Table 3-2: Potential Sources of Groundwater Contaminants (Return to: Chapter 3 - Step 1 ; Chapter 3 - Step 4) or Use Your Browser's Back Arrow to Return to Document


Groundwater Contaminants1,2,3



Body Shops/Repair Shops

Waste oils; solvents; acids; paints; automotive wastes4; miscellaneous cutting oils.

Car Washes

Soaps; detergents; waxes; miscellaneous chemicals; hydrocarbons.  

Gas Stations

Oils; solvents; miscellaneous wastes.  

Boat Services/Repair/Refinishing

Diesel fuels; oil; septage from boat waste disposal area; wood preservative and treatment chemicals; paints; waxes; varnishes; automotive wastes4.  

Cement/Concrete Plants

Diesel fuels; solvents; oils; miscellaneous wastes.  

Chemical/Petroleum Processing/Storage

Hazardous chemicals; solvents; hydrocarbons; heavy metals; asphalt.  

Dry Cleaners

Solvents (perchloroethylene, petroleum solvents, Freon); spotting chemicals (trichloroethane, methylchloroform, ammonia, peroxides, hydrochloric acid, rust removers, amyl acetate).  

Electrical/Electronic Manufacturing

Cyanides; metal sludges; caustic (chromic acid); solvents; oils; alkalis; acids; paints and paint sludges; calcium fluoride sludges; methylene chloride; perchloroethylene; trichloroethane; acetone; methanol; toluene; PCBs.  

Fleet/Trucking/Bus Terminals

Waste oil; solvents; gasoline and diesel fuel from vehicles and storage tanks; fuel oil; other automotive wastes4.  

Food Processing

Nitrates; salts; phosphorus; miscellaneous food wastes; chlorine; ammonia; ethylene glycol.  

Funeral Services/Graveyards

Formaldehyde; wetting agents; fumigants; solvents; leachate; lawn and garden maintenance chemicals5.  

Furniture Repair/Manufacturing

Paints; solvents; degreasing and solvent recovery sludges; lacquers; sealants.  

Hardware/Lumber/Parts Stores

Hazardous chemical products in inventories; heating oil and fork lift fuel from storage tanks; wood-staining and treating products such as creosote; paints; thinners; lacquers; varnishes.  

Home Manufacturing

Solvents; paints; glues and other adhesives; waste insulation; lacquers; tars; sealants; epoxy wastes; miscellaneous chemical wastes.  

Junk/Scrap/Salvage Yards

Automotive wastes4; PCB contaminated wastes; any wastes from businesses6 and households7; oils; lead.  

Machine Shops

Solvents; metals; miscellaneous organics; sludges; oily metal shavings; lubricant and cutting oils; degreasers (tetrachloroethylene); metal marking fluids; mold-release agents.  

Medical/Vet Offices

X-ray developers and fixers8; infectious wastes; radiological wastes; biological wastes; disinfectants; asbestos; beryllium; dental acids; miscellaneous chemicals.  

Metal Plating/Finishing/Fabricating

Sodium and hydrogen cyanide; metallic salts; hydrochloric acid; sulfuric acid; chromic acid; boric acid; paint wastes; heavy metals; plating wastes; oils; solvents.  

Mines/Gravel Pits

Mine spills or tailings that often contain metals; acids; highly corrosive mineralized waters; metal sulfides; metals; acids; minerals sulfides; other hazardous and nonhazardous chemicals9.  

Office Buildings/Complexes

Building wastes6; lawn and garden maintenance chemicals5; gasoline; motor oil.  

Parking Lots/Malls (> 50 spaces) (H)

Hydrocarbons; heavy metals; building wastes6.  

Photo Processing/Printing

Biosludges; silver sludges; cyanides; miscellaneous sludges; solvents; inks; dyes; oils; photographic chemicals.  

Plastics/Synthetics Producers

Solvents; oils; miscellaneous organic and inorganics (phenols, resins); paint wastes; cyanides; acids; alkalis; wastewater treatment sludges; cellulose esters; surfacant; glycols; phenols; formaldehyde; peroxides; etc.  

