Common Drinking Water Contaminates

By the The Natural Resources Defense Council, Part 2.

Contanimation health effects, treatments, and recommendations for associated United States cities.

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NRDC’s review of city tap water quality revealed that there are several contaminants that occur with surprising regularity in tap water throughout America’s cities, regardless of location—such as chlorination by-products, lead, and total coliform bacteria. Other contaminants, such as industrial chemicals, may occurless frequently but still pose major health concerns. This chapter summarizes thehealth concerns for and sources of many of the most common tap water contaminants.

Haloacetic Acids (HAAs)/Total Trihalomethanes (TTHMs)

HAAs National Standard (MCL)
60 ppb (average) (effective 2002; no previous standard)
HAAs National Health Goal (MCLG)
0—no known fully safe level103
TTHMs National Standard (MCL)
80 ppb (average) (effective 2002)
100 ppb (average) (effective through 2001)
TTHMs National Health Goal (MCLG)
0—no known fully safe level104 HAAs

HIGH CONCERN
ATLANTA
BALTIMORE
BOSTON
HOUSTON
LOS ANGELES
NEWARK
PHILADELPHIA
SAN DIEGO
WASHINGTON, D.C.

SOME CONCERN
ALBUQUERQUE
CHICAGO
DETROIT
MANCHESTER
NEW ORLEANS
Phoenix
SAN FRANCISCO
SEATTLE

LITTLE OR NO CONCERN
CHICAGO
DENVER TTHMs
VIOLATION
SAN FRANCISCO
HIGH CONCERN
BOSTON
HOUSTON
LOS ANGELES
MANCHESTER
NEWARK
PHILADELPHIA
Phoenix
SAN DIEGO
SEATTLE
WASHINGTON, D.C.
SOME CONCERN
ALBUQUERQUE
ATLANTA
BALTIMORE
DENVER
DETROIT
NEW ORLEANS
LITTLE OR NO CONCERN
CHICAGO
FRESNO

Total trihalomethanes (TTHMs) and haloacetic acids (HAAs) are volatile organic contaminants often referred to as disinfection by-products, or DBPs. TTHMs and HAAs are chemical contaminants that result when chlorine used to disinfect drinking water interacts with organic matter in the water. TTHMs consist of a sum of the levels of four closely related chemicals—chloroform, dibromochloromethane, bromoform, and bromodichloromethane—which occur together at varying ratios when water is chlorinated. HAAs regulated by the EPA include five related chemicals: monochloroacetic acid, dichloroacetic acid, trichloracetic acid, monobromoacetic acid, and dibromoacetic acid. TTHMs are used as an indicator of a complex soup of other potentially risky DBPs or "chlorination by-products."

Health Effects

More than a dozen epidemiological studies of people who drank water containing chlorination by-products have linked the chemicals to bladder cancer, and several studies indicate likely links to colorectal, pancreatic, and other cancers.105 National Cancer Institute epidemiologists found links to brain cancer recently, and a link to childhood leukemia has been noted in a recent Canadian epidemiological study.106,107 The EPA has classified some individual TTHMs as probable human carcinogens. Recent studies have also found that some pregnant women exposed to DBPs in tap water may have a higher risk of problems with their babies, even after relatively brief periods of exposure to spikes of the chemicals. The most significant concerns raised by studies of pregnant women have been about findings of associations between elevated levels of chlorination by-products (including TTHMs) and low birth weight, preterm delivery, spontaneous abortions (miscarriages), stillbirths, and birth defects (central nervous system, major cardiac, oral cleft, respiratory, and neural tube defects).108 For example, one study in California found a significant association between women who drank more than six glasses of water a day containing more than 75 ppb TTHMs and miscarriages by those women.109 Lab studies on animals and studies of pregnant women exposed to chlorination by-products have also found an association between TTHMs and low birth weight.110 The evidence that chlorination by-products cause miscarriages, birth defects, low birth weight, or other reproductive problems is not conclusive but raises major concerns worthy of preventative action to reduce or eliminate exposure to these chemicals. As one recent scientific review concluded, several studies have "shown associations for DBPs and other outcomes such as spontaneous abortions, stillbirth, and birth defects, and although the evidence for these associations is weaker, it is gaining weight."111 Treatment and Standard
Two TTHMs (bromoform and bromodichloromethane) and dichloroacetic acid have health goals of 0 because of cancer risks. In addition, the EPA promulgated and then withdrew after a court decision a 0 health goal for chloroform. It has not yet issued a new goal for chloroform. Since water systems generally report only the combined TTHM level, and since it is essentially chemically impossible to create one trihalomethane or one haloacetic acid in tap water without some level of the others, NRDC lists the health goal for TTHMs and HAAs as 0. In 1979, the EPA announced an "interim" tap water standard for TTHMs of 100 ppb that allows systems to test across their distribution systems every quarter, averaging the levels across time and across the distribution system, and that exempts systems serving fewer than 10,000 people.112 After complaints that the interim standard was too lax, the EPA said it would promptly review it. After many years of debate, and a 1994 agreement in a regulatory negotiation among the EPA, the water industry, NRDC, other health and consumer groups, states, and others, the EPA agreed to issue a "Stage 1 DBP Rule" that would strengthen the standard to 80 ppb and set a 60 ppb standard for HAAs.113 The EPA published the final rule embodying that agreement in 1998. The EPA also agreed in the regulatory negotiations to propose a reduction to 40 ppb TTHMs and 30 ppb HAAs as a "Stage 2 DBP Rule," which is legally overdue.114 Following a subsequent regulatory negotiation among most of the same parties, the EPA agreed to rework how the standards would be measured, putting much more emphasis on reducing peak TTHM and HAA levels, due to concerns about reproductive hazards, but left the actual MCL numbers in place.115 The new standard would have the effect of substantially reducing the highest peaks in DBPs, and would also, the technical experts agreed, substantially reduce the average levels of DBPs in those systems, smoothing out their peak levels.116 The EPA has missed the deadline for issuing that new standard, and in fact has not even published the proposal in The Federal Register.

