Water Quality Testing.docx

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Water Quality Testing: Drinking Water

The sulphide ion test for bacterial contamination is good. In surface waters, hydrogen sulphide is

formed under oxygen deficient conditions. Hydrogen sulphide is also produced from the

decomposition of sulphur containing organic compounds. The concentration of sulphide ion

becomes significant only at pH 10 or above.

Under acidic conditions, the concentration of hydrogen sulphide predominates. Hydrogen

sulphide is a weak acid, which ionizes to yield hydrosulphide (HS_-) and sulphide (S2) ions.

Hydrogen sulphide is extremely toxic to fish. Concentrations of total sulphide as low as 0.01

mg/L make the water unfit for uninhibited fish culture. Hydrogen sulphide also reduces the

aesthetics value of the water body due to foul color. The bacterial contamination can be tested

using H2S strip .

The water to be tested is to be filled in the bottle having H2S strip, and keep it in the incubator

;at 35degree centigrade for 14 to 16 hours. If the strip becomes black then the water is not fit for

human consumption as it is contaminated and bacterio logically not potable. This is the simple

and quick method as it needs no sterilization.

this is great, school teacher explaining water and its quality etc. In my earlier answers on

drinking water quality had given some basic concept on water-quality which all can remember

easily. I had explained C A T S which reads for:

C- clean and clear,

A- Alkaline about 7.5

T- taste appealing and pleasant

S- sterile, as being ascertained for your case usingH2S strip-test.

While doing this test to explain students,

1. pl do the test with good quality water and observe no discoluration even after say 12 hours,

2. also have some drain water sample and seen that the colur changes within an hour.

3. any others having medium contamination becomes discolured between 1 to12 hrs.



pl do a complete instructional cum demo exercise.

These concepts form activity exercise under EVS-Environmental Studies lessons.

In senior classes the demo can be dealt with remediation of water using simple Aquaguard andwith UV etc.

all the best

Is my water safe to drink?

If you do not monitor your water quality by having it tested at an accredited laboratory, youcannot tell whether your drinking water is safe or not.

Harmful bacteria, parasites, and viruses are invisible to the naked eye, so water that looks and

tastes good may not necessarily be safe to drink. These microbes can exist in both ground and

surface water supplies, and can cause immediate health effects if not properly treated for.

Just because you are not getting sick does not mean that your water is safe. Certain chemical

contaminants that are sometimes found in a water source can cause long term health problems

that may take years to develop. This stresses the importance of having an effective treatment

system in place to ensure that your water is being treated to a satisfactory level.

What tests should I have done on my drinking water and how often?



There are many useful tests available to help determine the health, safety and performance of

your water supply depending upon its type and location. Your local health department can assist

you in selecting tests important for assessing your drinking water.

A number of commercial laboratories carry different water quality packages that include a

variety of tests to assess water potability.

Basic drinking and household use suitability

Basic Water Potability Test packages include tests for:

Coliform Bacteria Nitrate

pH

Sodium

Chloride

Fluoride

Sulphate

Iron

Manganese

Total Dissolved Solids

Hardness

Coliform bacteria tests are used as an indicator test for the presence of microorganisms in the

water that are potentially harmful to human health. Nitrate is a common contaminant found

mainly in groundwater. High nitrate concentrations can be particularly dangerous for babies

under six months, since nitrate interferes with ability of blood to carry oxygen. Ions such assodium, chloride, sulphate, iron and manganese can impart objectionable taste or odor to water.

Excessive amounts of sulfate can cause a laxative effect or gastrointestinal irritation, along with

a noticeable taste. Excessive amounts of fluoride can cause dental problems. Total dissolved

solids represent the amount of inorganic substances (e.g. iron, salts) that are dissolved in the

water. High total dissolved solids (TDS) can reduce the palatability of water or cause health



problems if specific constituent elements are at high levels.

Other tests may be appropriate if there is a particular reason to suspect that a specific

contaminant may be present or if additional background information is desired. Groundwater

sources are sometimes tested for parameters such as arsenic, selenium and uranium. Both surface

and groundwater sources are also sometimes tested for pesticide contamination.

