sw-103.pa

1991

Cooperative Extension

College of Agricultural Sciences

Agricultural and Biological Engineering

University Of Pennsylvania



HOW TO INTERPRET A WATER ANALYSIS REPORT



Paul D. Robillard, Assistant Professor of Agricultural Engineering
William E. Sharpe, Professor of Forest Hydrology
Kelli S. Martin, Sr. Research Technologist of Agricultural
Engineering


Whether your water causes illness, stains on plumbing, scaly deposits, or a bad taste, a water analysis identifies the problem and enables you to make knowledceable decisions about water treatment. What is the significance of the parameters listed in the water.test report? This fact sheet outlines some of the major parameters you may see on the analysis and assists you in understanding the report.

Features of a Sample Report

Once the lab has completed testing your water, you will receive a report that looks similar to Figure 1. It will contain a list of contaminants tested, the concentrations, and, in some cases, highlight any problem contaminants. An important feature of the report is the units used to measure the contaminant level in your water. Milligrams per liter (mg/1) of water are used for substances like metals and nitrates. A milligram per liter is also equal to one part per million (ppm)-that is one part contaminant to one million parts water. About 0.03 of a teaspoon of sugar dissolved in a bathtub of water is an approximation of one ppm. For toxic substances or other concentrations, the units used are even smaller. In these cases, parts per billion (ppb) are used. Another unit found on some test reports is that used to measure radon-picocurries per liter. Some values like pH, hardness, conductance, and turbidity are reported in units specific to the test.

ANALYTICAL LABORATORY REPORT

Client: Client's name                            Collected by: KM

Project: Analytical Laboratory Services          Project Number: CLOO0001

Date Collected: 08/28/90                         Time Collected: 7:35 am

Sample Identification: Kitchen Tap               Lab Number: 0 1 000

Analysis                         Results                    Units

----------------------------------------------------------------------
Total Coliform Bacteria             50                      #/looml

Nitrate-Nitrogen                  4.55                       mg/1

pH                                7.50                       units

Iron                              0.55                       mg/1

Hardness as CaCo3                  280                       mg/1

Sulfate Sulfur                    32.0                       mg/l

Chloride                          25.4                       mg/l

Specific Conductance               344                       umhos/cc

On the basis of the above test result(s), this water sample DOES NOT
MEET PADER drinking water standards

The following notes apply to this sample:

The Total Coliform Bacteria exceeded the max. lev. of 1 colony/100mi.
The Iron level exceeded the limit of 0.3 mg/1.

                               Submitted by:------------------
                                            Laboratory Manager

Figure 1. A sample water analysis report

In addition to the test results, a lab may make notes on any contaminants that exceeded the PADER drinking water standards. For example, in Figure I the lab noted that total coliform bacteria and iron both exceeded the standards. Sometimes the lab will send additional information about the problem contaminants.

Retain your copy of the report as a record of the quality of your water supply.If polluting activities such as mining occur in your area, you may need a record of past water quality to prove that your supply has been damaged.

Water test parameters

Generally, you will know beforehand which parameters are being tested. Perhaps, you had a one-time contamination incident or someone became ill after ingesting the water. Or maybe is simply a routine test to monitor any changes in your supply. Whatever the case, it is important to know what action to take if the test reveals a problem. Are the highlighted contaminants at levels where health is at risk? Is the contaminan an indicator that other water quality contaminan may be in the supply? Or is the contaminant simply a nuisance that stains your plumbing or causes odors?

The following tables provide a general guideline to water ualit arameters that may appear on your water analysis report. The parameters are divided into three categories: health risk parameters, general indicators, and nuisance parameters. These guidelines are by no means exhaustive. However, they will provide you with acceptable limits and some information about symptoms, sources of the problem and effects. To find out more about how to treat the water or eliminate the contaminant at the source, see related fact sheets listed on the Soil and Water Fact Sheet Listing. See the end of this publication for more details

Health Risk Parameters. The parameters in Table I are some commons ones that have known health effects. The table lists acceptable limits, potential health effects, and possible uses and sources of the contaminant.

Table 1: Standards, symptoms, and potential health effects of regulated contaminants

-------------------------------------------------------------------------------
Contaminant      Acceptable     Sources/Uses          Potential Health    
                 Limit                                   Effects at
                                                         High Concentrations
-------------------------------------------------------------------------------
Atrazine         3 ppb          Used as a herbicide;   Heart and liver damage
                                surface or groundwater   
                                contamination from
                                agricultural runoff 
                                or leaching.
-------------------------------------------------------------------------------
Benzene          5 ppb          Gasoline additive;     Blood disorders like
                                usually from           aplasticaremia; 
                                accidental oil spills, immune system           
                                industrial             depression; acute   
                                uses, or landfills.    exposure affects
                                                       central nervous system
                                                       causing dizziness, 
                                                       headaches;
                                                       long term exposure 
                                                       increases
                                                       cancer risks.
-------------------------------------------------------------------------------
Fluorides       (F4.0 mg/l     Additive in treatment   Mottling of teeth and 
                               process also used       bones.
                               in manufacturing
                               processes and 
                               insecticides.
-------------------------------------------------------------------------------
Lead*
-------------------------------------------------------------------------------
at tap          0.01 mg/1      Used in batteries;      Nervous disorders 
                               lead gasolines          and mental
                               and pipe solder; may be impairment, especially 
                               leached                 in fetuses
                               from brass              and infants; kidney 
                               faucets, lead           damage;
                               caulking, lead          blood disorders and
                               pipes, and lead         hypertension; 
                               soldered joints.                 
                               low birth weights.
-------------------------------------------------------------------------------
at source       0.005 mg/l
-------------------------------------------------------------------------------
Nitrates(NO3)   10 mg/1        Soil by-product of      Methemoglobinemia 
                (nitrate-N) 45 agricultural            (blue baby
                mg/l (nitrate) fertilization;          disease) in infants 
                               human and animal        (birth-6
                               waste leaching          months); Low health 
                               to groundwater.         threat to  
                                                       children and adults.
-------------------------------------------------------------------------------
Radon          300 pCi/l**     Naturally occurring     Breathing gas 
                               gas formed              increases chances
                               from uranium decay;     of lung cancer; 
                               can seep                may increase risk
                               intowell water from     of stomach, colon 
                               surrounding             and bladder
                               rocks and be released   cancers.
                               in the air           
                               as it leaves the 
                               faucet.
-------------------------------------------------------------------------------