Hexachlorocyclopentadiene (HEX)

National Standard (MCL)
50 ppb (average)
National Health Goal (MCLG)
50 ppb HEX
LITTLE OR NO CONCERN
PHILADELPHIA Hexachlorocyclopentadiene is an industrial chemical used to make other
chemicals, including pesticides, flame retardants, resins, dyes, pharmaceuticals, and plastics.117

Health Effects

According to the EPA, short-term exposure to high levels of HEX causes gastrointestinal distress and liver, kidney, and heart damage. Prolonged exposure, again according to the EPA, has the potential to cause long-term damage to the stomach and kidneys.118Treatment and Standard
HEX can be removed from tap water with granular activated carbon combined with packed tower aeration or by reverse osmosis. Methyl Tertiary-Butyl Ether (MTBE)
National Standard (MCL)
None
National Health Goal (MCLG)
NoneMTBE
SOME CONCERN
MANCHESTER
LITTLE OR NO CONCERN
SAN DIEGOEPA Health Advisory 20–40 ppb (based on taste and odor concerns; the EPA says safe health level is higher) MTBE is a fuel additive, commonly used in the United States to reduce carbon monoxide and ozone levels caused by auto emissions119 Because of its widespread use, reports of MTBE detections in the nation’s groundwater and surface water supplies are increasing.120 MTBE gets into water supplies from leaking underground or aboveground storage tanks, spills, pipeline leaks, refineries, inefficient boat and other watercraft engines, runoff from streets, and even atmospheric deposition.121Health Effects

For several years running, the EPA has maintained that it is currently studying the implications of setting a drinking water standard for MTBE. There are numerous animal studies showing possible cancer and other adverse health effects of MTBE.122Treatment and Standard
The EPA has yet to make a commitment to issue a standard and has not promised to make a decision on a standard at any specific date. The EPA says that concentrations in the range of 20 to 40 micrograms per liter (or ppb) are the most people can tolerate because of the very bad turpentine-like or gasoline-like taste and odor of the water.123 The health effects of these low levels are uncertain, according to the agency, since the limited testing of the chemical has shown that the taste and odor threshold "is lower than the range of exposure levels in which cancer or noncancer effects were observed in animal tests, though low doses may pose a cancer risk."124

Pentachlorophenol (Penta)

National Standard (MCL)
1 ppb (average)
National Health Goal (MCLG)
0—no known fully safe level
Pentachlorophenol is a common preservative used on telephone poles, railroad
ties, and other wood.125 PENTA
SOME CONCERN
PHILADELPHIA Pentachlorophenol is a common preservative used on telephone poles, railroad
ties, and other wood.125 Health Effects

The EPA reports that short-term exposure to high levels may cause central nervous system problems, while long-term exposure has the potential to cause reproductive problems and damage to liver and kidneys, in addition to cancer.126 Treatment and Standard
Penta can be removed from tap water with granular activated carbon or reverse osmosis. Because it is a probable carcinogen, the health goal for penta is 0.127

Simazine

National Standard (MCL)
4 ppb (average)National Health Goal (MCLG)
4 ppb SIMAZINE
SOME CONCERN
PHILADELPHIA A chemical cousin of atrazine, simazine is widely used in agriculture as a preemergence
herbicide for control of broad-leaved and grassy weeds.128 Its major use is on corn, where it is often combined with atrazine.129 It is also used on a variety of deep-rooted crops, including artichokes, asparagus, berries, broad beans, and citrus, and on noncrop areas such as farm ponds and fish hatcheries.130 Health Effects
The EPA says that high levels of simazine exposure over a short term can cause weight loss and changes in blood. The EPA determined in 2002 that the chemical cousins triazine pesticides—simazine, atrazine, and propazine, as well as several of their degradates—all share a "common mechanism of toxicity," which is to say that they all poison the body the same way131 Treatment and Standard
The EPA says that prolonged exposure to elevated levels of simazine above the MCL have the potential to cause tremors; damage to the testes, kidneys, liver, and thyroid; gene mutations; and cancer.132 The EPA has yet to take action to reduce the allowable levels of simazine in tap water or elsewhere. Simazine can be removed from tap water with granular activated carbon or reverse osmosis.

Tetrachloroethylene (Also Called Perchloroethylene, PCE, or PERC)

National Standard (MCL)
5 ppb (average)
National Health Goal (MCLG)
0—no known fully safe level PERC
SOME CONCERN
FRESNO Tetrachloroethylene is used in dry cleaning and industrial metal cleaning or finishing.133 It enters the water system via spills or releases from dry cleaners or industrial users, waste dumps, leaching from vinyl liners in some types of pipelines used for water distribution, and in some cases during chlorination water treatment.134 Health Effects
Prolonged consumption of water contaminated by PERC can cause liver problems and may cause cancer.135 Treatment and Standard
PERC can be removed from tap water with granular activated carbon in combination with packed tower aeration.

Toluene

National Standard (MCL)
1 ppm (1,000 ppb) (average) National Health Goal (MCLG)
1 ppm (1,000 ppb) TOLUENE
SOME CONCERN
PHILADELPHIA Toluene is a volatile organic chemical with a sweet odor.136 A component of
gasoline and other petroleum fuels, it is used to produce benzene and urethane, as
well as in solvents and thinners, and is released in wastewaters or by spills on land
during the storage, transport, and disposal of fuels and oils.137 According to the EPA’s
Toxic Chemical Release Inventory, toluene releases to land and water totaled more than 4 million pounds from 1987 to 1993, primarily from petroleum refining.138 Health Effects
Short-term exposure to toluene at high doses can cause minor nervous system disorders such as fatigue, nausea, weakness, and confusion.139 Longer-term exposure to lower levels (but over the MCL) can cause more pronounced nervous disorders such as spasms, tremors, liver and kidney damage, and impairment of speech, hearing, vision, memory, and coordination.140 Treatment and Standard
Toluene can be removed from tap water with granular activated carbon in combination with packed tower aeration.