Private drinking water supplies should undergo basic testing annually at a minimum. Drinking

water supplies obtained from shallow wells and surface water sources should be tested more

frequently, such as seasonally as they are highly susceptible to contamination.

If you have critical water treatment equipment it is important to test both your drinking water at

the tap and your source water. The testing of both will help you interpret if your treatment

system is performing correctly or whether the quality of your source water has changed.

The following is a list of additional potential tests that are sometimes tested for, depending on

the detail of information required.

Bicarbonate Calcium Carbonate Tannin and lignin

Hydroxide Magnesium cyanide orthophosphate

bromate Conductivity Sulfide – as hydrogen sulfide radon

Boron Total

Alkalinity

Chloride trihalomethanes

Turbidity Ammonia, as

nitrogen

Potassium Sulfate reducing

bacteria

Aluminum Arsenic Barium Heterotrophic Plate

Count

Cadmium Chromium Copper E. Coli

Dissolved organic Lead Selenium cyanobacteria



carbon

Zinc Uranium Total phosphorous Faecal Coliform

True Colour pesticides Dissolved oxygen within 2 minutes

of collection

Iron bacteria

Here are some examples of water tests in Alberta and Saskatchewan:

Typical Alberta drinking water test suite to assess drinking water at the tap (Alberta

Health Region labs)

Ground water test suite to assess a source water used as a drinking water supply

(Saskatchewan Watershed Authority)

Surface water test suite to assess a source water used as a drinking water supply

(Saskatchewan Watershed Authority)

Microbiological Indicators

Laboratory results may provide information on levels of Total

Coliforms, Escherichia coli (E-Coli), and Heterotrophic Plate

Count (HPC) which are used as microbiological indicators of

the microbiological quality of the water. This section will briefly outline the rationale for including these indicators and

their significance.

Total Coliform (TC)

The presence of Total Coliform bacteria may indicate contamination in a water supply. The

presence of only Total Coliforms is not necessarily a health risk, but it does require a further

investigation of the water system. The presence of any coliform bacteria indicates that the

drinking water is potentially unsafe and unsatisfactory.

http://www1.agric.gov.ab.ca/$department/deptdocs.nsf/all/wqe11082/$FILE/ab_lab_test.pdf

http://www1.agric.gov.ab.ca/$department/deptdocs.nsf/all/wqe11082/$FILE/sask_groundwater.pdf

http://www1.agric.gov.ab.ca/$department/deptdocs.nsf/all/wqe11082/$FILE/sask_surfacewater.pdf

http://www1.agric.gov.ab.ca/$department/deptdocs.nsf/all/wqe11082/$FILE/sask_surfacewater.pdf

http://www1.agric.gov.ab.ca/$department/deptdocs.nsf/all/wqe11082/$FILE/sask_groundwater.pdf

http://www1.agric.gov.ab.ca/$department/deptdocs.nsf/all/wqe11082/$FILE/ab_lab_test.pdf



The absence of coliforms in a water supply is usually interpreted as evidence of safe drinking

water. This indicates that the water is free of pathogens and contains a low risk of waterborne

infectious disease.

Escherichia coli (EC / E. Coli) E. coli has been demonstrated to be a specific indicator for the presence of fecal (human or

animal waste) contamination. This is a potentially dangerous situation. Immediate steps need to

be taken to disinfect the water, remove the source of contamination or find an appropriate

alternate source. Water containing E. Coli bacteria must not be consumed or used where the

water could be a health hazard such. Even brushing your teeth with this water can pose a

significant health risk.

Heterotrophic Plate Count (HPC)

Although this test is not normally part of the standard testing for homeowners it can provide

some useful information regarding the microbiological quality of your water. The HPC bacteria

enumerates both aerobic and facultative aerobic bacteria found in water. These bacteria are not

normally used as an indicator of disease, and bacteria in this group are not usually directly

associated with a specific illness or disease. However, bacteria within the HPC can cause

disease, both as primary pathogens and opportunistic pathogens. The HPC is useful for

measuring changes during water treatment and distribution. It is valuable for checking quality of

finished water in a distribution system as an indicator of microbial regrowth and sediment build-

up in slow-flow sections and dead ends.



