Water Systems for Small Communities

A Puzzle Guide for Local Officials
Bulletin 910

Water System Customers

Tony Nye, County Extension Agent, Ohio State University Extension
Karen Mancl, Professor Food, Agricultural and Biological Engineering, The Ohio State University

Water that is safe to drink and pleasant to use is the expectation of people living and traveling in the United States. Whether in a small town, a big city, or even a rural restaurant, people drink the water worry free.

Safe to Drink

Water systems are expected to deliver water to their customers that is safe to drink. Drinking water should not cause disease or result in acute or chronic toxicity. To ensure safe drinking water, the U.S. Congress directed the U.S. Environmental Protection Agency to establish maximum contaminant levels called primary drinking water standards. These maximum contaminant levels establish a "ceiling" that all water systems must meet and strive to always stay below. The purpose of the primary drinking water standards are to protect the public health.

Primary drinking water standards fall into five categories.

1. Pathogens cause disease. Bacteria, viruses, and parasites are tested for and controlled throughout a water system. Cloudy water, measured as turbidity, can contain bacteria. Therefore, the turbidity of drinking water must be monitored and reduced to minimize the threat of waterborne disease.
2. Some minerals and metals can be toxic at high enough levels in drinking water. Metals, like lead, and minerals, like nitrate, must be monitored for and kept below maximum contaminant levels.
3. Some organic compounds can be toxic if present in drinking water at high enough levels. Chemical solvents that may be used as degreaser and in dry cleaning, fuels like gasoline and fuel oil, and pesticides used on lawns, gardens, and farms can sometimes impact water supplies.
4. Radionuclides are considered toxins if in drinking water. Primary drinking water standards have been set for a range of radioactive materials.
5. Disinfection byproducts are toxins that can form in drinking water during the water treatment process. Water systems must monitor for and make adjustments to their treatment process to control disinfection byproducts.

Maximum contaminant levels for drinking water are constantly reviewed and updated as new research is considered. To obtain the latest primary drinking water standards check the US EPA web site (www.epa.gov/ogwdw/regs).

Pleasant to Use

Water that is safe to drink may not always be pleasant to use. Secondary drinking water standards are recommended to protect the public welfare. These aesthetic contaminants are listed in Table 1.

Table 1. Secondary Drinking Water Standards

Contaminant	Standard	Symptoms
Chloride	250 mg/l	Salty taste, corrodes pipes, blackens stainless steel
Copper	1.3 mg/l	Bitter or metallic taste, blue-green stains
Fluoride	2 mg/l	Brownish discoloration of teeth
Iron	0.3 mg/l	Bitter or metallic taste, brown-orange stains, iron bacteria, rusty sediment
Manganese	0.05 mg/l	Bitter or metallic taste, black stains
Sulfate	250 mg/l	Bitter taste, scaly deposits, laxative effects
Total Dissolved Solids (TDS)	500 mg/l	Salty or bitter taste, scaly deposits
Zinc	5 mg/l	Metallic taste
Color	15 color units	Visible tint
Corrosivity	noncorrosive	Pitted or leaking pipes, metallic taste, staining
Detergents	0.5 mg/l	Soapy taste, frothy, cloudy
Odor	3 threshold odor number	"rotten-egg," septic, musty, or chemical smell
pH	above 6.5	Bitter or metallic taste, pitting of pipes
	below 8.5	Soda taste, slippery feel, scaly deposits

Secondary drinking water standards are advisory. However, in Ohio, community water systems must remove high levels of iron and manganese.

Hard Water

Another water quality concern for water system customers is hard water. No standards have been set for water hardness, but water systems may choose to treat water to reduce hardness to minimize customer complaints. Guidelines for judging water hardness are listed in Table 2.

Table 2. Guidelines for Water Hardness

Concentration (Grains per gallon)	Level of Hardness
below 1.0	Very soft
1.0 to 3.5	Soft
3.5 to 7.5	Moderately hard
7.5 to 10.5	Hard
10.5 and above	Very hard