Water & Health Newsletter
Table of Contents
Consumers have decisions to make
Put yourself in the position of an average consumer shopping for a water treatment system at any home supply store. Shelves of different devices, varied prices and product promises are enough to boggle even knowledgeable buyers. Imagine making a purchase without knowing what you need or how to make a smart choice - you can understand the confusion most consumers feel.
In spite of confusion, many consumers are buying home water treatment devices. Their interest may be fueled as much by fear as actual need. Periodic media reports of contaminated water are causing many people to doubt the quality of their drinking water. The sudden proliferation of products on store shelves seems to confirm their doubts. At the same time, regulatory and legislative actions surrounding drinking water standards are raising consumer awareness and questions. For many consumers concerned about their drinking water, buying a home water treatment device appears to be an easy solution. That is, until they find themselves faced with a wall of choices.
One dilemma consumers face is whether they actually need a home treatment device. Chlorine is widely used as a drinking water disinfectant by public water treatment facilities across the country and while an effective protection against microbial diseases, it does not remove heavy metals. And in some instances, chlorinated water has a noticeable taste or odor. Consumers may choose to purchase home treatment devices to eliminate heavy metals and the taste or odor from chlorinated water.
"What's in my drinking water?"
Typically, consumers shopping for a "water purifier" start by looking in the wrong place. The store is the last stop they should make. The search should begin at home with a test to determine what's in their drinking water. A laboratory analysis can specify what, if any, contaminants are in the water. It also can identify the source of undesirable color, taste or odor.
To find a reliable testing laboratory, consumers should contact their local water treatment facility or public health department. Additionally, the U.S. Environmental Protection Agency's (EPA's) Safe Drinking Water Hotline. (800) 426-4791 can give information on contaminant testing services available in your state.
Finding the answer to the most important question. "What's in my drinking water?", will help consumers know what to look for in the store.
The right device for the job
Not all home water treatment devices solve all drinking water problems. Some devices are designed to remove impurities that others don't touch. Consumers who have decided to buy a water purifier should look for devices that are designed to remove specific impurities in their drinking water.
Of the products available, many are designed for point of usage (POU) and are to be installed at the taps primarily used for drinking and cooking water. Other systems, for point of entry (POE), may be installed at the home's water main and remove contaminants throughout the home's water system. Regardless of installation site, types of devices and capabilities range widely. Some of the most common types of water treatment devices currently on the market are described below. For a summary of what kinds of contaminants each device is designed to remove. see the chart below.
Carbon or charcoal filters remove some organic chemicals and reduce undesirable tastes, odors or color. They also remove some pesticides and inorganic chemicals. Carbon filters don't remove heavy metals such as lead, copper or mercury. Filters must be changed regularly or contaminants may be "filtered" right back into the drinking water. To avoid health risk, these devices should be used to treat water that is already microbiologically safe or of known quality.
There are two types of water softeners: cation and anion exchange units. Cation softeners eliminate hard water problems, removing calcium, magnesium, iron and manganese ion. Anion softeners work to remove sulfates, nitrates, bicarbonates and chlorides. Both types replace minerals with sodium - something consumers on sodium-restricted diets should consider before purchasing. In addition, consumers should be aware that they will also be losing the benefits of important minerals.
Water distillation units remove heavy metals as well as minerals that cause hard water This process kills microorganisms and separates the contaminants from the distilled drinking water.
Reverse osmosis (RO) devices can remove dissolved salts, heavy metals. bacteria and some organics - depending on the type of membrane used to filter the water. This type of device is not recommended for treating water containing hardness minerals or high amounts of suspended solids. Some RO devices include a carbon filter to reduce organic chemicals.
Consumers should check the manufacturers' recommendations and guidelines for maintenance before purchasing. Most home water treatment devices require some upkeep to ensure continued effectiveness. For an extra measure of confidence in product performance. consumers should shop for devices that have been certified by the National Sanitation Foundation (NSF). The NSF mark certifies that the device has been thoroughly tested and meets product claims. And if you want to know if the manufacturer meets quality guidelines and sound business practices. contact the Water Quality Association at (708) 505-0160.