More comprehensive drinking and household use suitabilityGroundwater

Recommendations for Testing Rural Water Sources for Drinking and Domestic

Water Ground Water: test 2 times/year N.B. For each Level, be sur e to sample the water before any tr eatment devices.

Level A - Basic Ground Water Suite, 3 parameters + targeted problems

This level of testing provides very little information but it is cheap (about $60), and much better

than not having any tests at all. Sample and record water quality test results at least twice per

year.

Parameter Significance

Total Coliform Identifies potential microbial contamination. If any Total Coliform are

detected, then water should be re-tested and additionally tested for Faecal

Coliform and E. Coli

Nitrate Identifies potential contamination from nitrates, septic systems, corrals,

etc.

Total Dissolved

Solids or

Conductivity

Identifies whether water is mineralized; levels above 500 mg/L indicate

more comprehensive testing is needed for ions and salts

Other suspected

problems

Many wells have unique problems with such parameters as arsenic, iron,

manganese, hardness, sulphate, sodium, etc.

Level B - Operational Ground Water Suite, targeted parameters

This is a focused suite to track source water quality problems and manage water treatment (about

$60+ additional problems). The parameters recommended are those where problems were

detected from the Level C Diagnostic Suite. On-site turbidity and dissolved oxygen are

beneficial if possible.




Total Coliform Identifies potential microbial contamination. If any Total

Coliform are detected, then water should be re-tested and

additionally tested for Faecal Coliform and E. Coli

Total Dissolved Solids or

Conductivity

Identifies TDS changes; significant changes (say more than

100 mg/L up or down) may identify change in water quality).

Track and determine the reason for changes, and ensure the

treatment process is not impaired by the change.

Turbidity Turbidity testing at the time sampled (within 2 minutes of

collection) should be similar; if Values differ, this may be an

indicator the groundwater is under the influence of surfacewater, flooding, etc.

Parameters identified as

problems from Level C

Diagnostic Ground Water Suite

Regularly re-test any parameters that exceeded guidelines, as

determined by the Level C Diagnostic Testing (e.g. arsenic,

iron, manganese, hardness, sulphate, sodium, etc.)

Level C Diagnostic Ground Water Suite, 39 parameters

This suite is very similar to the Saskatchewan Watershed Authority Rural Water Quality

Advisory Program (The Saskatchewan suite is subsidized by the Province, which charges clients

$100). This full cost of this diagnostic suite is around $400. It is very useful in determining

initial water quality problems, and designing water treatment systems (effective treatment will

subsequently pay future dividends because treatment success will be more likely.) On-site

turbidity and dissolved oxygen are beneficial if possible.

Bicarbonate Calcium Carbonate Chloride

Hydroxide Magnesium pH Potassium

Sodium TDS or Conductivity Sulphate Sulphide



Sum of

Ions

Total Alkalinity Total Hardness True Colour

Turbidity Ammonia, as

nitrogen

Nitrate Dissolved organic

carbon

Aluminum Arsenic Barium Boron

Cadmium Chromium Copper Fluoride

Iron Lead Manganese Selenium

Zinc Uranium Total Coliform Faecal Coliform

E. Coli Heterotrophic Plate

Count

Dissolved oxygen within 2 minutes of

collection

Surface Water


Water Surface Water: test 2 - 4 times/year

(and Ground Water Under Direct Influence of Surface Water: GWUDI):

N.B. For each Level, be sur e to sample the water before any tr eatment devices.

N.B. I f GWUDI is tested, other parameters may be necessary (e.g. arseni c)

Level A - Basic Surface Water Suite, 3 parameters + targeted problems

This level of testing provides very little information but it is cheap (about $60), and much better

than not having any tests at all. Sample and record water quality test results at least twice per

year.



detected, then water should be re-tested and additionally tested for

Faecal Coliform and E. Coli



Turbidity Identifies potential water quality change and contamination etc.