Trichloroethylene (TCE)

National Standard (MCL)
5 ppb (average)
National Health Goal (MCLG)
0—no known fully safe level TCE
SOME CONCERN
FRESNO
MANCHESTER Trichloroethylene (TCE) is a colorless liquid used as a solvent to remove grease
from metal parts. It is present in many underground water sources and surface waters as a result of the manufacture, use, and disposal of TCE at industrial facilities across the nation.141 Health Effects
TCE is a likely carcinogen, and people exposed to high levels of trichloroethylene in
their drinking water may experience harmful effects to their nervous system, liver
and lung damage, abnormal heartbeat, coma, and possibly death.142 Treatment and Standard

TCE can be removed from tap water with granular activated carbon in combination
with packed tower aeration.

Vinyl Chloride

National Standard (MCL)
2 ppb (average)National Health Goal (MCLG)
0—no known fully safe level VINYL CHLORIDE
HIGH CONCERN
PHILADELPHIA Vinyl chloride is used in the manufacture of cars, electrical wire insulation and
cables, piping, industrial and household equipment, and medical supplies, and is
also heavily used by the rubber, paper, and glass industries.143 Health Effects

Long-term exposure, according to the EPA, can cause cancer and liver and nervous
system damage.144 Treatment and Standard

Vinyl chloride can be removed from drinking water with granular activated carbon in
combination with packed tower aeration, or by reverse osmosis. The EPA has found
that relatively short-term exposure to vinyl chloride at levels above the current
standard of 2 ppb potentially causes damage to the nervous system.

RADIOACTIVE CONTAMINANTS

Gross Alpha Radiation

National Standard (MCL)
15 pCi/L (average)
National Health Goal (MCLG)
0—no known fully safe level GROSS ALPHA
RADIATION
SOME CONCERN
ALBUQUERQUE
FRESNO
LOS ANGELES
SAN DIEGO
WASHINGTON, D.C. Alpha particle radiation generally results from the decay of radioactive minerals in
underground rocks and is sometimes a by-product of the mining or nuclear industries. Health Effects

Alpha particle radiation causes cancer.145 Treatment and Standard

The best available treatment for alpha emitters other than radon or uranium is reverse
osmosis membrane filtration (RO).146 The RO membrane removes virtually all contaminants,
including Crypto and other microbes, most industrial or agricultural
synthetic chemicals, radioactive contaminants, and even most inorganic contaminants,
including arsenic. The resulting water is almost entirely pure.

Gross Beta Radiation

National Standard (MCL)
50 pCi/L (average)
National Health Goal (MCLG)
0—no known fully safe level GROSS BETA
RADIATION
SOME CONCERN
LOS ANGELES
SAN DIEGO
WASHINGTON, D.C. Beta particle and photon emitter radiation generally results from the decay of
radioactive minerals in underground rocks and is sometimes a by-product of nuclear
testing or the nuclear industry. Health Effects

Beta particle and photon emitter radiation causes cancer.147 Treatment and Standard

The best available technologies for removing beta radiation or photon emitters is ion
exchange or reverse osmosis (RO). As noted above, RO removes virtually all other
contaminants as well.

Radon

National Standard (MCL) (proposed)
300 pCi/L (averages)
alternate MCL of 4,000 pCi/L where approved multimedia program is in place (average)
National Health Goal (MCLG) (proposed)
0—no known fully safe level RADON
VIOLATION
(PROPOSED STANDARD)
ALBUQUERQUE
HOUSTON
FRESNO
HIGH CONCERN
LOS ANGELES Radon is a radioactive gas that results from the natural radioactive breakdown of uranium in the ground. Communities that depend on groundwater can often encounter radon gas in their drinking water, and in the United States, more than 81 million people’s drinking water comes from groundwater. Health Effects

Radon is known to cause lung cancer. No amount of it is considered fully safe in tap water; indeed, a single particle of radon can cause cancer.148 The EPA estimates that radon in drinking water causes approximately 168 deaths from lung and stomach cancers each year—89 percent from lung cancer caused by breathing radon released to the indoor air from water and 11 percent from stomach cancer caused by consuming water that contains radon.149 In fact, radon is the second leading cause of lung cancer deaths in the United States after smoking, causing what the NAS has estimated is a total of 20,000 lung cancer deaths per year. Most of these lung cancers are due to radon seepage from soil into basements and through floor slabs, underscoring the importance of radon testing for basements.150 But radon in tap water is a threat as well. Treatment and Standard

Radon is easily removed from tap water through simple aeration of the water— bubbling air through water in a packed tower. The EPA’s estimated cost per household for customers living in a big city for this simple but life-preserving step: $9.50 per year.151
Some water industry representatives argue that since more people die from basement seepage of radon, worries about radon in tap water are misplaced. Congress relied on this argument in establishing a new radon provision in the 1996 Safe Drinking Water Act amendments. That provision requires the EPA to set a new radon MCL, using the usual standard-setting approach, by August 2001. However, acceding to the industry argument that basement seepage is worse than tap water radon, Congress also adopted a provision in the 1996 law that allows the EPA to set an alternate, weaker MCL applicable in cities or entire states that adopt a multimedia mitigation program (MMM)

Tritium

National Standard (MCL)
20,000 pCi/L (average) (Part of 4 millirem beta and photon emitter standard)
National Health Goal (MCLG)
0—no known fully safe levelTRITIUM
SOME CONCERN
WASHINGTON, D.C.The EPA says tritium:
forms in the upper atmosphere through interactions between cosmic rays (nuclear particles coming from outer space) and the gases composing the atmosphere. Tritium can be deposited from the atmosphere onto surface waters via rain or snow and can accumulate in groundwater via seepage. Tritium is also formed from human activities. . . . Natural tritium tends not to occur at levels of concern, but contamination from human activities can result in relatively high levels. The man-made radionuclides, which are primarily beta and photon emitters, are produced by any of a number of activities that involve the use of concentrated radioactive materials. These radioactive materials are used in various ways in the production of electricity, nuclear weapons, nuclear medicines used in therapy and diagnosis, and various commercial products (such as televisions or smoke detectors), as well as in various academic and government research activities. Release of man-made radionuclides to the environment, which may include drinking water sources, are primarily the result of improper waste storage, leaks, or transportation accidents.153Health Effects

Tritium is a radioactive form of hydrogen that causes cancer. A beta particle emitter,
no level of exposure to it is considered safe. Treatment and Standard

The EPA says that beta emitters (such as tritium) are removed using ion exchange and
reverse osmosis.

