-a series of SIX VIDEOS about safe and effective water systems.

Tape #4

Nitrate

This VIEWER REFERENCE GUIDEis yours to keep!
DO NOT RETURN ITwhen you return the tape.

MRC Catalog #75705

Why should I be concerned about nitrate?

It is dangerous to infants-especially those 6 months of age or younger.
If water contains nitrate in excess of drinking water standards,DO NOT use it for infant drinking water or for preparation of infant formula.

Private wells that contain high levels of nitrate may also be vulnerable to other kinds of contaminants.

A recent study of private wells in lowa showed that about 18% contain nitrate in excess of drinking water standards.

What causes nitrate to occur in our water?

Low levels occur naturally in rainfall, streams, and groundwater.

High levels are usually caused by concentrated sources of nitrogen such as animal feedlots, septic systems, or heavily fertilized cropland.

What IS the drinking water standard for nitrate?

Someone told me it's 45 milligrams per liter.
Someone else said it's 10 milligrams per liter.
WHICH IS CORRECT?

Both are correct.
There are two ways that laboratories can report nitrate test results:
-as nitrate: abbreviated on some laboratory reports as NO3
-or as nitrate-nitrogen: abbreviated on some laboratory reports as NO3-N

If your nitrate test results are reported as nitrate, the correct standard to compare them with is 45 milligrams per liter (mg/l).
If your nitrate test results are reported as nitrate-nitrogen,the standard to compare them with is 10 milligrams per liter (mg/l).

These two standards are equivalent: but to interpret the safety ofyour water correctly, you MUST read your test results carefully(to see which way they are reported),and compare them with the matching standard.

If nitrate levels are too high, what can I do?

Find another water source.
Use bottled water.
Hook up to a regional water supply.
Drill a new well.

Treat the water to lower the level of nitrate to the range considered "safe" for human consumption.

If I decide to invest in a new well, how can I minimize the risks of its having nitrate problems?

Locate the new well away from concentrated sources of nitrogen, such as feedlots, septic systems, and fertilizer storage areas.
Consult your county environmental health officer about recommended well location and depth.

Consult with your well driller, and the Geological Survey Bureau of the lowa Department of Natural Resources (319-0335-1575) regarding suggested well depths in your locale.
Deeper aquifers are less vulnerable to nitrate contamination than shallow ones.

Construct the new well properly, following state and local regulations,and be sure to properly plug the old well.

Get publications Pm-840, Good Wells for Safe Water, Pm-1329,Coping with Contaminated Wells, and Pm-1328, Plugging Abandoned Wells from your county Extension office.

What types of water treatment equipment can remove nitrate?

Distillation
Can remove nearly 100% of nitrate.
Energy intensive-releases heat to surrounding environment.
Most stills sold for home use have limited capacity: 5 to 10 gallons per day-enough for cooking and drinking.
Mineral scale will build up inside the boiling vessel. Periodic scale removal will be necessary.

CAUTION!

Distillation is a two-step process!

1. Water is boiled to produce steam.
2. This steam is cooled and condensed to form purified water.

Boiling alone will NOT remove nitrate.

Reverse Osmosis

Water passes through a special membrane which screens out most (but not all) of the nitrate and minerals.
When purchasing RO equipment, be sure to ask how much nitrate each brand and model can remove. This will vary; some RO units can remove 90% or more of the nitrate. Like distillation, most RO units sold for home use have limited capacity-5 to 10 gallons per day-enough for drinking and cooking.

Anion exchange
Operates much like a water softener. Water passes through a resin-filled tank which absorbs nitrate; resin must be regenerated periodically to maintain nitrate removal capacity.
Anion exchange is likely to have lower operating costs than distillation or reverse osmosis. This makes it well-suited for treating largequantities of water. Iron removal and water softening may be necessary to prevent the resin from getting fouled by iron or other minerals.

How can I tell if performance claims made for nitrate removal equipment are realistic?

Iowa law requires:
Water treatment devices advertised to remove health-related contaminants must be tested according to state-approved procedures.
Seller must present a performance data sheet (which shows these test results) to prospective customers beforeselling or renting equipment advertised to remove nitrate (or any other health-related contaminant).

-other sources of information-

Your local county or community environmental/health sanitarian

Iowa Department of Public Health, Lucas State Office Building, Des Moines, IA 50319-0075 (515 242-6340)

University of lowa Hygienic Laboratory. Oakdale Hall, lowa City, IA 52242 (319-335-4500)

Geological Survey Bureau Iowa Department of Natural Resources, 123 North Capitol, lowa City, IA 52242 '319-335-1575)

National Sanitation Foundation, 3475 Plymouth Rd., P.O. Box 1468, Ann Arbor, Ml 48106 (313-769 8010)

Water Quality Association, 4151 Naperville Rd., Lisle, IL 60532 (708-505-0160)

This material is based upon work supported by the U.S. Department of Agriculture,

Extension Services under project number 89-EWQI-1-9108

Ames, lowa 50011

AE 3061 July 1991

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