Common Water Quality Problems and Their Methods of Treatment

8/7/2019 Common Water Quality Problems and Their Methods of Treatment

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Common Water Quality Problems and Their Methods ofTreatmentThe following chart is intended to serve as a general guide for consumers in determining thecause of problems with their water that can be felt, smelled, tasted, or seen. In some cases,these symptoms may indicate a serious problem -- in others, only the taste and smell of tap

water (its aesthetics) may be affected.A. Sense of Feeling

Impurity orContaminant

Symptom Cause Health Effects Means of Treatment

Hard Water Soap curd, and scum inwash basins & bathtub.Whitish scale deposits inpipes, water heater & teakettle.

Calcium(limestone) andmagnesiumsalts.

Aesthetic only.However if consumed,could lead to kidney/bladder stones

Cation exchangewater softener orreverse osmosis.

Grittiness Abrasive texture to water

when washing or residualleft in sink.

Excessively fine

sand, silt inwater.

Various -- sand could

trap contaminants

Sand trap in ultra-

filtration.

B. Sense of Smell



Odor Musty, earthyor wood smell.

Generally, harmlessorganic matter.

Aesthetic only Activated carbon filter.

Chlorine smell. Excessivechlorination.

Could occur fromformation ofdisinfectionbyproducts

Dechlorinate with activatedcarbon filter.

Rotten eggodor -tarnishedsilverware.

1. Dissolvedhydrogen sulfidegas.

2. Presence ofsulfate reducingbacteria in rawwater.

Various effects 1. Manganese greensandfilter - constantchlorination followed byfiltration/ dechlorination.

2. Constant chlorinationfollowed by activatedcarbon filter.

Hot water,rotten eggodor.

Action ofmagnesium rod inhot water heater.

Various Effects Remove magnesium rodfrom heater.

Detergent odor,water foamswhen drawn.

Seepage of septicdischarge intounderground watersupply.

Disease-causingmicroorganisms maybe present

1. Locate and eliminatesource of seepage - thenheavily chlorinate well.

2. Activated carbon filterwill adsorb limited amount.


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Gasoline or oil(hydro-carbon)smell.

Leak in fuel oil tankor gasoline tankseeping into watersupply.

Fuel components maybe toxic orcarcinogenic

No residential treatment.Locate and eliminateseepage.

Methane gas. Naturally occurringcaused by decaying

organics.

Various effects Aeration system andrepump.

Phenol smell(chemicalodor).

Industrial wasteseeping into surfaceor ground watersupplies.

Various --compounds may becarcinogenic

Activated carbon filter willadsorb short-term.

C. Sense of Taste


Symptom Cause HealthEffects

Means of Treatment

Taste Salty orbrackish.

High sodium content. Aesthetic only1. Deionize drinking wateronly with disposable mixedbed - anion/cation resins; or

2. Reverse osmosis; or

3. Home distillation system.

Alkali taste. High dissolved mineralcontaining alkalinity.(Stained aluminumcookware.)

Aesthetic onlyReduce by reverse osmosis.

Metallic

taste.

1. Very low pH water (3.0-

5.5).

2. Heavy iron concentrationin water above 3.0 ppm Fe.

3. Leaching of lead andcopper

Various --

depends oncause

1. Correct with calcite type

filter (see Acid Water).

2. (See Iron Water).

D. Sense of Sight



Turbidity Dirt, salt, clay. Suspended matter insurface water pond,stream or lake.

Turbid water maycontain diseasecausingmicroorganisms

"Calcite" or Neutralize(media) type filter - upto 50 ppm

Sand grit, silt or claysubstances.

Well sand from newwell or defective well

Turbid water maycontain disease

Sand trap and/or newwell screen


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screen. causingmicroorganisms

Rust in water. Acid water causingiron "pick-up."


Neutralizing calcite filterto correct low pHacidity and removeprecipitated iron

Gray string-likefiber.

Organic mater in rawwater algae, etc.


Constant chlorinationfollowed by activatedcarbon filter todechlorinate.

Acid water Green stains onsinks and silver,porcelain bathroomfixtures. Blue-greencast to water.

Water which has highcarbon dioxidecontent (pH below6.8) reacting withbrass and copperpipes and fittings.

Could lead tohealth effects ifacid water causesleaching of leadand copper

1. Neutralizing calcitefilter down to pH of 5.5,or

2. Calcite/ Magnesia -oxide mix (5 to 1) forhigher flow rate and tocorrect very low pHwater.

3. Soda ash chemicalfeed followed byfiltration.

Discoloredwater red,"Iron" water

Brown-red stainson sinks and otherporcelainbathroom fixtures.Water turnsbrown-red incooking or uponheating. Clothing

becomesdiscolored.

1. Dissolved iron ininfluent (more than0.3 ppm Fe+) waterappears clear whenfirst drawn at coldwater faucet. Above0.3 ppm Fe causesstaining.

Various effects 1. Can remove 0.5 ppmof Fe+ for everygrain/gal of hardness to10 ppm with watersoftener and minimumpH of 6.7.

2. Over 10 ppm Fe+chlorination with

sufficient retention tanktime for full oxidationfollowed by filtration/dechlorination.