Uranium
National Standard (MCL)
30 micrograms/liter (which EPA assumes to be equivalent to 30 pCi/L) (enforceable
December 2003)
National Health Goal (MCLG)
0—no known fully safe levelURANIUM
SOME CONCERN
LOS ANGELES
LITTLE OR NO CONCERN
SAN DIEGOUranium is released from minerals in the ground, often as the result of mining or
as a by-product of the nuclear industry. Health Effects

Uranium is radioactive and causes cancer when ingested.154 In addition, the EPA has
determined that uranium also causes serious kidney damage at levels above the MCL.Treatment and Standard

The EPA acknowledges that uranium poses a cancer risk at levels below its established MCL of 30 pCi/L, but the agency argues that the benefits of reducing uranium contamination of water are outweighed by the costs. That, at least, was the conclusion of the EPA’s cost-benefit analysis, in which it calculated costs to all U.S. water systems, including small systems where per-customer costs can be considerably higher than for larger systems. The cancer risk at 30 pCi/L is about 1 in 10,000, the highest cancer risk the EPA usually allows in drinking water, and about 100 times higher than the 1 in 1,000,000 risk the EPA allows for carcinogens under the Superfund or pesticide programs.155 Uranium is removed from water by many technologies, according to the EPA, including job exchange, lime softening, reverse osmosis, and enhanced coagulation followed by filtration.

REFERENCES 1

For general background information on Crypto, see Centers for Disease Control, "Parasitic Disease Information:

Cryptosporidiosis," available online at www.cdc.gov/ncidod/dpd/parasites/cryptosporidiosis/
factsht_cryptosporidiosis.htm. For more detailed information, see, "Cryptosporidium and Water: APublic Health Handbook," (CDC, 1997). Available online at www.cdc.gov/ncidod/diseases/crypto/crypto.pdf.

2 Ibid.

3 See CDC, "Parasitic Disease Information: Cryptosporidiosis," available online at www.cdc.gov/ncidod/dpd/parasites/cryptosporidiosis/factsht_cryptosporidiosis.htm. See also, CDC, "Cryptosporidiosis: AGuide for People with HIV/AIDS," available online at www.cdc.gov/ncidod/diseases/crypto/hivaids.htm.

4 W. R. MacKenzie, et al., "A Massive Outbreak in Milwaukee of Cryptosporidium Infection Transmitted Through the Public Water Supply," New England Journal of Medicine (1994), 331: 161–167. The precise number of people killed by the Milwaukee outbreak is not known with certainty. Account by the Milwaukee Journal puts the number at more than 100, although the "official" state and local health department count was "a minimum of 50 deaths." See Marilyn
Marchione, "Deaths continued after Crypto outbreak: State report attributes a minimum of 50 deaths from ‘93 to ‘95." The Milwaukee Journal Sentinel, (May 27, 1996).

5 See MacKenzie et al. supra; Erik Olson, The Dirty Little Secret About Our Drinking Water: New Data Show Over 100 Known Drinking Water Disease Outbreaks in the U.S. From 1986–1994, and Strong Evidence of More Widespread, Undetected Problems." (NRDC, 1995).

6 H. L. Dupont, C. L. Chappell, C. R. Sterling, P. C. Okhuysen, J. B. Rose, W. Jakubowski (1995). "The Infectivity of Cryptosporidium parvum in Healthy Volunteers," New England Journal of Medicine, 332(13): 855–859. "Human Cryptosporidiosis in Immunocompetent and Immunodeficient Persons: Studies of an Outbreak and Experimental Transmission," New England Journal of Medicine, 308(21): 1252–1257.

7 Environmental Protection Agency, "National Primary Drinking Water Regulations: Interim Enhanced Surface Water Treatment Rule," 63 Fed. Reg. 69477–69521 (December 16, 1998).

8 See EPA, "National Primary Drinking Water Regulation: Long Term 2 Enhanced Surface Water Treatment Rule, Draft," page 75 Table III-5, available online at www.epa.gov/safewater/lt2/lt2_preamble.pdf; M. W. LeChevallier and W. D. Norton, "Giardia and Cryptosporidium in Raw and Finished Water," Journal AWWA (1995), 87: 54–68.

9 Ibid.

10 See, e.g., EPA, "National Primary Drinking Water Regulation: Long Term 2 Enhanced Surface Water Treatment Rule, Draft," pg. 73 (". . . it is expected that Cryptosporidium oocysts were present in many more samples and were not detected due to poor recovery rates and low volumes analyzed. The observed data do not account for the ICR Method’s low recovery efficiencies. Adjusting for recovery would increase the estimated occurrence several-fold"), available online at www.epa.gov/safewater/lt2/lt2_preamble.pdf.

11 Ibid.

12 EPA, "National Primary Drinking Water Regulations: Interim Enhanced Surface Water Treatment Rule," 63 Fed.
Reg. 69477–69521 (December 16, 1998).

13 Note that the contaminant levels are presented as a percentage. Total coliform is regulated as a percentage of positive samples that are present in water. The national health standard of 5 percent means that if more than 5 percent of the utility’s total coliform samples test positive, then the national health standard has been violated. To say that a sample tests positive is to say that there are total coliform bacteria present in the sample. Therefore, for compliance purposes, the utilities provide the percentage of total coliform samples that tested positive.