Making a smart choice
The only way for consumers to be sure they get the right home water treatment device to correct their problems is to determine what problems need to be solved Without a thorough analysis of their drinking water, buying a product that claims to make it completely safe can be risky business.
Susan Seacrest, President, The Groundwater Foundation
Hidden beneath the land surface in almost every part of the United States are natural reservoirs of a precious commodity - groundwater. The importance of groundwater to the United States is aptly demonstrated by a few statistics. Groundwater provides:
While it is easy to recognize the importance of groundwater, by its very location, groundwater remains a mystery to many. Despite much available information, groundwater's existence, movement, quantity and quality often are misunderstood. As a result, groundwater too often is taken for granted. It is threatened by contamination from human sources in residential, industrial and agricultural areas, as well as by natural sources found in the environment.
Such contamination raises public health concerns because of threats to drinking water safety. Groundwater contaminated with bacteria, chemicals, gasoline or oil can result in serious health problems. Those who drink it, or come in contact with it, can get bacterial disease, nervous system disorders, liver or kidney failure or cancer.
It is critical that those responsible for protecting the nation's public health understand how groundwater is contaminated, what is being done to control or limit contamination and what steps can be taken at the community level to protect this important resource.
Sources of groundwater contamination
Because we have not understood the characteristics of groundwater, or how vulnerable it is, society has been careless. Gasoline and other harmful liquids have been allowed to leak from underground storage tanks into the groundwater supply. Pollutants from poorly constructed landfills and septic systems also have escaped into groundwater resources. Groundwater also can be polluted by runoff from fertilized fields, livestock areas. salted roads and industrial areas. Homeowners can contribute to groundwater contamination by dumping household products down the drain or pouring them on the ground.
Although many people believe that human activities are the major source of groundwater quality degradation, numerous studies suggest that naturally occurring contaminants contribute greatly to this problem. Naturally occurring contaminants that can leach into aquifers include nitrate, selenium, iron, silica, sodium, potassium, fluoride boron. mineral salts. radioactive materials and toxic substances.
While contaminated groundwater can be cleaned up., it is a time-consuming, expensive and difficult task. Because cleanup activities can result in doubling or tripling the cost of drinking water. it is far better to prevent contamination in the first place. Indeed, the U.S. Environmental Protection Agency (EPA) has called pollution prevention the only viable strategy for effectively maintaining groundwater quality.
In 1986, Congress created the EPA Wellhead Protection (WHP) program. an efficient and cost-effective measure to protect groundwater, in the Safe Drinking Water Act (SDWA) amendments. The purpose of the program is to protect groundwater supplies from contamination and prevent the need for costly treatment in order to meet drinking water standards. This is accomplished primarily through the application of land-use management practices and other preventive measures. Under the SDWA, states are encouraged to develop and submit wellhead protection programs to the EPA.
Wellhead protection is very affordable compared to cleaning up groundwater. A Superfund cleanup project can cost millions of dollars. On the other hand, if technical support and planning guidance are available, a wellhead protection program can be fully implemented for as little as $5,000 to $l0,000. EPA demonstration grants have shown wellhead protection to be an effective measure for protecting groundwater resources.
As part of the current SDWA reauthorization process. the EPA has proposed expanding the WHP program to include both surface and groundwater in a source water protection (SWP) program for drinking water.
Source water protection
As proposed. the SWP would continue to emphasize contamination prevention. Specifically, the program would mandate state-level delineation of drinking water sources, an inventory of potential contamination sources, and local programs to develop and enforce controls on contamination sources.
The EPA, in conjunction with the states. has used existing statutory authority under the SDWA to move its drinking water regulatory programs strongly in the source water protection area.
What can he done to protect groundwater resources?