Research Laboratories

X-ray developers and fixers8; infectious wastes; radiological wastes; biological wastes, disinfectants; asbestos; beryllium; solvents; infectious materials; drugs; disinfectants; (quaternary ammonia, hexachlorophene, peroxides, chlornexade, bleach); miscellaneous chemicals.  

RV/Mini Storage

Automobile wastes4; gasoline and diesel fuel from vehicles and storage tanks  

Wood Preserving/Treating

Wood preservatives: creosote, pentachlorophenol, arsenic; heavy metals.  

Wood/Pulp/Paper Processing and Mills

Metals; acids; minerals; sulfides; other hazardous and nonhazardous chemicals9; organic sludges; sodium hydroxide; chlorine; hypochlorite; chlorine dioxide; hydrogen peroxide; treated wood residue (copper quinolate, mercury, sodium bazide); methanol; paint sludges; solvents; creosote; coating and gluing wastes.  



Auction Lots/Boarding Stables

Livestock sewage wastes; nitrates; phosphates; coliform and noncoliform bacteria; giardia, viruses; total dissolved solids.  

Confined Animal Feeding Operations

Livestock sewage wastes; nitrates; phosphates; chloride; chemical sprays and dips for controlling insect, bacterial, viral and fungal pests on livestocks; coliform10 and noncoliform bacteria; viruses; giardia; total dissolved solids.  

Farm Machinery Repair

Automotive wastes4; welding wastes.  

Crops - Irrigated and Nonirrigated

Pesticides11; fertilizers12; nitrates; phosphates; potassium (can be worsened by over-watering).  

Lagoons/Liquid Wastes

Nitrates; Livestock sewage wastes; salts; pesticides11; fertilizers17; bacteria.  

Pesticide/Fertilizer/Petroleum Storage & Transfer Areas

Pesticides11; fertilizers12; petroleum residues.  

Rural Homesteads - Rural

Machine shops: Automotive wastes4; welding wastes; solvents; metals; subricants; sludges.  
    Septic systems: Septage; coliform10 and noncoliform bacteria; viruses; nitrates; heavy metals; synthetic detergents; cooking and motor oils; bleach; pesticides;5,13 paints; paint thinner; photographic chemicals; swimming pool chemi-cals;14 septic tank/cesspool cleaner chemicals;15 elevated levels of chloride, sulfate, calcium, magnesium, potassium, and phosphate.  



Airports (Maintenance/Fueling Areas)

Jet fuels; deicers; diesel fuel; chlorinated solvents; automotive wastes;4 heating oil; building wastes6.  

Apartments and Condominiums

Swimming pool maintenance chemicals14 ; pesticides for lawn and garden maintenance and cockroach, termite, ant, rodent, and other pest control5,13, wastes from on-site sewage treatment plants; household hazardous wastes.  

Camp Grounds/RV Parks

Septage; gasoline; diesel fuel from boats; pesticides for controlling mosquitoes, ants, ticks, gypsy moths, and other pests11,13; household hazardous wastes from recreational vehicles (RVs)7.  

Drinking Water Treatment Plants

Treatment chemicals; pesticides11.  

Fire Stations

General building wastes6; hydrocarbons from test burn areas.  

Golf Courses

Fertilizers12; herbicides11; pesticides for controlling mosquitoes, ticks, ants, gypsy moths, and other pests5.  


Household hazardous wastes7: Household cleaners; oven cleaners; drain cleaners; toilet cleaners; disinfectants; metal polishes; jewelry cleaners; shoe polishes; synthetic detergents; bleach; laundry soil and stain removers; spot removers and dry cleaning fluid; solvents; lye or caustic soda; household pesticides;13 photo chemical; paints; varnishes; stains; dyes; wood preservatives (creosote); paint and lacquer thinners; paint and varnish removers and deglossers; paint brush cleaners; floor and furniture strippers.  
  Mechanical repair and other maintenance products: Automotive wastes;4 waste oils; diesel fuel; kerosene; #2 heating oil; grease; degreasers for driveways and garages; metal degreasers; asphalt and roofing tar; tar removers; lubricants; rustproofers; car wash detergents; car waxes and polishes; rock salt; refrigerants.  
  Lawn/garden care: Fertilizers;11 herbicides and other pesticides used for lawn and garden maintenance5 (can be worsened by over-watering).  
  Swimming pools: Swimming pool maintenance chemicals14.  
  Urban runoff/storm water3: Gasoline; oil; other petroleum products; microbiological contaminants.  