14 The information on health effects of coliform is derived from EPA, "Total Coliform Rule," 54 Fed. Reg. 27544–27568, (June 29, 1989); EPA, "Total Coliform Rule," available online at www.epa.gov/safewater/source/therule.html#Total, and EPA, "Total Coliform Rule: AQuick Reference Guide," available online at Total Coliform Rule:
A Quick Reference Guide PDF file (816-F-01-035, September 2001).

15 "E. coli Death Toll Rises," available online at abcnews.go.com/sections/us/DailyNews/ecoli990911.html.

16 D. L. Swerdlow, B. A. Woodruff, R. C. Brady, P. M. Griffin, S. Tippen, H. Donnel Jr., E. Geldreich, B. J. Payne, A. Meyer Jr., J. G. Wells, K. D. Greene, M. Bright, N. H. Bean, and P. A. Blake. "A waterborne outbreak in Missouri of Escherichia coli O157:H7 associated with bloody diarrhea and death," Annals of International Medicine, 1992, 117(10): pg. 812–819.

17 "1,061 Suspected E. coli Cases in New York Outbreak," Infectious Disease News, October 1999, available online at www.infectiousdiseasenews.com/199910/frameset.asp?article=ecoli.asp; CDC, "Public health dispatch: Outbreak of Escherichia coli O157:H7 and Campylobacter among attendees of the Washington County Fair—New York," MMWR,
1999, 48(36): 803.

18 EPA, "Total Coliform Rule," available online at www.epa.gov/safewater/source/therule.html#Total.

19 Ibid.

20 40 C.F.R. 141.

21 & 141.63.

21 Ibid.

22 See note 18.

23 Ibid.

24 40 C.F.R. 141.21.

25 EPA, "Total Coliform Rule," 54 Fed. Reg. 27544-27568, June 29, 1989; EPA, "Total Coliform Rule," available online at www.epa.gov/safewater/source/therule.html#Total, and EPA, "Total Coliform Rule: AQuick Reference Guide," (available online at Total Coliform Rule: A Quick Reference Guide PDF file (816-F-01-035, September 2001).

26 Ibid.

27 EPA, "Fact Sheet: National Primary Drinking Water Regulations" (2002), available online at www.epa.gov/safewater/mcl.html.

28 See W. R. MacKenzie, et al., "A Massive Outbreak in Milwaukee of Cryptosporidium Infection Transmitted Through the Public Water Supply," New England Journal of Medicine, 1994, 331:161–167. As noted above, a precise number of people killed by the Milwaukee outbreak is not known with certainty, but the Milwaukee Journal puts the number at more than 100, although the "official" state and local health department count was "a minimum of 50 deaths." See Marilyn Marchione, "Deaths continued after Crypto outbreak: State report attributes a minimum of 50 deaths from ‘93 to ‘95," The Milwaukee Journal Sentinel, May 27, 1996.

29 EPA, "National Primary Drinking Water Regulations: Interim Enhanced Surface Water Treatment Rule," 63 Fed. Reg. 69477-69521 (December 16, 1998).

30 See W. R. MacKenzie, et al., "A Massive Outbreak in Milwaukee of Cryptosporidium Infection Transmitted Through the Public Water Supply," New England Journal of Medicine, 1994, 331:161–167.

31 See EPA, "National Primary Drinking Water Regulation: Long Term 2 Enhanced Surface Water Treatment Rule, Draft," page 75 Table III-5, available online at www.epa.gov/safewater/lt2/lt2_preamble.pdf.

32 Available online at www.nap.edu/catalog/6444.html.

33 National Academy of Sciences, National Research Council, Arsenic in Drinking Water: 2001 Update (National Academy Press, 2001), available online at www.nap.edu/catalog/10194.html.

34 Total cancer risk figures are taken from the National Academy of Sciences’ report Arsenic in Drinking Water: 2001 Update (2001); for a plain-English explanation of the Academy's arsenic cancer risk figures, see NAS's September 11, 2002, press release, available online at www4.nationalacademies.org/news.nsf/isbn/0309076293?OpenDocument. EPA’s maximum acceptable cancer risk is 1 in 10,000.

35 See NAS’s September 11, 2002, press release, available online at www4.nationalacademies.org/news.nsf/isbn/0309076293?OpenDocument.

36 EPA, National Primary Drinking Water Regulation for Arsenic, 66 Fed. Reg. 6976, at 6981 (January 22, 2001).

37 Ibid, at 7011, Table III E-2.

38 See Report of the Arsenic Cost Working Group to the National Drinking Water Advisory Council, August 14, 2001,
available online at www.epa.gov/safewater/ars/ndwac-arsenic-report.pdf.39 For a review of the history of the arsenic standard and the health effects of arsenic, see Paul Mushak, et al. Arsenic
and Old Laws (NRDC, 2000).40 EPA, National Primary Drinking Water Regulation for Arsenic, 66 Fed. Reg. 6976, at 6981 (January 22, 2001).

41 NAS, National Research Council, Arsenic in Drinking Water: 2001 Update (National Academy Press, 2001), available
online at www.nap.edu/catalog/10194.html.

42 Ibid.; see also NAS’s September 11, 2002, press release, available online at www4.nationalacademies.org/
news.nsf/isbn/0309076293?OpenDocument.

43 EPA, Consumer Fact Sheet: Chromium, available online at www.epa.gov/safewater/dwh/c-ioc/chromium.html.

44 See EPA, "National Primary Drinking Water Regulations; Announcement of the Results of EPA’s Review of
Existing Drinking Water Standards and Request for Public Comment; Proposed Rule," 67 Fed. Reg. 19030, at 19057-58
(April 17, 2002).45 See note 43.