Total Dissolved Solids

or Conductivity

Identifies whether water is mineralized; levels above 500 mg/L

indicate more comprehensive testing is needed for ions and salts

Other suspected

problems

Many surface water sources have unique problems with such

parameters as algae, chlorophyll a, iron, manganese, hardness,

ammonia, nitrate, etc.

Level B - Operational Surface Water Suite, targeted parameters

This suite is a focused suite to track source water quality problems and manage water treatment

(about $60+ additional problems). The parameters recommended are those where problems were

detected from the Level C Diagnostic Suite. On-site turbidity and dissolved oxygen are beneficial if possible.



detected, then water should be re-tested and



Conductivity

Identifies TDS changes; significant changes (say more than 100 mg/L

up or down) may identify change in water quality).

Track and determine the reason for changes, and ensure the treatment

process is not impaired by the change.

Turbidity Turbidity testing at the time sampled (within 2 minutes of collection)

should be similar; if Values differ, this may be an indicator the

groundwater is under the influence of surface water, flooding, etc.


problems from

Level C Diagnostic

Surface Water Suite


determined by the Level C Diagnostic Testing (e.g. arsenic, iron,

manganese, hardness, sulphate, sodium, etc.)



Level C Diagnostic Surface Water Suite, 30 parameters

This suite is very similar to Saskatchewan Watershed Authority Rural Water Quality Advisory

Program (The Saskatchewan suite is subsidized by the Province, which charges clients $100).

This full cost of this diagnostic suite is around $300. It is very useful in determining initial water

quality problems, and designing water treatment systems (effective treatment will subsequently

pay future dividends because treatment success will be more likely.) On-site turbidity and

dissolved oxygen are beneficial if possible.

Bicarbonate Calcium Carbonate Chloride

Hydroxide Magnesium pH Potassium

Sodium TDS or Conductivity Sulphate Sum of Ions

Total Alkalinity Hardness True Colour Turbidity

Ammonia, as

nitrogen

Nitrate Ortho-

phosphate

Total

Phosphorus

Dissolved Organic

Carbon

Iron Manganese Mercury

Faecal Coliform Heterotrophic Plate Count Total

Coliform

E. Coli

Chlorophyll a Dissolved oxygen within 2 minutes

of collection

Treated Water


Water Treated Water:

Test water quality after the treatment system every time the source water is

sampled (2 - 4 times/year)

Rationale for Testing After Treatment



Most water supplies will require some degree of treatment. For example, Environment Canada

estimates that 20 to 40% of wells across the country have problems with coliform or nitrate. In

Alberta and Saskatchewan, where ground water supplies tend to be mineralized, over 90% of the

wells will exceed one or more Guideline for Canadian Drinking Water Quality. Most of these

problems are not health-related, but it is estimated that about 30% or more of privately-owned

wells will have water quality problems that could affect human health.

Testing the water quality of untreated water sources helps people understand what water quality

problems exist, and what measures can be taken to treat the water and manage the water supply.

It is equally important to test water quality after the water treatment system. This type of

monitoring is necessary to ensure the treatment system is performing as designed, and to ensure

the safety of the drinking water supplied in a rural or remote location.

The treated water tests should be done at the same time as the untreated water quality tests.

Problems should be addressed immediately. Records should be kept. Should a water quality

concern exist affecting health, consult a local public health inspector or doctor.

Treated Water Suite, targeted parametersThis suite is a focused suite to track source water quality problems and manage water treatment.

The parameters recommended are those where problems were detected from the Level C

Diagnostic Suite. On-site turbidity and dissolved oxygen are beneficial if possible.


Total Coliform Identifies potential microbial contamination. If any Total

Coliform are detected, then water should be re-tested and



Conductivity

Identifies TDS changes; significant changes (say more than 100

mg/L up or down) may identify change in water quality).

Track and determine the reason for changes, and ensure the



treatment process is not impaired by the change.