3. In warm climatesresidual aerator andfiltration willsubstantially reduceiron content.

2. Precipitate iron(water will not clearwhen drawn).

Various effects 1. Up to 10 ppm ironremoved by manganesegreensand filter, if pH

6.7 or higher, or;

2. Manganese treated,non-hydrous aluminumsilicate filter where pHof 6.8 or higher andoxygen is 15% of totaliron content.

3. Downflow water


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softener with goodbackwash, up to 1.0ppm Fe. Above 1 ppmto 10 ppm use calcitefilter followed by

downflow watersoftener.

Calcite media type filterto remove precipitatediron.

Brownish cast doesnot precipitate.

Iron pick-up from oldpipe with waterhaving a pH below6.8. Organic(bacterial) iron.

Various effects 1. Treat well to destroyiron bacteria withsolution of hydrochloricacid then constantchlorination followed byactivated carbon mediafiltration anddechlorination.

2. Potassiumpermanganate chemicalfeed followed byfiltration.

Reddish color inwater sample afterstanding 24 hours.

Colloidal iron. Various effects Constant chlorinationfollowed by activatedcarbon media filterdechlorination.

Yellow water Yellowish cast towater after softeningand/or filtering.

Tannins (humicacids) in water frompeaty soil anddecaying vegetation.

Various effects 1. Adsorption viaspecial macro-porousType I anion exchangeresin regenerated withsalt (NaCl) up to 3.0ppm.

2. Manganesegreensand ormanganese treatedsodium alumino-silicateunder proper set ofconditions.

Milky water Cloudiness of waterwhen drawn.

1. Some precipitantsludge createdduring heating ofwater.

2. High degree of airin water from poorlyfunctioning pump.

3. Excessivecoagulant-feed beingcarried through filter.

1. Various effects

2. Aesthetic only

3. Various effects

1. Blow down domesticor commercial hotwater heater tankperiodically.

2. Water will usuallyclear quickly uponstanding.

3. Reduce coagulantquantity being fed,service filters properly.

Very high Blackening and 1. Excessive salt Various effects 1. Use other chloride


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chloridecontent inwater

pitting of stainlesssteel sinks andstainless ware incommercialdishwashers

content.

2. High temperaturedrying createschlorideconcentration

acceleratingcorrosion.

resistant metals.

2. Reduce totaldissolved solids byreverse osmosis.

Note: This information has been taken principally from a paper titled "Sensitivity: A KeyWater Conditioning Skill" by Wes McGowan. The paper was published in Water Technology,

September/October 1982.

According to recent news and reports, most tap and well water in the U.S. are not safe fordrinking due to heavy industrial and environmental pollution. Toxic bacteria, chemicals andheavy metals routinely penetrate and pollute our natural water sources making people sickwhile exposing them to long term health consequences such as liver damage, cancer andother serious conditions. We have reached the point where all sources of our drinking water,including municipal water systems, wells, lakes, rivers, and even glaciers, contain somelevel of contamination. Even some brands of bottled water have been found to contain highlevels of contaminants in addition to plastics chemical leaching from the bottle.

A good water filtration system installed in your home is the only way to proactively monitorand ensure the quality and safety of your drinking water. Reverse osmosis water purificationsystems can remove 90-99% of all contaminants from city and well water to deliver healthydrinking water for you and your family.

Microorganisms

Contaminant

MCL or

TT1

(mg/L)2

Potential Health Effects from

Ingestion of Water

Sources of Contaminant in

Drinking Water

Cryptosporidium TT 3 Gastrointestinal illness (e.g.,diarrhea, vomiting, cramps)

Human and fecal animalwaste

Giardia lamblia TT3 Gastrointestinal illness (e.g.,diarrhea, vomiting, cramps)

Human and animal fecalwaste

Heterotrophic platecount

TT3 HPC has no health effects; it is ananalytic method used to measurethe variety of bacteria that arecommon in water. The lower theconcentration of bacteria indrinking water, the bettermaintained the water system is.

HPC measures a range ofbacteria that are naturallypresent in the environment

Legionella TT3 Legionnaire's Disease, a type ofpneumonia

Found naturally in water;multiplies in heating systems
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Total Coliforms(including fecalcoliform andE.Coli)

5.0%4 Not a health threat in itself; it isused to indicate whether otherpotentially harmful bacteria maybe present5

Coliforms are naturallypresent in the environment;as well as feces; fecalcoliforms and E. colionlycome from human andanimal fecal waste.

Turbidity TT3

Turbidity is a measure of thecloudiness of water. It is used toindicate water quality andfiltration effectiveness (e.g.,whether disease-causingorganisms are present). Higherturbidity levels are oftenassociated with higher levels ofdisease-causing microorganismssuch as viruses, parasites andsome bacteria. These organismscan cause symptoms such asnausea, cramps, diarrhea, andassociated headaches.