46 EPA, "Consumer Fact Sheet: Cyanide," available online at www.epa.gov/safewater/dwh/c-ioc/cyanide.html.

47 Ibid. 48 Ibid. 49 Ibid.

50 The action level standard for lead is different from the standard for most other contaminants. Water utilities are required to take many samples of lead in the tap water at homes they serve, including some high-risk homes judged likely to have lead in their plumbing or fixtures. If the amount of lead detected in the samples is more than 15 ppb at the 90th percentile (which means that 90 percent of the samples have 15 ppb or less), then the amount is said to exceed the action level. Under the complex EPAlead rule, a water system that exceeds the action level is not necessarily in violation. If a system exceeds the action level, additional measures such as chemical treatment to reduce the water’s corrosivity (ability to corrode pipes and thus its ability to leach lead from pipes) must be taken. If this chemical treatment does not work, the water system may have to replace lead portions of its distribution system if they are still contributing to the lead problem.51 See EPA, "Consumer Fact Sheets on Lead," www.epa.gov/safewater/Pubs/lead1.html and www.epa.gov/safewater/standard/lead&co1.html, and IRIS summary for lead available online at www.epa.gov/iris/subst/0277.htm.

52 Ibid.

53 40 C.F.R. §141.80-141.91.

54 Ibid.; for a review of the sampling and monitoring requirements as amended by the "lead and copper rule minor revisions," see EPA, "Lead and Copper Rule Minor Revisions: Fact Sheet for Public Water Systems Serving More than 50,000 Persons," available online at www.epa.gov/safewater/lcrmr/largefs.pdf.

55 SDWA§ 1417.56 Ibid; see also EPA, "Nitrates." Fact sheet available online at www.epa.gov/safewater/dwh/c-ioc/nitrates.html.

57 Ibid.

58 The information regarding the health effects of nitrate are derived from NAS, National Research Council, Nitrate and Nitrite in Drinking Water, 1995, available online at www.nap.edu/catalog/9038.html), and EPA, "Nitrates." Fact sheet available online at www.epa.gov/safewater/dwh/c-ioc/nitrates.html).

59 Ibid.60 Ibid.

61 See, e.g., L. Knobeloch, B. Salna, A. Hogan, J. Postle, H. Anderson, "Blue babies and nitrate-contaminated wellwater," Environmental Health Perspectives (July 2000), 108(7): 675–8.

62 "Spontaneous abortions possibly related to ingestion of nitrate-contaminated well water—LaGrange, Indiana,
1991–1994," MMWR (1996), 45(26): 569–572.63 L. A. Croen, K. Todoroff, G. M. Shaw, "Maternal exposure to nitrate from drinking water and diet and risk for
neural tube defects," American Journal of Epidemiology, 2001, 153(4).

64 EPA, "Nitrates." Fact sheet available online at www.epa.gov/safewater/dwh/c-ioc/nitrates.html.

65 See L. Knobeloch, B. Salna, A. Hogan, J. Postle, H. Anderson, "Blue babies and nitrate-contaminated well water," Environmental Health Perspectives, July 2000, 108(7): 675-8; see also EWG, Pouring It On: Nitrate Contamination of Drinking Water (1995), available online at www.ewg.org/reports/Nitrate/NitrateHealth.html.

66 For a list of stricter standards overseas, see EWG, Pouring It On: Nitrate Contamination of Drinking Water (1995), available online at www.ewg.org/reports/Nitrate/NitrateHealth.html.

67 NAS, National Research Council, Nitrate and Nitrite in Drinking Water (1995), available online at www.nap.edu/
catalog/9038.html.

68 See note 56 (noting emerging evidence that nitrate exposure may pose miscarriage and reproductive risks, cancer risks, thyroid risks, and diabetes risks, and that even exposure as low as 12 ppm has been linked to blue baby syndrome); EWG, Pouring It On: Nitrate Contamination of Drinking Water (1995), available online at www.ewg.org/reports/Nitrate/NitrateHealth.html (noting evidence of chronic risks not considered by NAS).

69 Ibid.

70 Adrinking water equivalent level is the presumed level of perchlorate that one would need to consume in tap water to reach the Reference Dose—the maximum safe level. See EPA, "Perchlorate," fact sheet available online at www.epa.gov/safewater/ccl/perchlor/perchlo.html.

71 MWD is well aware that this Henderson facility is the source of this perchlorate. See MWD, "In the News: Perchlorate," available online at www.mwdh2o.com/mwdh2o/pages/yourwater/ccr02/ccr03.html; MWD press release, "Water Officials Report Significant Progress in Perchlorate Removal," April 17, 2002. This release puts an unduly optimistic face on the problem, since MWD is well aware that the cleanup of the facility remains problematic and partially unsuccessful. See also Environmental Working Group, Rocket Science (2001), available online at www.ewg.org/reports/rocketscience.

72 See California Department of Health Services, "Perchlorate in Califrona Drinking Water," available online at
www.dhs.cahwnet.gov/ps/ddwem/chemicals/perchl/perchlindex.htm; see also EWG, Rocket Science (2001), available online at www. ewg.org/reports/rocketscience/.

73 Ibid.; see also California Office of Environmental Health Assessment, Draft Public Health Goal for Perchlorate in Drinking Water (March 2002), available online at www.oehha.org/water/phg/pdf/PHGperchlorate372002.pdf.

74 EPA, "Perchlorate," fact sheet available online at www.epa.gov/safewater/ccl/perchlor/perchlo.html.

75 See EPA, "Perchlorate," fact sheet (2002) (perchlorate was listed on the contaminant candidate list in 1998, and study is continuing), available online at www.epa.gov/safewater/ccl/perchlor/perchlo.html; see also EPA, "Announcement of Preliminary Regulatory Determinations for Priority Contaminants on the Drinking Water Contaminant Candidate List," 67 Fed. Reg. 38222 (June 3, 2002) (no regulatory determination made for perchlorate), available online at www.epa.gov/ogwdw/ccl/pdf/prelimreg_fr.pdf.76 See note 74.

77 EPA, "Consumer Fact Sheet: Thallium," available online at
www.epa.gov/safewater/dwh/c-ioc/thallium.html.

78 Ibid 79 Ibid. 80 Ibid.

81 Ibid.82 Ibid.83 EPA, "Consumer Fact Sheet: Atrazine," available online at www.epa.gov/safewater/dwh/c-soc/atrazine.html.84 USGS data, cited in NRDC, Atrazine: An Unacceptable Risk to America’s Children & Environment (June 2002).

