industrial waste seeping into groundwater

Contaminants with no visible color, odor or taste
Problem	Symptom	Cause	Treatment
High chloride content in water	Blackening and pitting of stainless steel sinks and kitchen ute	Excessive salt content. Note that high-temperature drying concentrates chloride, accelerating corrosion	Use chloride-resistant metals Distillation Reverse osmosis
Fluoride	Yellowish or mottled teeth in children.	Fluoride above 2.0 mg/L in groundwater	Anion exchange Reduce concentration to 0.2 mg/L with activated alumina Reverse osmosis Distillation
Nitrates	Maximum level set by EPA is 10 mg/L; this level or above is dangerous for infants	Sources include nearby human or animal waste leaching into well, or heavy use of commercial fertilizers with nitrogen entering the groundwater	Find sources of wastes and take steps to protect wellhead Anion exchange regenerated with NaCl for water with less than 3 mg/L; verify treatment level via water quality analysis Reverse osmosis for drinking and cooking water will remove 65 percent of nitrate; try to limit original concentration to 25 mg/l as N Home distillation system for drinking/cooking water
Radioactive contaminants	The public health authority will post notices. Radium 226 above 5piC/L and Strontium-90 above 10piC/L are considered health risks.	Naturally occurring in deep wells from phosphate rock or radium-bearing rock strata; atmospheric fallout or other human related activities that produce nuclear waste Radon gas given off by decaying radium dissolved in water	Remove cationic radioactivity with cation-exchange water softener Treat with mixed bed deionizer for removal of anionic and cationic nuclides Reverse osmosis should remove 70 percent of nuclides Aeration by faucet aerator to dissipate dissolved radon
Heavy Metals (lead, zinc, copper and cadmium)	EPA has established maximum contaminant levels (MCLs) for each metal	Industrial waste pollution; corrosion products from plumbing caused by low pH waters	Reverse osmosis pH adjustment to prevent corrosion of water distribution system Water softener will remove cadmium, copper and zinc if operated properly Distillation
Arsenic	EPA maximum is 0.01 mg/L; health risks increase above this level	Natural groundwater contaminants in certain regions; industrial waste; herbicides and pesticides	Reverse osmosis will remove up to 90 percent Activated alumina Anion exchange Distillation
Barium	EPA maximum is 2 mg/L; health risks increase above this amount	Naturally occurring in certain geographic areas	Remove using cation-exchange Reverse osmosis Distillation
Boron	Inhibits normal plant growth; above 1 mg/L considered undesirable for human use	Naturally occurring in the southwest United States and other areas	Selective anion-exchange resin Reverse osmosis Activated carbon Distillation
Cyanide	No visible color, taste or odor; above 0.2 mg/L considered health risk	Industrial waste pollution from electroplating, steel and coking facilities	Continuous chlorination and activated-carbon filtration of metals after pH adjustment Anion exchange Reverse osmosis
Trichloroethylene(TCE)	Notice from Public Health Department	Waste degreasing and dry cleaning solutions entering surface or groundwater supplies	Series of activated-carbon filters and constant monitoring between units for breakthrough Aeration Boiling

This table has been adapted from:

Driscoll, F. 1986. Groundwater and Wells. Johnson Division, St. Paul, MN
EPA. 1991. Manual of Individual and Non-Public Water Supply Systems, Appendix E: Identification by Human Senses. EPA 570/9-91-004.
Wagenet, L, K. Mancl and M. Sailus. 1995. Home Water Treatment. Northeast Regional Agricultural Engineering Service, Cooperative Extension, Ithaca, N. Y. NRAES-48.

Published by: Donaldson, S., Walker, M., and Courtois, D., 2000, Matching Drinking Water Quality Problems to Treatment Methods, Extension | University of Nevada, Reno, SP-00-19