Soil runoff

Viruses (enteric) TT3 Gastrointestinal illness (e.g.,diarrhea, vomiting, cramps)

Human and animal fecalwaste

Disinfection Byproducts

Contaminant

MCL or

TT1

(mg/L)2


Ingestion of Water

Sources of Contaminant

in Drinking Water

Bromate 0.010 Increased risk of cancer Byproduct of drinking waterdisinfection

Chlorite 1.0 Anemia; infants & youngchildren: nervous system effects Byproduct of drinking waterdisinfectionHaloacetic acids(HAA5)

0.060 Increased risk of cancer Byproduct of drinking waterdisinfection

TotalTrihalomethanes(TTHMs)

0.10----------

0.080

Liver, kidney or central nervoussystem problems; increased riskof cancer

Byproduct of drinking waterdisinfection

Disinfectants

Contaminant MRDL1

(mg/L)2Potential Health Effects from

Ingestion of WaterSources of Contaminant in

Drinking Water

Chloramines (asCl2)

MRDL=4.01 Eye/nose irritation; stomachdiscomfort, anemia

Water additive used tocontrol microbes

Chlorine (as Cl2) MRDL=4.01 Eye/nose irritation; stomachdiscomfort

Water additive used tocontrol microbes

Chlorine dioxide MRDL=0.81 Anemia; infants & young Water additive used to
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(as ClO2) children: nervous system effects control microbes

Inorganic Chemicals

ContaminantMCL or TT1

(mg/L)2

Potential Health Effects

from Ingestion of Water

Sources of Contaminant in

Drinking Water

Antimony 0.006 Increase in blood cholesterol;decrease in blood sugar

Discharge from petroleumrefineries; fire retardants;ceramics; electronics; solder

Arsenic 0.010as of

01/23/06

Skin damage or problems withcirculatory systems, and mayhave increased risk of gettingcancer

Erosion of natural deposits;runoff from orchards, runofffrom glass &electronicsproduction wastes

Asbestos(fiber >10micrometers)

7 MFL Increased risk of developingbenign intestinal polyps

Decay of asbestos cement inwater mains; erosion ofnatural deposits

Barium 2 Increase in blood pressure Discharge of drilling wastes;discharge from metalrefineries; erosion of naturaldeposits

Beryllium 0.004 Intestinal lesions Discharge from metalrefineries and coal-burningfactories; discharge fromelectrical, aerospace, anddefense industries

Cadmium 0.005 Kidney damage Corrosion of galvanized pipes;erosion of natural deposits;

discharge from metalrefineries; runoff from wastebatteries and paints

Chromium (total) 0.1 Allergic dermatitis Discharge from steel and pulpmills; erosion of naturaldeposits

Copper TT8;Action

Level=1.3

Short term exposure:Gastrointestinal distress

Long term exposure: Liver orkidney damage

People with Wilson's Diseaseshould consult their personaldoctor if the amount of copperin their water exceeds theaction level

Corrosion of householdplumbing systems; erosion ofnatural deposits

Cyanide (as freecyanide)

0.2 Nerve damage or thyroidproblems

Discharge from steel/metalfactories; discharge fromplastic and fertilizer factories

Fluoride 4.0 Bone disease (pain and Water additive which
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tenderness of the bones);Children may get mottledteeth

promotes strong teeth;erosion of natural deposits;discharge from fertilizer andaluminum factories

Lead TT8;Action

Level=0.015

Infants and children: Delays inphysical or mental

development; children couldshow slight deficits in attentionspan and learning abilities

Adults: Kidney problems; highblood pressure

Corrosion of householdplumbing systems; erosion of

natural deposits

Mercury(inorganic)

0.002 Kidney damage Erosion of natural deposits;discharge from refineries andfactories; runoff from landfillsand croplands

Nitrate (measuredas Nitrogen)

10 Infants below the age of sixmonths who drink water

containing nitrate in excess ofthe MCL could becomeseriously ill and, if untreated,may die. Symptoms includeshortness of breath and blue-baby syndrome.

Runoff from fertilizer use;leaching from septic tanks,

sewage; erosion of naturaldeposits

Nitrite (measuredas Nitrogen)

1 Infants below the age of sixmonths who drink watercontaining nitrite in excess ofthe MCL could becomeseriously ill and, if untreated,may die. Symptoms includeshortness of breath and blue-baby syndrome.

Runoff from fertilizer use;leaching from septic tanks,sewage; erosion of naturaldeposits

Selenium 0.05 Hair or fingernail loss;numbness in fingers or toes;circulatory problems

Discharge from petroleumrefineries; erosion of naturaldeposits; discharge frommines

Thallium 0.002 Hair loss; changes in blood;kidney, intestine, or liverproblems

Leaching from ore-processingsites; discharge fromelectronics, glass, and drugfactories

Radionuclides

Contaminant

MCL or

TT1

(mg/L)2


Ingestion of Water

Sources of Contaminant

in Drinking Water

Alpha particles 15picocuriesper Liter(pCi/L)

Increased risk of cancer Erosion of natural depositsof certain minerals that areradioactive and may emit aform of radiation known as
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alpha radiationBeta particles andphoton emitters

4milliremsper year

Increased risk of cancer Decay of natural and man-made deposits of

certain minerals that areradioactive and may emit

forms of radiation known asphotons and beta radiation

Radium 226 andRadium 228(combined)

5 pCi/L Increased risk of cancer Erosion of natural deposits

Uranium 30 ug/Las of

12/08/03

Increased risk of cancer, kidneytoxicity

Erosion of natural deposits

Notes:

1 Definitions:Maximum Contaminant Level (MCL) - The highest level of a contaminant that is allowedin drinking water. MCLs are set as close to MCLGs as feasible using the best availabletreatment technology and taking cost into consideration. MCLs are enforceable standards.