85 Ibid.86 Ibid.; see also note 84.

87 See note 83.88 Ibid.89 See NRDC, Atrazine: An Unacceptable Risk to America’s Children & Environment (June 2002).90 Syngenta’s prostate cancer data and other atrazine data are summarized in NRDC, Atrazine: An Unacceptable Risk to America’s Children & Environment (June 2002).91 EPA, "Common Mechanism of Action Determination for the Triazines," summary available online at www.epa.gov/pesticides/cumulative/triazines/newdocket.htm.92 EPA, "Consumer Fact Sheet on 1,2-Dichlorethylene," available online at www.epa.gov/safewater/dwh/c-voc/12-dich2.html.

93 Health effects and other general information on DBCP derived from EPA, "Consumer Fact Sheet on Dibromochloropropane," available online at www.epa.gov/safewater/dwh/c-soc/dibromoc.html.

94 Information derived from EPA, "Consumer Fact Sheet on Dichloromethane," available online at www.epa.gov/safewater/dwh/c-voc/dichloro.html.

95 Philadelphia Water Department, "Drinking Water Quality 2001," available online at www.phillywater.org/
wqr2001/wqr2001.htm. Last visited September 15, 2002. Published April 2002.96 Information derived from EPA, "Consumer Fact Sheet on Dichloromethane," available online at
www.epa.gov/safewater/dwh/c-voc/dichloro.html.97 Ibid.98 EPA, "Consumer Fact Sheet on DEHP," www.epa.gov/safewater/dwh/c-soc/phthalat.html.99 Ibid.100 EPA, "Consumer Fact Sheet on Ethylene Dibromide," available online at www.epa.gov/safewater/dwh/csoc/
ethylene.html.101 Ibid.
102 Ibid.103 Some of the haloacetic acids have national health goals of 0 and others have nonzero goals. For the sake of
simplicity and understandability, since there is a single haloactetic acid standard, and because it is essentially
chemically impossible under normal conditions in tap water to create one regulated haloacetic acid without creating
the others at some level, we have listed the national health goal as 0.104 Total trihalomethanes (TTHMs) consist of a sum of the levels of four closely related chemicals—chloroform,
dibromochloromethane, bromoform, and bromodichloromethane—which occur together at varying ratios when
water is chlorinated. The latter two TTHMs have health goals of 0. The EPApromulgated and then withdrew (after
a court decision) a 0 health goal for chloroform and has not yet issued a new goal for chloroform. Dibromochloromethane
has a health goal of 60 ppb. Since water systems generally report only the combined TTHM level, and since it is essentially chemically impossible to create one trihalomethane in tap water without some level of the others, we list the health goal for TTHMs as 0.

105 See, e.g., K. P. Cantor, C. F. Lynch, M. E. Hildesheim, M. Dosemeci, J. Lubin, M. Alavanja, G. Craun. "Drinking water source and chlorination by-products. I. Risk of bladder cancer," Epidemiology (January 1998), 9(1): 21–28; M. E. Hildesheim, K. P. Cantor, C. F. Lynch, M. Dosemeci, J. Lubin, M. Alavanja, G. Craun. "Drinking water source and chlorination by-products. II. Risk of colon and rectal cancers," Epidemiology (January 1998), 9(1) 29-35; W. D. King, L. D. Marrett, C. G. Woolcott, "Case-control study of colon and rectal cancers and chlorination by-products in treated water," Cancer Epidemiology. Biomarkers Prev., (August 2000), 9(8): 813-8; C. B. Jsselmuiden, C. Gaydos, B. Feighner, W. L. Novakoski, D. Serwadda, L. H. Caris, D. Vlahov, G. W. Comstock, "Cancer of the pancreas and drinking water: a population-based case-control study in Washington County, Maryland," Am. J. Epidemiology. (October 1, 1992), 136(7): 836–42. For a review of this issue, see Erik Olson, et al., Trouble on Tap (NRDC, 1995); Erik Olson, et al., Bottled Water: Pure Drink or Pure Hype?(NRDC, 1999), available online at www.nrdc.org/water/drinking/bw/bwinx.asp; and EPAdraft, "Preamble for Stage 2 Disinfection By-products Regulation," available online at www.epa.gov/safewater/mdbp/st2dis-preamble.pdf.

106 K. P. Cantor, C. F. Lynch, M. E. Hildesheim, M. Dosemeci, J. Lubin, M. Alavanja, G. Craun, "Drinking water source and chlorination by-products in Iowa. III. Risk of brain cancer," Am. J. Epidemiology. (September 15, 1999), 150(6): 552–60.

107 C. Infante-Rivard, E. Olson, L. Jacques, P. Ayotte, "Drinking water contaminants and childhood leukemia,"
Epidemiology (January 2001,) 12(1): 13-9.

108 See M. J. Nieuwenhuijsen, M. B. Toledano, N. E. Eaton, J. Fawell, P. Elliott, "Chlorination disinfection byproducts
in water and their association with adverse reproductive outcomes: a review." Occupational and
Environmental Medicine (February 2000), 57(2): 73-85; F. Bove, Y. Shim, P. Zeitz, "Drinking water contaminants and
adverse pregnancy outcomes: a review," Environmental Health Perspectives (February 2002), (110 Suppl. 1):61–74.

109 K. Waller, S. H. Swan, et al., "Trihalomethanes in drinking water and spontaneous abortion," Epidemiology, (March 1998), 9(2): 134–140; S. H. Swan, K. Waller, et al., "A prospective study of spontaneous abortion: relation to amount and source of drinking water consumed in early pregnancy," Epidemiology (March 1998), 9(2): 126–133.

110 M. J. Nieuwenhuijsen, M. B. Toledano, N. E. Eaton, J. Fawell, P. Elliott, "Chlorination disinfection by-products in water and their association with adverse reproductive outcomes: a review," Occupational and Environmental Medicine (February 2000), 57(2): 73–85.