While there is a definite role for federal involvement, groundwater protection is most effective at the local level. Public health professionals should educate their communities about the many things that can be done to protect groundwater:
Other local efforts include joint ventures between the U.S. EPA and the League of Women Voters. the Retired Senior Volunteer Program, and the Environmental Alliance for Senior Involvement.
Groundwater contamination is a serious problem. Public health professionals can play an important role in the protection of this valuable resource by understanding how it is contaminated and what can be done to safeguard groundwater supplies.
Two long-awaited drinking water rules have been released for public comment by the U.S. Environmental Protection Agency (EPA): the Disinfectants/Disinfection By-Products Rule and the Enhanced Surface Water Treatment Rule.
The proposed Disinfectant/Disinfection By-Products Rule sets new maximum allowable concentrations for chemical disinfectants. including chlorine, chlorine dioxide and chloramines. In addition, the rule sets stringent new standards for chlorination by-products and adds haloacetic acids to the list of regulated compounds. The rule also sets new limits for chlorite and bromate, byproducts from the use of chlorine dioxide and ozone, respectively.
The proposed Enhanced Surface Water Treatment Rule (ESWTR) is targeted at protecting water systems from harmful protozoa, such as giardia and cryptosporidium, and viruses. The rule would require systems with poorer source water to provide greater control than is required under the existing surface water treatment regulation. A sanitary survey will be required every five years so that the water systems can check the effectiveness of their operations. The rule would apply to those systems serving more than 10,000 people. However, the sanitary survey would apply to those systems serving fewer than 10,000. as well.
Both regulations would present a significant increase in monitoring requirements for water utilities. The rules also would have a significant economic impact on utilities and their customers. The EPA has indicated that the utilities would have to spend about $4.4 billion on plants and equipment to comply with the first phase of the Disinfectant/Disinfection By-Products rule alone.
The public comment period for both proposed rules ends Dec. 29, 1994. The editorial board of Drinking Water & Health encourages all of its readers to study these rules and submit comments to the EPA. For information on submitting comments, contact the EPA's Safe Drinking Water Hotline at (800) 426-4791. or read the Federal Register notice of July 29. Information also is available through Joe Walker at the Chlorine Chemistry Council, (202) 887-5412.
Despite a flurry of last minute negotiations, the House and Senate failed to adopt new laws affecting the nation's drinking water prior to adjournment on Oct. 8. The long-delayed House bill (H.R. 3392) was passed Sept. 27, leaving only two weeks to blend the House and Senate bills. The Senate had passed its reauthorization bill (S. 2019) in May.
Since the beginning of the reauthorization process, polarized positions on issues around risk assessment, unfunded mandates and private property takings proved to be insurmountable obstacles to a bill acceptable to all parties. Amendments addressing each of these issues were included in S. 2019. While Senate negotiators reportedly did go along with the House language on standard setting, they held out to keep their EPA-wide risk and property takings amendments in the bill.
Adding to the pressure, environmental groups promised to oppose a bill that included any provisions from the Senate effort that would "weaken" the current rule.
Efforts to revise the legislation are likely early next year.
The U.S. Environmental Protection Agency (EPA) in 1992 and 1993 conducted a regulatory negotiation to develop a consensus-based regulation for disinfectants and disinfection byproducts (D/DBP) Three drinking water rules came out of the negotiations: 1) the D/DBP Rule, 2) the Enhanced Surface Water Treatment Rule (ESWTR) and 3) the Information Collection Rule (ICR). The ICR was the first of these rules to be proposed and published in the Federal Register, appearing on Feb. 10, 1994.
Because of the limitations of the scientific data on D/DBPs and microbial pathogens, the EPA decided to propose a two-stage D/DBP rule. Consequently. the purpose of the ICR is to gather scientific information on the occurrence and treatability of DBPs for a second regulation negotiation to be held in 1998 and the development of the ESWTR in 1996-1997. Large systems will be required to start ICR monitoring in October 1994, and all testing is to be completed by 1997.