Turbidity Turbidity testing at the time sampled (within 2 minutes of

collection) should be similar; if Values differ, this may be an

indicator the groundwater is under the influence of surface water,flooding, etc.


problems from

Level C Diagnostic Surface or

Ground

Water Suite


determined by the Level C Diagnostic Testing

(e.g. arsenic, iron, manganese, hardness, sulphate, sodium, etc.)

N.B. It is beneficial to periodically test the Treated Water for the full Diagnostic Suite (say onceevery 3 or 4 years). This is a measure of safeguarding health and verifies treatment effectiveness.

Who's responsible for drinking water safety?

Privately owned water systems for individuals are not regulated by either the provincial or

federal governments. It is the responsibility of the individual owner to ensure their water is of

good quality.

Provincial agencies along with the local health department can provide information, advice,

treatment options and interpretation of water quality analyses, but ultimately the final selection

and cost associated with either bottled water or water treatment devices, including maintenance

and follow-up sampling, are the responsibility of the individual owner.

Individuals accessing or purchasing water from a source other than their own private supply,

such as from a pipeline or tankloader, should understand the quality of the water and their

agreement with the supplier. Once again, it is the responsibility of the individual to ensure that

the proper water treatment and safety measures are in place, unless the water supplier is

guaranteeing potable drinking water.



Sources of Sulfate and Hydrogen

Sulfide in Drinking Water

Sulfates and Hydrogen Sulfide

Sulfates are a combination of sulfur and oxygen and are a part of naturally occurring minerals insome soil and rock formations that contain groundwater. The mineral dissolves over time and isreleased into groundwater.

Sulfur-reducing bacteria, which use sulfur as an energy source, are the primary producers of large quantities of hydrogen sulfide. These bacteria chemically change natural sulfates in water to hydrogen sulfide. Sulfur-reducing bacteria live in oxygen-deficient environments such as deepwells, plumbing systems, water softeners and water heaters. These bacteria usually flourish onthe hot water side of a water distribution system.

Hydrogen sulfide gas also occurs naturally in some groundwater. It is formed from decomposingunderground deposits of organic matter such as decaying plant material. It is found in deep or shallow wells and also can enter surface water through springs, although it quickly escapes to theatmosphere. Hydrogen sulfide often is present in wells drilled in shale or sandstone, or near coalor peat deposits or oil fields.

Occasionally, a hot water heater is a source of hydrogen sulfide odor. The magnesium corrosioncontrol rod present in many hot water heaters can chemically reduce naturally occurring sulfatesto hydrogen sulfide.

Indications of Sulfate and Hydrogen Sulfide

Sulfate

Sulfate minerals can cause scale buildup in water pipes similar to other minerals and may beassociated with a bitter taste in water that can have a laxative effect on humans and younglivestock. Elevated sulfate levels in combination with chlorine bleach can make cleaning clothesdifficult. Sulfur-oxidizing bacteria produce effects similar to those of iron bacteria. They convertsulfide into sulfate, producing a dark slime that can clog plumbing and/or stain clothing.Blackening of water or dark slime coating the inside of toilet tanks may indicate a sulfur-oxidizing bacteria problem. Sulfur-oxidizing bacteria are less common than sulfur-reducing bacteria.

Hydrogen Sulfide

Hydrogen sulfide gas produces an offensive "rotten egg" or "sulfur water" odor and taste in thewater. In some cases, the odor may be noticeable only when the water is initially turned on or when hot water is run. Heat forces the gas into the air which may cause the odor to be especiallyoffensive in a shower. Occasionally, a hot water heater is a source of hydrogen sulfide odor. The



magnesium corrosion control rod present in many hot water heaters can chemically reducenaturally occurring sulfates to hydrogen sulfide.

A nuisance associated with hydrogen sulfide includes its corrosiveness to metals such as iron,steel, copper and brass. It can tarnish silverware and discolor copper and brass utensils.

Hydrogen sulfide also can cause yellow or black stains on kitchen and bathroom fixtures. Coffee,tea and other beverages made with water containing hydrogen sulfide may be discolored and theappearance and taste of cooked foods can be affected.