Treatment Technique - A required process intended to reduce the level of a contaminantin drinking water.

2 Units are in milligrams per liter (mg/L) unless otherwise noted. Milligrams per liter areequivalent to parts per million.

3

EPA's surface water treatment rules require systems using surface water or ground waterunder the direct influence of surface water to (1) disinfect their water, and (2) filter theirwater or meet criteria for avoiding filtration so that the following contaminants arecontrolled at the following levels:

Cryptosporidium (as of1/1/02 for systems serving >10,000 and 1/14/05 for systemsserving


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removal requirements, updated watershed control requirements for unfilteredsystems).

Filter Backwash Recycling; The Filter Backwash Recycling Rule requires systems thatrecycle to return specific recycle flows through all processes of the system's existingconventional or direct filtration system or at an alternate location approved by thestate.

4 more than 5.0% samples total coliform-positive in a month. (For water systems thatcollect fewer than 40 routine samples per month, no more than one sample can be totalcoliform-positive per month.) Every sample that has total coliform must be analyzed foreither fecal coliforms or E. coliif two consecutive TC-positive samples, and one is alsopositive for E.colifecal coliforms, system has an acute MCL violation.

5 Fecal coliform and E. coliare bacteria whose presence indicates that the water may becontaminated with human or animal wastes. Disease-causing microbes (pathogens) in thesewastes can cause diarrhea, cramps, nausea, headaches, or other symptoms. Thesepathogens may pose a special health risk for infants, young children, and people withseverely compromised immune systems.

6 Although there is no collective MCLG for this contaminant group, there are individualMCLGs for some of the individual contaminants:

Trihalomethanes: bromodichloromethane (zero); bromoform (zero);dibromochloromethane (0.06 mg/L). Chloroform is regulated with this group but hasno MCLG.

Haloacetic acids: dichloroacetic acid (zero); trichloroacetic acid (0.3 mg/L).Monochloroacetic acid, bromoacetic acid, and dibromoacetic acid are regulated withthis group but have no MCLGs.

7 MCLGs were not established before the 1986 Amendments to the Safe Drinking Water Act.

Therefore, there is no MCLG for this contaminant.8 Lead and copper are regulated by a Treatment Technique that requires systems to controlthe corrosiveness of their water. If more than 10% of tap water samples exceed the actionlevel, water systems must take additional steps. For copper, the action level is 1.3 mg/L,and for lead is 0.015 mg/L.

9 Each water system must certify, in writing, to the state (using third-party ormanufacturer's certification) that when acrylamide and epichlorohydrin are used in drinkingwater systems, the combination (or product) of dose and monomer level does not exceedthe levels specified, as follows:

Acrylamide = 0.05% dosed at 1 mg/L (or equivalent) Epichlorohydrin = 0.01% dosed at 20 mg/L (or equivalent)

National Secondary Drinking Water Regulations

National Secondary Drinking Water Regulations (NSDWRs or secondary standards) are non-enforceable guidelines regulating contaminants that may cause cosmetic effects (such as


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skin or tooth discoloration) or aesthetic effects (such as taste, odor, or color) in drinkingwater. EPA recommends secondary standards to water systems but does not requiresystems to comply. However, states may choose to adopt them as enforceable standards.

Contaminant Secondary Standard

Aluminum 0.05 to 0.2 mg/L

Chloride 250 mg/L

Color 15 (color units)

Copper 1.0 mg/L

Corrosivity noncorrosive

Fluoride 2.0 mg/L

Foaming Agents 0.5 mg/L

Iron 0.3 mg/L

Manganese 0.05 mg/L

Odor 3 threshold odor number

pH 6.5-8.5

Silver 0.10 mg/L

Sulfate 250 mg/L

Total Dissolved Solids 500 mg/L

Zinc 5 mg/L

Source: EPA 816-F-02-013

According to recent news and reports, most tap and well water in the U.S. are not safe fordrinking due to heavy industrial and environmental pollution. Toxic bacteria, chemicals andheavy metals routinely penetrate and pollute our natural water sources making people sickwhile exposing them to long term health consequences such as liver damage, cancer andother serious conditions. We have reached the point where all sources of our drinking water,including municipal water systems, wells, lakes, rivers, and even glaciers, contain somelevel of contamination. Even some brands of bottled water have been found to contain highlevels of contaminants in addition to plastics chemical leaching from the bottle.


12/22

A good water filtration system installed in your home is the only way to proactively monitorand ensure the quality and safety of your drinking water. Reverse osmosis water purificationsystems can remove 90-99% of all contaminants from city and well water to deliver healthydrinking water for you and your family

WHAT ARE THE STANDARDS FOR SAFE DRINKING WATER

It is known that no one method of filtering or purifying water is going to eliminate 100% ofelements from our drinking water. That said, water can be safe and acceptable, withinreason. There are guidelines, set by the U.S. EPA, which measure water standards to makesure our water is safe.

'Acceptable' contamination levels of water are measured by two standards: maximumcontaminant level (MCL) and maximum contaminant level goal (MCLG). For the list ofindividual contaminant standards, please click here.