Leachate; organic and inorganic chemical contaminants; waste from households7 and businesses6; nitrates; oils; metals; solvents; sludge.  

Motor Pools

Automotive wastes4: solvents; waste oils; hydrocarbons from storage tanks.  


Fertilizers12; herbicides5; insecticides11,13.  

Railroad Yards/Maintenance/Fueling Areas

Diesel fuel; herbicides for rights-of-way11; creosote from preserving wood ties; solvents; paints; waste oils.  


Machinery/vehicle serving wastes; gasoline and heating oil from storage tanks; general building wastes6; pesticides11,13.  

Septic Systems

Septage; coliform10 and noncoliform bacteria; viruses; nitrates; heavy metals; synthetic detergents; cooking and motor oils; bleach; pesticides5,13; paints; paint thinner; photographic chemicals; swimming pool chemicals14; septic tank/cesspool cleaner chemicals15; elevated levels of chloride, sulfate, calcium, magnesium, potassium, and phosphate; other household hazardous wastes7.  

Utility Stations/Maintenance Areas

PCBs from transformers and capacitors; oils; solvents; sludges; acid solution; metal plating solutions (chromium, nickel, cadmium); herbicides from utility rights-of-way.  

Waste Transfer/Recycling Stations

Residential and commercial solid waste residues.  


Municipal wastewater; sludge16; treatment chemicals17; nitrates; heavy metals; coliform10 and noncoliform bacteria; nonhazardous wastes16.  



Above Ground Storage Tanks

Heating oil; diesel fuel; gasoline; other chemicals.  

Construction/Demolition Areas (Plumbing, Heating, and Air Conditioning, Painting, Paper Hanging, Decorating, Drywall and Plastering, Acoustical Insulation, Carpentry, Flooring, Roofing, and Sheet Metal etc.)

Solvents; asbestos; paints; glues and other adhesives; waste insulation; lacquers; tars; sealants; epoxy waste; miscellaneous chemical wastes; explosives.  

Historic Gas Stations

Diesel fuel; gasoline; kerosene.  

Historic Waste Dumps/Landfills

Leachate; organic and inorganic chemicals; waste from households7; and businesses6; nitrates; oils; heavy metals; solvents.  

Injection Wells/Drywells/Sumps

Storm water runoff3; spilled liquids; used oils; antifreeze; gasoline; solvents; other petroleum products; pesticides11; and a wide variety of other substances.  

Managed Forests

Pesticides; fertilizers; total suspended solids.  

Military Installations

Wide variety of hazardous and nonhazardous wastes depending on the nature of the facility and operation3,9; diesel fuels; jet fuels; solvents; paints; waste oils; heavy metals; radioactive wastes; explosives.  

Surface Water - Stream/Lakes/Rivers

Directly related to surface water quality in the stream, lake, or river which is recharging groundwater.  

Transportation Corridors

Herbicides in highway right-of-way11,5; road salt (sodium and calcium chloride); road salt, anticaking additives (ferric ferrocyanide, sodium ferrocyanide); road salt anticorrosives (phosphate and chromate); automotive wastes4; fertilizers.  

Underground Storage Tanks

Diesel fuel; gasoline; heating oil; other chemical and petroleum products.  

Wells - Such as Water Supply Wells, Monitoring Wells, Unsealed or Abandoned Wells, and Test Holes

Storm water runoff3; solvents; nitrates; septic tanks; hydrocarbons; and a wide variety of other substances.  
1 In general, groundwater contamination stems from the misuse and improper disposal of liquid and solid wastes; the illegal dumping or abandonment of household, commercial, or industrial chemicals; the accidental spilling of chemicals from trucks, railways, aircraft, handling facilities, and storage tanks; or the improper siting, design, construction, operation, or maintenance of agricultural, residential, municipal, commercial, and industrial drinking water wells and liquid and solid waste disposal facilities. Contaminants also can stem from atmospheric pollutants, such as airborne sulfur and nitrogen compounds, which are created by smoke, flue dust, aerosols, and automobile emissions, fall as acid rain, and percolate through the soil. When the sources list in this table are used and managed properly, groundwater contamination is not likely to occur.