High concentrations of dissolved hydrogen sulfide also can foul the resin bed of an ion exchangewater softener. When a hydrogen sulfide odor occurs in treated water (softened or filtered) andno hydrogen sulfide is detected in the non-treated water, it usually indicates the presence of someform of sulfate-reducing bacteria in the system. Water softeners provide a convenientenvironment for these bacteria to grow. A "salt-loving" bacteria, that uses sulfates as an energysource, may produce a black slime inside water softeners.

Potential Health Effects Sulfate

Sulfate may have a laxative effect that can lead to dehydration and is of special concern for infants. With time, people and young livestock will become acclimated to the sulfate and thesymptoms disappear. Sulfur-oxidizing bacteria pose no known human health risk. TheMaximum contaminate level is 250 mg/L.

Hydrogen Sulfide

Hydrogen sulfide is flammable and poisonous. Usually it is not a health risk at concentrations

present in household water, except in very high concentrations. While such concentrations arerare, hydrogen sulfide's presence in drinking water when released in confined areas has beenknown to cause nausea, illness and, in extreme cases, death. Water with hydrogen sulfide alonedoes not cause disease. In rare cases, however, hydrogen sulfide odor may be from sewage

pollution which can contain disease-producing contaminants. Therefore, testing for bacterial

contamination and Sulfate Reducing Bacteria is highly recommended.

Water Testing

Sulfate

The Option 1 testing kit includes the sulfate test, but for sulfur problems the laboratory must benotified to provide a special container that has a chemical preservative. The testing kits includethe sampling instructions, a questionnaire, and information on returning the sample. HydrogenSulfide- If this is a problem that laboratory must be told in advance to provide the necessarysampling container with preservatives.

Since hydrogen sulfide is a gas that is dissolved in water and can vaporize (escape) from it,laboratory analysis of hydrogen sulfide in water requires the sample be stabilized immediately



following collection. Since the odor may be caused by a number of factors, it is critical that thequestionnaire be completed and it is highly recommended that both the Option 1 and Option 3water testing packages are conducted..

Interpreting Sulfate and HydrogenSulfide Test Results

Sulfate

The Environmental Protection Agency (EPA) standards for drinking water fall into twocategories -- Primary Standards and Secondary Standards. Primary Standards are based onhealth considerations and are designed to protect people from three classes of toxic pollutants -- pathogens, radioactive elements and toxic chemicals. Secondary Standards are based on taste,odor, color, corrosivity, foaming and staining properties of water. Sulfate is classified under thesecondary maximum contaminant level (SMCL) standards. The SMCL for sulfate in drinkingwater is 250 milligrams per liter (mg/l), sometimes expressed as 250 parts per million (ppm).

Hydrogen Sulfide

Although many impurities are regulated by Primary or Secondary Drinking Water Standards set by the EPA, hydrogen sulfide is not regulated because a concentration high enough to be adrinking water health hazard also makes the water unpalatable. The odor of water with as little as0.5 ppm of hydrogen sulfide concentration is detectable by most people. Concentrations less than1 ppm give the water a "musty" or "swampy" odor. A 1-2 ppm hydrogen sulfide concentrationgives water a "rotten egg" odor and makes the water very corrosive to plumbing. Generally,hydrogen sulfide levels are less than 10 ppm, but have been reported as high as 50 to 75 ppm.

Options

If excessive sulfate or hydrogen sulfide is present in your water supply, you have three basicoptions:

1) Obtain an alternate water supply, bottled water, or use some type of treatment to remove theimpurity. The need for an alternate water supply or should be established before making aninvestment in treatment equipment or an alternate supply. Based the decision the results of achemical analysis water, by a reputable laboratory, and after consulting with your physician tohelp you evaluate the level of risk. It may be possible to obtain a satisfactory alternate water supply by drilling a new well in a different location or a shallower or deeper well in a differentaquifer.