The goal indicates the level of contaminant at or below which is considered safe for humanconsumption. However, given the size of most water systems, today's technological

limitations, and the costs involved with water purification, it is impossible to provide themasses with water at or below goal level for all contaminants.

Because of these difficulties, the MCL standard was created as a compromise between publicsafety and feasibility, dictating levels that must be met before water is distributed to thepublic. This level is usually within 5% of acceptable contaminant range.

Post-Filtration Contaminants

Turbidity is a measure of the cloudiness of water, and an indication of filtrationeffectiveness. Cloudy water is a sign of the presence of microorganisms that can causegastrointestinal illness. Although controlled at the original filtration source, soil runoff and

other factors can affect turbidity levels by the time water reaches a faucet.

The pipelines that transport water from its original purification source to homes andbusinesses can affect certain contaminant levels. These include: vinyl chloride, known toincrease the risk of cancer (goal level is 0; actual level is 0.02%); lead, which causes highblood pressure and kidney disease in adults and developmental delays in children (goal levelis 0; actual level is 0.015 mg/L); copper, which contributes to gastrointestinal disease in theshort-term and liver/kidney damage in the long-term (goal/actual level of 1.3 mg/L); andcadmium, known to cause kidney damage (goal/actual level of 0.005 mg/L).

Other factors can further contaminate water between its original purification andconsumption. Fertilizer runoff and leaching from septic tanks can cause increased levels of

nitrite (goal/actual level of 1 mg/L) and nitrate (goal/actual level of 10 mg/L), both of whichare lethal to infants younger than six months. Water storage tank liners leak small amountsof benzoapyrene (goal level is 0; actual level is 0.0002 mg/L), which can cause reproductivecomplications and increased cancer risk.
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The Effects of Disinfectants

Disinfectants to remove contaminants can also be harmful to humans in and of themselves.Use of disinfectants has led to the development of two additional water safety standards:maximum residual disinfectant level (MRDL) and maximum residual disinfectant level goal(MRDLG).

Just as with contaminant level standards, it is not always realistic to reach the residualdisinfectant goal. In response, the MRDL offers a balance between human safety andavailable purification resources.

Disinfectants and their byproducts found in water include bromate, known to increase therisk of developing cancer (goal level is 0; actual level is 1%) and chlorite, which can causenervous system damage in children as well as anemia (goal level is 0.8 mg/L; actual level is1.0 mg/L).

Although there is a set standard for national water safety, individual standards may vary bystate, county, and facility.

31. The Bottled Water Purification Process


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A trip to the local grocery store and a walkdown the beverage aisle will reveal dozens ofvarieties of bottled water. From big, twogallon jugs with spouts to mini bottles thatcan fit in a lunch box, there are kinds galore.But many may take for granted to process

that takes place to get that water from thesource, safely into the bottle and into ourlives.

Bottled water, often called drinking water, isusually bottled at the source and sealed insafe drinking containers. There are manytypes of bottled water, held inside many typesof unique shaped bottles. It seems the fancierthe bottle, the more expensive the waterinside. Let's take a look at the kinds of bottledwater available:

--Spring water: this comes from an underground formation and must flow naturally to theearth's surface or through a sanitary borehole.

--Purified drinking water: this type of water has been processed to remove chlorine and amajority of dissolved solids, such as magnesium. The source is not required to be namedunless it is untreated public source of water.

--Naturally sparkling water: this is naturally carbonated from a spring or artesian well.

--Seltzer Water: the FDA regulates this as a soft drink, which means rules are less strictthan those for bottled water.

--Mineral water: typically from a spring, this contains dissolved solids like calcium,magnesium, sodium, potassium, silica and bicarbonates.

Bottled water, some say, is not always safer than tap water. Tap water, from city watersystems, is monitored by the Environmental Protection Agency, while the FDA monitorswater bottling activity. In fact, bottled water is one of the products most closely monitoredby the FDA. The standards for these two agencies is a little different; for example, the EPSmonitors for asbestos while the FDA does not. Water bottlers are also not very strictlyrequired to monitor or disinfect for parasites. This is mainly because the FDA says that atthe source the water is bottled from, it is unlikely to harbor parasites or contain thesedangerous elements. However, water bottlers are given more strict standards for lead and

chlorine.

But, there is more than just the FDA. Bottled water is actually monitored at three levels toensure high quality and safety standards, the first being federal through the FDA. It is alsoregulated by the state and also by trade associations such as the International WaterBottlers Association (IBWA). While every water bottler has different techniques, here aresome general guidelines of the steps to bottling water:


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Bottling water starts at the source. As mentioned above, there are several sources to findwater: protected underground springs, wells and municipal supplies. The next step is tofilter the water through multi-barrier sources which could included source protections,source monitoring, reverse osmosis, ultraviolet light, distillation, micron filtration andozonation. Water bottlers may use one or more of those processes.