* Since lead may be dissolved in plumbing fixtures, standards have been set for both the tap and source.

* Recommended level in water at which remedial action should be taken. No standards have been set yet.

General Water Quality Indicators are parameters used to indicate the presence of harmful contaminants. Testing for indicators can eliminate costly tests for specific contaminants. Generally, if the indicator is present, the supply may contain the contaminant as well. For example, you are probably most familiar with total coliform bacteria. These bacteria are present in all warrn blooded animals. Therefore, if they are present in the water supply, it is possible that sewage or animal manure may be contaminating the water. A total bacteria count includes all other types of bacteria. This.may indicate contamination from livestock. The pH value is also considered a general water quality indicator. High or low pHs can indicate how corrosive water is. Corrosive water may further indicate that metals like lead or copper are being dissolved in the water as it passes through distribution pipes. Table 2 shows some of the common general indicators.

Table 2. General water quality indicators

------------------------------------------------------------------------------
Indicator     Acceble Limit     Indicaton

pH Value      6.5 to 8.5         An important overall measure of water
                                 quality, pH can alter corrosivity and
                                 solubility of contaminants.  Low pH will
                                 cause pitting of pipes and fixtures or a
                                 metallic taste.  This may indicate that metal
                                 are being dissolved.  At high pH, the water
                                 will have a slippery feel or soda taste.
----------------------------------------------------------------------------
Total         <1 coliform        Possible bacterial or viral contamination
Coliform      /100 ml            from human sewage or animal manure.
----------------------------------------------------------------------------
Total         500 mg/1           Dissolved minerals like iron or manganese.
Dissolved                        High TDS also can indicate hardness (scaly
Solids                           deposits) or cause staining, or a salty,
(TDS)                            bitter taste.
----------------------------------------------------------------------------

Nuisance contaminants are a third category of contaminants that are often tested for. While these have no adverse health effects, they may make water unpallatable or reduce the effectiveness of soaps and detergents. Some nuisance contaminants also cause staining. Nuisance contaminants may include iron bacteria, hydrogen sulfide, and hardness. Table 3 shows some typical nuisance contaminants you may see on your water analysis report.

Hardness is one contaminant you will also commonly see on the report. Hard water causes soap and scaly deposits in plumbing and.decreased cleaning action of soaps and detergents. Hard water can also cause buildup on hot water heaters and reduce their effective lifetime. Table 4 will help you interpret the hardness parameters cited on your analysis.

Table 3: Common nuisance contaminants and their effects.

------------------------------------------------------------------------
contaminant         Acceptable Limit      Effects
------------------------------------------------------------------------
Chlorides           250 mg/l              Salty or brackish taste;
                                          corrosive; blackens & pits
                                          stanless steel.
------------------------------------------------------------------------
Copper (Cu)         1.3 mg/l              Blue-green stains on
                                          plumbing fixtures; bitter
                                          metalic taste.
------------------------------------------------------------------------
Iron (Fe)           0.3 mg/l              Metallic taste; discolored
                                          beverages; yellowish stains,
                                          stains laundry.
------------------------------------------------------------------------
Manganese (Mn)      0.05 mg/l             Black specks on fixtures;
                                          bitter taste.
------------------------------------------------------------------------
Sulfates (sO4)      250 mg/l              Bitter, medicinal taste;
                                          corrosive.
------------------------------------------------------------------------
Iron Bacteria       ----------            Orangeish to brownish slime
                                          in water.
------------------------------------------------------------------------

Table 4. Hardness classifications.

--------------------------------------------------------------------
Con,centration of hardness minerals in         Hardness Level
grains per gallon (GPG)
--------------------------------------------------------------------
below 1.0                                      soft
--------------------------------------------------------------------
1.0 to 3.5                                     slightly hard
--------------------------------------------------------------------
3.5 to 7.5                                     moderately hard
--------------------------------------------------------------------
7.5 to 10.5                                    hard
--------------------------------------------------------------------
10.5 and above                                 very hard
--------------------------------------------------------------------

Note that the units used in this table differ from those indicated in Figure 1. Hardness can be expressed by either of these units mg/i or a grain per gallon (gpg). A gpg is used exclusively as a hardness unit and equals approximately 17 mg/l or ppm. Those water supplies fallinc, in the hard to very hard categories may need to softened. However, as with all water treatment, you should careftilly consider the advantages and disadvantages to softening before making a purchase.

For a copy of our Fact Sheet Listing contact:

Agricultural and Biolo-ical Engineering Department
246 A-ricultural Engineering Buildina
University Park, PA 16802
Telephone: 814-865-7685 FAX Number: 814-863-1031


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