Utilities that treat surface or groundwater may be required to monitor for microbial pathogens. DBPs and DBP precursors. They also may be required to perform a study on the use of DBP precursor removal technologies, depending on various; population cutoffs and the type of water treated. Nationwide. the ICR is estimated to cost $130 million. This article will focus on the DBP monitoring requirements.
Looking at the Specifics
Under the ICR, all systems that treat surface or groundwater and serve 100,000 people or more will be required to monitor for DBPs (see Tables 1 and 2). DBP precursors and other water-quality parameters over an 18-month period. Groundwater systems that serve 50,000 to 100,000 people will be required to monitor for total organic carbon (TOC), but not DBPs.
Currently, trihalomethanes (THMs) are the only DBPs for which there is an existing laboratory certification program. Because the ICR is slated to begin shortly. the EPA will be setting up a process to "approve" laboratories to perform analyses for the ICR. The agency has prepared a guidance manual on analytical methods for DBPs and other chemicals to be monitored for in the ICR. The public can call the EPA Water Resource Center in Washington. D.C., at (800) 426-4791 to obtain a copy of the guidance manual.
Table 3 lists the ICR analytical methods for DBPs. along with their approximate unit cost. A single sample can be extracted with pentane or tertiary-butyl methyl ether (tbme) and analyzed on a capillary column gas chromatograph (GC), equipped with an electron capture detector (ECD), for four THMs. four haloacetonitriles (HANs), two haloketones (HKs), and chloropicrin (CP). A separate extraction with tbme can be analyzed on a GC/ECD for chloral hydrate. THMs may be analyzed with chloral hydrate, but because of the need for different dechlorination agents or preservatives, the HANs, HKs and CP must be done separately from chloral hydrate.
There will be additional monitoring requirements for those systems that use alternative disinfectants to chlorine. Aldehydes - which are produced by ozone and. to a lesser extent, by chlorine dioxide - require derivatization with O-(2,3,4,5,6-pentafluorobenzyl)-hydroxylarnine (PFBHA), extraction with hexane and GC/ECD analysis. A draft standard method for aldehydes is provided in the guidance manual. Cyanogen chloride (CNCl) which is preferentially formed in systems using chloramines - can be analyzed by a purge-and-trap GC/mass spectrometer (MS) method. Bromate - which also is produced by ozone and possibly by chlorine dioxide under certain conditions - is analyzed by ion chromatography ('C). IC also will be required for the analysis of chlorite and chlorate, both of which are by-products of chlorine dioxide; chlorate also is associated with systems that chlorinate with hypochlorite ion solutions.
Preparing for the future
Laboratories that would like to become approved to run analyses for the ICR for chemicals that arc not covered under other drinking water regulations must register with the U.S. EPA. The guidance manual includes sample registration forms and information about the approval process, which includes an initial demonstration of analytical capability as well as ongoing quality assurance/quality control (QA/QC) requirements. A laboratory may apply for approval for selected methods. For more information, contact: U.S. EPA, Office of Groundwater and Drinking Water, Technical Support Division, Attn: DBP/ICR Analytical Methods Guidance Manual, 26 W. Martin Luther King Dr., Cincinnati, OH 45268.
For laboratories looking further to the future, the draft D/DBP Rule will have monitoring requirements for THMs, HAAs. bromate and chlorite. In addition, some ozone systems may need to monitor for aldehydes as part of complying with a treatment performance requirement where biological filtration must be demonstrated.
The data from the ICR will ensure that the development of Stage 2 of the D/DBP Rule and the ESWTR will be based on sound science. This is critical given the potentially enormous investments necessary to comply with these regulations.
Drinking Water & Health Newsletter is a Publication of the Public Health Advisory Board to the Chlorine Chemistry Division of the American Chemistry Council
Public Health Advisory Board
M. Brown, Jr.
K. Bernard, PH.D.
Chemistry Division of the American Chemistry Council
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