All of this must meet those federal guidelines drawn up by the FDA. These include goodmanufacturing practices, sanitary facilities and operations, quality standards, labelingstandards and quality production controls and processes. States will also regulate viainspections of both the source and the production facility, and this varies greatly from stateto state. Finally, the processes must meet industry standards, which are stricter than theFDA. Kind of a self-monitoring, if you will. The IBWA states that it maintains its own set ofstandards, where all members are subject to an annual, unannounced plant inspection by anationally recognized third-party organization. Not all water bottlers are members of thistrade organization, but more than 80% of water does come from member companies. Itmay be best to drink water from a IBWA member, as this process has three agencieswatching, rather than just two.Now that we know a little about the process and regulations,let's look at the process a little closer on specific types of water. Yes. The process is a littlemore complicated than filling a bottle and capping it. In fact, deciding to carry bottled waterrequires much insight, with two major considerations being water source and whatequipment will be used to produce it.

Source: The source of water plays a key role in the quantity and quality of water one wantsto produce, as well as to remain profitable. About a quarter of all bottled water comes frommunicipal supplies, with the rest coming from natural sources like springs and wells. But,regardless of where the water is flowing from, is privy to all the aforementioned testingfrom the agencies. One thing to take into consideration is what and organics and inorganiccompounds are present at the source, and if it is practical or not to invest in equipment toremove them.

Equipment: Who wants water that is not clear, smells funny and tastes weird? The organic

compounds, like metal ions, in water can contribute to these things. So, the processesmentioned above can help literally clear up the water. To reiterate, these are some of theprocesses: Membrane filtration can remove organic impurities, metal and other ions.Ozonization can break down organic constituents and reduce their odor potential while alsosanitizing to minimize further microbial contamination. But, whichever filtration system ischosen, the plant will be built to spec.

The two biggest selling types of bottled water are spring water and purified water. And,although the end result may taste the same, the processes of filtering are quite different.With spring water, the source must be an actual spring. The label must say so. And, thespring must be able to sustain the water production to make the choice to bottle it fromthere an economical choice. Not that would should be talking about beer in a water

informational article, but you often hear in commercials that the beer is made with waterfrom the Rocky Mountain springs. A typical spring water treatment process includes afiltration system that generally runs in series5-micron filtration to 0.2-micron filtration. Afterthe filtration process, the spring water is then usually treated with ozone to disinfect andpreserve the water in the bottle. By maintaining the nature of the spring water, ozone isconsidered to be an acceptable disinfectant. Ozone oxidizes bacteria and organic materialsand, over time, reverts back to oxygen.


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IS THE PH OF RO PERMEATE WATER LOWER THANTHE FEEDWATESR PH?

This question is answered when you understand the equilibrium relationship between CO2,

HCO3, and CO3. In a closed system, the relative amount of each of dune compounds varywith pH. At lower pH levels, CO2 is the predominant species. HCO3 is the predominantspecies at mid pH levels, and CO3 is present at higher pH levels.

Since RO membranes will reject dissolved ions and not reject dissolved gases, the ROpermeate and RO feed will contain roughly the same amount of CO 2. The HCO3 and CO3,however, are often reduced by 1-2 orders o magnitude. This upsets theCO2, HCO3, CO3 equilibrium that was established in the feed, In a series of equilibriumreactions, CO2 will combine with H2O driving reactions similar to that shown below, until anew equilibrium Is established.

CO2 + H2O --> HCO3 + H+

To summarize:

The new equilibrium will always result in a lowering of permeate pH ifthere is CO2 gaspresent in the feed water.

Usually, the pH drop is largest for waters with high amounts of alkalinity or HCO3.

When there is very little CO2, HCO3, or CO3, there is very little pH drop observed in thepermeate.

Therefore it is not true that reverse osmosis filters will always reduce the pH level of

water to a noticeable amount. The pH difference after the RO depends on the composition ofyour input water source; depends on whether you have large amounts of gases such asCO2 in your local water supply. If you are concerned with the pH of your drinking water,you should avoid guess work and get your water tested with an accurate pH tester meter(avoid those $10 paper testing strips, very inaccurate with pH readings). If you see thatyour pH is indeed below 7 with a good amount, you can consider putting a pH increaserfilter as a final stage of your reverse osmosis system and correct acid water problem easily.

Some countries have regulations governing the pH of drinking water. Typically, the pH isrecommended to be in the6.5-9.0 range. It is our understanding that the purpose of thesepH regulations are to minimize corrosion of pipingmaterials so that metals like lead andcopper do not dissolve into the drinking water supply.

Purified water is the most highly treated and closely regulated bottled water product by theFDA and IBWA, but also offers the most consistent and highest quality water to theconsumer. It is noted that consumers of bottled water prefer the taste of purified water overother types. Bottlers say the consistent flavor is a result of the purification process. Thereare three primary processes used to produce purified water: deionization, distillationand reverse osmosis. Most bottlers choose RO over the others because of the many
http://www.freedrinkingwater.com/ro-45-detail.htmhttp://www.freedrinkingwater.com/ro-45-detail.htm


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advantages, including reduced cost and increased performance. Some of these advantagesalso include removing nearly all organic compounds and up to 99% of ions and it rejects99% of viruses, bacteria and fever producing substances. Also, RO is more energy efficient.