2 Contaminants can reach groundwater from activities occurring on the land surface, such as industrial waste storage; from sources below the land surface but above the water table, such as septic systems; from structures beneath the water table, such as wells; or from contaminated recharge water.

3 This table lists the most common wastes, but not all potential wastes. For example, it is not possible to list all potential contaminants contained in storm water runoff or from military installations.

4 Automobile wastes can include gasoline; antifreeze; automatic transmission fluid; battery acid; engine and radiator flushes; engine and metal degreasers; hydraulic (brake) fluid; and motor oils.

5 Common pesticides used for lawn and garden maintenance (i.e., weed killers, and mite, grub, and aphid controls) include such chemicals as 2,4-D; chlorpyrifos; diazinon; benomyl; captan; dicofol; and methoxychlor.

6 Common wastes from public and commercial buildings include automotive wastes; and residues from cleaning products that may contain chemicals such a xylenols, glycol esters, isopropanol, 1,1,1,-trichloroethane, sulfonates, chlorinated phenols, and cresols.

7 Household hazardous wastes are common household products which contain a wide variety of toxic or hazardous components (see also Appendix F: Household Waste Fact Sheet).

8 X-ray developers and fixers may contain reclaimable silver, glutaldehyde, hydroquinone, potassium bromide, sodium sulfite, sodium carbonate, thiosulfates, and potassium alum.

9 The Resource Conservation and Recovery Act (RCRA) defines a hazardous waste as a solid waste that may cause an increase in mortality or serious illness or pose a substantial threat to human health and the environment when improperly treated, stored, transported, disposed of, or otherwise managed. A waste is hazardous if it exhibits characteristics of ignitability, corrosivity, reactivity, and/or toxicity. Not covered by RCRA regulations are domestic sewage; irrigation waters or industrial discharges allowed by the Clean Water Act; certain nuclear and mining wastes; household wastes; agricultural wastes (excluding some pesticides); and small quantity hazardous wastes (i.e., less than 220 pounds per month) generated by businesses.

10 Coliform bacteria can indicate the presence of pathogenic (disease-causing) microorganisms that may be transmitted in human feces. Diseases such as typhoid fever, hepatitis, diarrhea, and dysentery can result from sewage contamination of water supplies.

11 Pesticides include herbicides, insecticides, rodenticides, fungicides and avicides. EPA has registered approximately 50,000 different pesticide products for use in the United States. Many are highly toxic and quite mobile in the subsurface. An EPA survey found that the most common pesticides found in drinking water wells were DCPA (dacthal) and atrazine, which EPA classifies as moderately toxic (class 3) and slightly toxic (class 4) materials, respectively.

12 The EPA National Pesticides Survey found that the use of fertilizers correlates to nitrate contamination of groundwater supplies.

13 Common household pesticides for controlling pests such as ants, termites, bees, wasps, flies, cockroaches, silverfish, mites, ticks, fleas, worms, rates, and mice can contain active ingredients include naphthalene, phosphorus, xylene, chloroform, heavy metals, chlorinated hydrocarbons, arsenic, strychnine, kerosene, nitrosamines, and dioxin.

14 Swimming pool chemicals can contain free and combined chlorine; bromine; iodine; mercury-based, copper-based, and quaternary algaecides; cyanuric acid; calcium or sodium hypochlorite; muriatic acid; sodium carbonate.

15 Septic tank/cesspool cleaners include synthetic organic chemicals such as 1,1,1,-trichloroethane, tetrachloroethylene, carbon tetrachlorine, and methylene chloride.

16 Muncipal wastewater treatment sludge can contain organic matter, nitrates; inorganic salts, heavy metals; coliform and noncoliform bacteria; and viruses.

17 Municipal wastewater treatment chemicals include calcium oxide; alum; activated alum, cabon, and silics; polymers; ion exhcange resins; sodium hydroxide; chlorine; ozone; and corrosion inhibitors.


Adapted from EPA (1993); Supplemented with Oregon DEQ database information.


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