111 Ibid.

112 See Interim National Primary Drinking Water Regulation for Trihalomethanes, 44 Fed. Reg. 68624 (1979).

113 EPA, "National Primary Drinking Water Regulations: Disinfectants and Disinfection By-products," 63 Fed. Reg.
69389 (December 16, 1998).

114 Ibid.

115 EPAdraft, "Preamble for Stage 2 Disinfection By-products Regulation," available online at www.epa.gov/safewater/mdbp/st2dis-preamble.pdf.

116 Ibid 117 EPA, "Consumer Fact Sheet on: Hexachlorocyclopentadiene" available online at www.epa.gov/safewater/dwh/c-soc/hexachl2.html.

118 Ibid.

119 EPA, "MTBE in Drinking Water," available online at www.epa.gov/safewater/mtbe.html.

120 Ibid. 121 Ibid.

122 Ibid; Toccalino, P., "Human Health Effects of MTBE: ALiterature Summary," USGS, available on the Web at http://sd.water.usgs.gov/nawqa/vocns/mtbe_hh_summary.html; citing inter alia Agency for Toxic Substances and Disease Registry, 1996, Toxicological profile for methyl t-butyl ether (MTBE): Atlanta, GA, U.S. Department of Health and Human Services, Public Health Service, August 1996, 268 p., http://atsdr1.atsdr.cdc.gov/toxprofiles/tp91.html;
Health Effects Institute, 1996, The potential health effects of oxygenates added to gasoline. Areview of the current literature. Aspecial report of the Institute's oxygenates evaluation committee: Cambridge, MA, Health Effects Institute, April 1996, www.healtheffects.org/Pubs/oxysum.htm; National Institute of Environmental Health Sciences,
2002, MTBE (in gasoline): National Institute of Environmental Health Sciences, March 13, 2002, www.niehs.nih.gov/external/faq/gas.htm; National Research Council, 1996, Toxicological and performance aspects of oxygenated motor vehicle fuels: Washington, D.C., National Academy Press, 160 p.; National Science and Technology Council, 1996, Interagency assessment of potential health risks associated with oxygenated gasoline: Washington, DC, National Science and Technology Council, Committee on Environment and Natural Resources, February 1996. www.ostp.gov/NSTC/html/MTBE/mtbe-top.htm l; Office of Science and Technology Policy, 1997, Interagency assessment of oxygenated fuels: Washington, DC, Office of Science and Technology Policy, National Science and Technology Council, Executive Office of the President of the United States, June 1997, 264 p., www.epa.gov/oms/regs/fuels/ostpfin.pdf.

123 EPA, "Fact Sheet: Drinking Water Advisory: Consumer Acceptability Advice and Health Effects Analysis on Methyl Tertiary-Butyl Ether (MTBE)," available online at www.epa.gov/waterscience/drinking/mtbefact.pdf.

124 Ibid.

125 EPA, "Consumer Fact Sheet: Pentachloropehenol," available online at www.epa.gov/safewater/dwh/csoc/pentachl.htm l; see also EPA, "Technical Fact Sheet on Pentachlorophenol," available online at www.epa.gov/safewater/dwh/t-soc/pentachl.html.

126 Ibid. 127 Ibid.

128 EPA, "Consumer Fact Sheet on Simazine," available online at www.epa.gov/safewater/dwh/c-soc/simazine.html.

129 Ibid. 130 Ibid.

131 EPA, "Common Mechanism of Action Determination for the Triazines," summary available online at
www.epa.gov/pesticides/cumulative/triazines/newdocket.htm.

132 See note 130.

133 EPA, "Consumer Fact Sheet on Tetrachloroethylene," available online at www.epa.gov/safewater/dwh/cvoc/
tetrachl.html.

134 Ibid.

135 Ibid.

136 EPA, "Consumer Fact Sheet on Toluene," available online at www.epa.gov/safewater/dwh/c-voc/toluene.html.

137 Ibid.

138 Ibid.

139 Ibid.

140 Ibid.

141 EPA, "Consumer Fact Sheet on Tetrachloroethylene," available online at www.epa.gov/safewater/dwh/cvoc/
trichlor.html.

142 Ibid.; see also Agency for Toxic Substances and Disease Registry, "ToxFAQs—Trichloroethylene (TCE)"
(September 1997), available online at www.atsdr.cdc.gov/tfacts19.html.

143 Information derived from EPA, "Consumer Fact Sheet on: Vinyl Chloride," available online at
www.epa.gov/safewater/dwh/c-voc/vinylchl.html.

144 Ibid.

145 See EPAfact sheets on radionuclides for information on health effects and sources, available online at www.epa.gov/safewater/hfacts.html#Radioactive; and available online at www.epa.gov/safewater/rads/technicalfacts.html.

146 EPA, "National Primary Drinking Water Regulation: Radionuclides," 65 Fed. Reg. 76707, at 76722 (December 7, 2000).147 EPA, "Proposed National Primary Drinking Water Regulation: Radon," 64 Fed. Reg. 59245 (November 2, 1999).

148 The information in the radon section is derived from NAS, National Research Council, Risk Assessment of Radon in Drinking Water, 1999, available online at http://books.nap.edu/books/0309062926/html/index.html), and from EPA, "Radon in Drinking Water Fact Sheet," available online at www.epa.gov/safewater/radon/proposal.html.

149 Ibid.150 NAS, Risk Assessment of Radon in Drinking Water, supra.

151 See note 147, at 59328 Table XIII.11.

152 See note 147, at 59270 Table VII.1.

153 EPA, "Implementation Guidance for the Radionuclides Rule," at page IV-8 (draft, January 2002), available online
at www.epa.gov/safewater/rads/fullradsimpguide.pdf.

154 Health effects information is derived from EPA’s final rule issued in December 2000, 65 Fed. Reg. 76708,
(December 7, 2000), available online at www.epa.gov/safewater/rads/radfr.pdf.

155 EPA, "Final Radionuclides National Primary Drinking Water Regulation," 65 Fed. Reg, 76708, page 76715,
(December 7, 2000).

Water Contanimination, Part 1.




Heart

Author The Natural Resources Defense Council




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