So the next time you pick a case of water off the shelf, look closer at the label. Now thatyou have read up on the process, you can tell the difference between the identical-looking

fluids. You will know where it came from, how it was regulated, how it was purified andwhich is the safest. To bottle water at home, reverse osmosis filters can be purchased whichwill save money in the long run, as the average American spends over $300 per year onbottled water

TOTAL DISSOLVED SOLIDS IN WATER

Ionic Contaminants and Other Contaminants in Solution andSuspended Contaminants

As we learned previously, many dissolved inorganic water contaminants or impurities existas ions in solution, the most common of these ions are:

Cations Anions Calcium Ca+ + Bicarbonate HC09

Magnesium Mg++ Chloride Cl

Sodium Na+ Sulfate SO,-

Iron Fe+ + Nitrate NO,

Manganese Mn+ + Carbonate CO,_ _

These electrically charged dissolved particles make ordinary natural water a good conductorof electricity. Coversely, pure water has a high electrical resistance, and resistance isfrequently used as a measure of its purity.

Since only a few of these most common ionic water contaminants are health related, mostnatural water supplies are safe to drink from the standpoint of dissolved inorganic chemicalcontaminants. However, even though found more rarely -- and in much smaller quantities --certain inorganic ions can be toxic. These contaminants are listed, along with theirmaximum allowable levels in the summary, which also includes maximum levels forradiological ionic contaminants, maximum levels for water turbidity (cloudiness), andmaximum levels for coliform bacteria (which indicate the presence of human or animal fecalcontamination). Turbidity and bacteria are examples of suspended water contaminants.


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In addition, water supplies can contain dissolved organic chemical contaminants which areusually pollutants that enter water as a result of man's activities, such as insecticides,pesticides and herbicides. These are usually chronically, rather than acutely, toxic to manand other species in extremely small amounts. The trihalomethanes are dissolved organiccontaminants, such as chloroform, which are formed in extremely small amounts by thereaction of chlorine used to disinfect water, with humic and fulvic acids from soil erosion.

Other organics can enter both surface and groundwater through waste dumping, such astrichlorethylene, tetrachlorethylene (TCEs), polychlorinated biphenyls (PCBs), dioxin, etc.Many of the organic contaminants are probably carcinogenic (cancer-producing). Theorganics do not necessarily exist in water in the form of dissolved ions.

The Secondary Drinking Water Regulations control contaminants in drinking water thatprimarily affect the aesthetic qualities of water. Several of these -- chloride, sulfate, copper,iron, manganese, zinc, and total dissolved solids -- are ionized contaminants.

Color and odor are contaminants which cause objectionable sensory responses to the water.

pH is a measure of the acid or alkaline strength of a water supply and corrosivity refers to

the ability of a water supply to disintegrate pipes and containers

ALKALINITY OF DRINKING WATER EXPLAINED

Alkalinity of water may be due to the presence of one or more of a number of ions. Theseinclude hydroxides, carbonates and bicarbonates. As discussed in previous articles,hydroxide ions are always present in water, even if the concentration is extremely small.However, significant concentrations of hydroxides are unusual in natural water supplies, butmay be present after certain types of treatment. Small amounts of carbonates are found innatural water supplies in certain sections of the country, rarely exceeding 3 or 4 gpg. Theymay also be found in water after treatment, such as lime soda ash softening. Bicarbonatesare the most common sources of alkalinity. Almost all natural supplies have a measurableamount of this ion, ranging from 0 to about 50 gpg.

Alkalinity. The alkalinity of water may be defined as its cneutralize acid. Alkali substances in water include hydroxiThey can be detected by their acrid taste and by the fact

red litmus paper to turn blue.


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Phosphates and silicates are rarely found in natural supplies in concentrations significant inthe home. Compounds containing these ions may be used in a variety of water treatmentprocesses. Moderate concentrations of alkalinity are desirable in most water supplies tobalance the corrosive effects of acidity. However, excessive quantities cause a number ofproblems. These ions are, of course, free in the water, but have their counterpart in cationssuch as calcium, magnesium and sodium or potassium.

You probably will not notice an alkaline condition due to bicarbonate ions except whenpresent in large amounts. In contrast, you should readily detect alkalinity due even to fairlysmall amounts of carbonate and hydroxide ions.

Strongly alkaline Waters have an objectionable "soda" taste. The EPA Secondary DrinkingWater Regulations limit alkalinity only in terms of total dissolved solids (500 ppm) and tosome extent by the limitation on pH.

Highly mineralized alkaline waters also cause excessive drying of the skin due to the factthat they tend to remove normal skin oils.

Troublesome amounts of alkalinity can be removed by reverse osmosis, along with othertotal dissolved solids. Other methods of water treatment remove total dissolved solids andalkalinity, but they are somewhat less suitable for household use than reverse osmosis.These methods are distillation and deionization (demineralization).

Several other methods of water treatment will remove alkalinity, but these methods are notsatisfactory for household use. They include:

1. Lime softening removes hardness. At the same time, this process will precipitate anequivalent amount of alkalinity. Lime softening is usually restricted to industrial andmunicipal installations.

Lime softening. While reducing total alkalinity, lime softening does convert HC03

to CO3--,a stronger alkalinity ion.

2. An anion resin regenerated with sodium chloride removes substantially all the anions(carbonates, bicarbonates, and sulfates, as well as nitrates). It replaces these anions with achemically equivalent amount of chloride ions. The disadvantage of this process is that inalmost all cases a high chloride ion concentration results. At the point of exhaustion, theresin has the tendency to unload high concentrations of the anions it carries including thenitrates. For household purposes, such results are almost as undesirable as the originalalkalinity.