2)Another alternate source of water is bottled water that can be purchased in stores or direct from bottling companies. This alternative might be considered especially when the primary concern iswater for food preparation and drinking.

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3)The typical recommendation is the installation of a whole-house treatment system. The sectionof the most cost effective system is a function of the overall water quality, cause of the sulfur odor, and other water treatment issues.

Sulfate Treatment

Several methods of removing sulfate from water are available. The treatment method selecteddepends on many factors including the level of sulfate in the water, the amount of iron andmanganese in the water, and if bacterial contamination also must be treated. The option youchoose also depends on how much water you need to treat.

For treating small quantities of water (drinking and cooking only) the typical methods may bedistillation or reverse osmosis. The most common method of treating large quantities of water ision exchange. This process works similar to a water softener. Ion-exchange resin, containedinside the unit, adsorbs sulfate. When the resin is loaded to full capacity with sulfate, treatmentceases. The resin then must be "regenerated" with a salt (sodium chloride) brine solution before

further treatment can occur.

Distillation boils water to form steam that is then cooled and then recondense the water.Minerals, such as sulfate, do not vaporize with the steam and are left behind in the boilingchamber. Reverse osmosis membranes have a porosity that permits water molecules to passthrough but leaves the large ions in solution.

Hydrogen Sulfide

Hydrogen sulfide may be temporarily controlled by conducting a shock chlorination /disinfection of the well or water source. Please visit the Shock Chlorination page to get moreinformation on this protocol. If the problem with the well is because of Sulfate ReducingBacteria, a high level of chlorination, mixing, and turbulence may be needed.

If hydrogen sulfide odor is associated primarily with the hot water system, a hot water heater modification may reduce the odor. Replacing the water heater's magnesium corrosion control rodwith one made of aluminum or another metal may improve the situation.

To remove low levels of hydrogen sulfide, install an activated carbon filter. The filter must bereplaced periodically to maintain performance. Frequency of replacement will depend on dailywater use and concentration of hydrogen sulfide in the water.

Hydrogen sulfide concentrations up to about 5 to 7 ppm can be removed using an oxidizingfilter. These filters are similar to the units used for iron treatment . This filter contains sand witha manganese dioxide coating that changes hydrogen sulfide gas to tiny particles of sulfur that aretrapped inside the filter. The sand filter must be backwashed regularly and treated with potassium permanganate to maintain the coating. Hydrogen sulfide concentrations exceeding 7to 10 ppm can be removed by injecting an oxidizing chemical such as household bleach or potassium permanganate followed up by filtration. The oxidizing chemical should enter thewater upstream from the storage or mixing tank to provide at least 30- 45 minutes of contact

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time between the chemical and water. The length of the holding time is a function of thechemical dosage, tank configuration, and water temperature. Sulfur particles can then beremoved using a sediment filter and the excess chlorine can be removed by activated carbonfiltration. When potassium permanganate is used a manganese greensand filter is recommended.

Often the treatment for hydrogen sulfide is the same as for iron and manganese, for moreinformation please visit the iron and manganese webpage.

In Closing

Sulfates and hydrogen sulfide are both common nuisance contaminants. Although neither isusually a significant health hazard, sulfates can have a temporary laxative effect on humans andyoung livestock. Sulfates also may clog plumbing and stain clothing. Hydrogen sulfide producesan offensive "rotten egg" odor and taste in the water, especially when the water is heated.

Treatment options depend on the form and quantities in which sulfates and/or hydrogen sulfide

occur in untreated water- Therefore, it is critical that a comprehensive water analysis beconducted.. Small quantities of sulfate may be removed from water using distillation or reverseosmosis, while large quantities may be removed using ion exchange treatment. Hydrogen sulfidegas may be associated with the presence of Sulfate Reducing Bacteria. Hydrogen sulfide may bereduced or removed by shock chlorination, water heater modification, activated carbon filtration,oxidizing filtration or oxidizing chemical injection. Often treatment for hydrogen sulfide is thesame as for iron and manganese, allowing the removal of all three contaminants in one process.

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Water Quality Testing.docx