3. The feed of a mineral acid will neutralize the alkalinity of a water. Hydrochloric acid,sulfuric acid or a combination of these can be used. This process converts the bicarbonatesand carbonates present into carbonic acid. At this point, it is advisable to provide somemethod to permit the resulting carbon dioxide gas to escape into the atmosphere. Thedisadvantages of this acid feed technique are obvious. There are needs for precise control ofthe process and caution in handling the strong acid.


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DRINKING WATER CONTAMINANTS AND THEIR CONTROLWITH REVERSE OSMOSIS WATER TREATMENT

Nominal Rejection Performance for Reverse Osmosis Membranesat 60 psi Net Pressure and 77 F.1

TFC* typemembraneRejection

SodiumCalciumMagnesiumPotassiumIron 2Manganese 2AluminumCopperNickel

ZincStrontiumCadmiumSilverMercuryBariumChromium-6Chromium-3LeadChlorideBicarbonateNitrate3FluoridePhosphateChromateCyanideSulfateBoronArsenic + 3Arsenic + 5SeleniumRadioactivity-----------

Bacteria

ProtozoaAmeobic- CystsGiardiaAsbestosSediment/Turbidity

OrganicContaminants

90-95%93-98%93-98%90-95%93 98%93-98%93-98%94-99%93-98%

93-98%93-98%93-98%93-98%93-98%93-98%94-99%94-99%94-99%90-95%90-95%85-90%90-97%93-98%90-95%90-95%93-98%55-60%70-80%94-99%93-98%93-98%--------

> 99%

> 99%> 99%

> 99%> 99%> 99%> 99%

1. This table of nominal rejection performance is for reverseosmosis membranes used in drinking water systems operating ata net pressure (feed pressure less back pressure and osmoticpressure) of 60 psi and 77 F water temperature.

The actual performance of systems incorporating thesemembranes may be different due to changes in feed pressure,temperature, water chemistry. contaminant level, net pressure onmembrane, and individual membrane efficiency. Countertop RO

drinking water systems produce better overall rejectionperformance than undercounter systems due to maximizing of netpressure on membrane.

2. While iron and manganese are effectively removed by themembrane, they also can easily foul its surface with deposits evenat low concentrations. Generally, iron and manganese should beremoved by other water treatment methods prior to ROtreatment.

3. Nitrate removal depends on factors such as pH, temperature,net pressure across membrane. and other contaminants present.


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Organicmolecules witha molecularweight < 300

> 99%

*TFC-Thin Film Composite MembraneThis information is extracted from the Water Quality Association WQA.

What is ultrafiltration (UF) in terms of membrane filter technology?

Ultrafiltration (UF) is a variety of membrane filtration in which hydrostatic pressure forces aliquid against a semipermeable membrane. Suspended solids and solutes of high molecularweight are retained, while water and low molecular weight solutes pass through themembrane. This separation process is used in industry and research for purifying andconcentrating macromolecular (103 - 106 Da) solutions, especially protein solutions.Ultrafiltration is not fundamentally different from reverse osmosis, microfiltration ornanofiltration, except in terms of the size of the molecules it retains.

A membrane or, more properly, a semipermeable membrane, is a thin layer of materialcapable of separating substances when a driving force is applied across the membrane.Once considered a viable technology only for desalination, membrane processes areincreasingly employed for removal of bacteria and other microorganisms, particulatematerial, and natural organic material, which can impart color, tastes, and odors to thewater and react with disinfectants to form disinfection byproducts (DBP). As advancements

are made in membrane production and module design, capital and operating costs continueto decline. The pressure-driven membrane processes discussed in this fact sheet aremicrofiltration (MF), ultrafiltration (UF), nanofiltration (NF), and reverse osmosis (RO).

The primary advantages of low-pressure UF membrane processes compared withconventional clarification and disinfection (postchlorination) processes are:

No need for chemicals (coagulants, flocculates, disinfectants, pH adjustment); Size-exclusion filtration as opposed to media depth filtration; Good and constant quality of the treated water in terms of particle and microbialremoval; Process and plant compactness; and

Simple automation.Ultrafiltration (UF) is used to remove essentially all colloidal particles (0.01 to 1.0 microns)from water and some of the largest dissolved contaminants. The pore size in a UFmembrane is mainly responsible for determining the type and size of contaminantsremoved. In general, membrane pores range in size from 0.005 to 0.1 micron. UFmembrane manufacturers classify each UF product as having a specific molecular weightcutoff (MWC), which is a rough measurement of the size of contaminants removed by agiven UF membrane. A 100,000 MWC UF membrane means that when water containing a


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given standard compound with a molecular weight of around 100,000 daltons is fed to theUF unit, nearly all of the compound will not pass through the membrane.

Substances with a molecular weight of 100,000 daltons have a size of about 0.05 microns toabout 0.08 microns in diameter. UF membranes are used where essentially all colloidalparticles (including most pathogenic organisms) must be removed, but most of the

dissolved solids may pass through the membrane without causing problems downstream orin the finished water. UF will remove most turbidity from water.

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Common Water Quality Problems and Their Methods of Treatment

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