Lead in Drinking Water: Washington, D.C. Issues and Broader Regulatory Implications
CRS Report for Congress
Lead in Drinking Water: Washington, DC,
Issues and Broader Regulatory Implications
Mary Tiemann
Specialist in Environmental Policy
Resources, Science, and Industry Division
Summary
Lead from various sources poses a key environmental threat to children’s health,
and the regulation of lead in drinking water has been a key component of federal efforts
to reduce exposures to lead. Lead contamination of drinking water became a major issue
in Washington, DC, in 2004, when news reports revealed marked increases in the levels
of lead in tap water. The local water authority’s failure to effectively inform the public
about the high lead levels angered citizens and damaged public trust in the local water
supply. These events led policy makers to examine the adequacy of the Environmental
Protection Agency’s (EPA’s) lead in drinking water rule, including the rule’s monitoring
and public notification requirements, and EPA and state enforcement of the rule.
Oversight hearings were held on these issues during the 108th Congress, and legislation
to strengthen lead regulation was offered but not enacted. This report reviews issues
surrounding the elevated lead levels in DC drinking water and actions to address this
problem. More broadly, it discusses the lead regulatory framework, and EPA’s national
review of the rule and its implementation to determine whether the situation in
Washington, DC, denotes a wider problem in need of a broader response. This report
will be updated to reflect developments.
Overview
In January 2004, the Washington Post reported that the DC Water and Sewer
Authority (WASA) had found elevated lead levels in the drinking water of more than
4,000 homes in Washington, DC, during testing done in 2003.1 Subsequently, water
suppliers, local officials, and regulators have undertaken numerous actions intended to
respond to citizens’ concerns; to abate further exposures to lead from tap water; to
identify the cause of the problem; and, ultimately, to reduce the occurrence of lead in
DC’s water and assess whether similar problems are occurring in other cities.
1 “Water in D.C. Exceeds EPA Lead Limit,” Washington Post, January 31, 2004, pp. A1, A11.
Congressional Research Service ˜ The Library of Congress
National Review. To determine whether the problem in Washington, DC, is more
widespread and to evaluate the effectiveness of the lead rule, EPA has undertaken a
national review of lead monitoring conducted by water systems from 2000 through 2003.
As of June 2004, EPA had received monitoring data for 744 (89%) of the 834 systems
that serve more than 50,000 persons. EPA reported that 27 (3.6%) of these systems
exceeded the action level of 15 parts per billion (ppb) at least once since 2000, and that
12 of 316 systems reported exceeding the action level during the monitoring period
ending after January 2003.2 (These 12 systems serve a total population of 5.2 million
people.) Among all systems serving more than 50,000 persons, 66% reported that the
highest level observed during any monitoring period since 2000 was less than 5 ppb. EPA
also received data for 6,678 (91%) of 7,833 systems that serve from 3,300 to 50,000
people. Of these systems, 237 (3.4%) reported exceeding the action level at least once
since 2000, and 76 systems (serving a total population of 5.2 million) reported exceeding
the level for a monitoring period ending after January 2003. In this size category, 71%3
of systems reported that the highest level observed since 2000 was less than 5 ppb. In
each size category, 1% of water systems reported exceeding 25 ppb.
Last autumn, news reports of possible manipulation of lead monitoring data by some
systems to avoid noncompliance with the lead rule raised concern that a larger number of
systems may have exceeded the action level. In response, several Members of Congress
asked the EPA Inspector General to examine the adequacy of enforcement of the lead
rule, and to determine whether elements of the rule allow data manipulation so that
systems remain in compliance. EPA announced that if utilities have violated the law by
providing false or misleading data, EPA or the state would take appropriate enforcement4
actions. However, in its evaluation of the rule and monitoring concerns, EPA did
determine that systems needed more guidance for collecting samples and calculating theth
lead 90 percentile to determine compliance with the rule. In November, EPA issued a
memorandum clarifying these requirements. The guidance reflects requirements of the
lead rule as currently written and may be modified if EPA decides to revise the rule.
Health Effects of Lead. Lead exposure is considered a major environmental
health threat to young children, because lead affects their developing nervous systems and
intellectual and behavioral development. Fetuses and children under six years of age are
most at risk. In 1991, the Centers for Disease Control (CDC) adopted a blood lead level
of concern for children of 10 micrograms per deciliter (:g/dl) in response to evidence
associating adverse health effects with blood lead levels above that level. Recent studies
indicate that blood lead levels below 10 :g/dl also may be associated with negative effects
on children’s intellectual development.5 In adults, lead may increase blood pressure.
2 EPA’s 1991 lead rule required community water systems to conduct initial monitoring by
December 1992. The results of the first round of monitoring for systems serving more than
3 For information on lead action level exceedances for water systems serving populations of 3,300
or more, see [http://www.epa.gov/safewater/lcrmr/lead_data.html], visited January 6, 2005.
4 U.S. Environmental Protection Agency, Agency Statement: Drinking Water and Lead, Oct. 6,
5 R. Canfield et al., “Intellectual Impairment in Children with Blood Lead Concentrations below
(continued...)
Sources of Lead Exposure. Lead is widespread in the environment and can be
found in older homes with leaded paint, and in soil, plumbing materials, pottery glazes,
pewter, and elsewhere. The main source of lead exposure for children is house dust from
lead-based paint; exposure to small amounts of paint dust and flakes can elevate blood
lead levels. Another major source is soil contaminated by lead-based paint and past
vehicle and industrial emissions.6 EPA estimates that 10% to 20% of exposure to lead
may come from drinking water, but notes that infants who consume mostly mixed formula
can receive 40% to 60% of their lead from water if lead levels are elevated in tap water.7
Lead is rarely present in water when it leaves a treatment plant. The most common
sources of lead in water are lead service lines that connect water mains to homes, lead
solder and pipes within homes, and brass plumbing fixtures. Although older homes are
most likely to have lead pipes, joints, and solder, new homes may also be at risk, because
under the Safe Drinking Water Act, “lead-free” pipes may contain up to 8% lead. These
pipes can leach lead for several months following installation. The most common cause
of lead in drinking water is corrosion, a reaction between the lead pipes or solder and the
water. The corrosivity of water depends on the water’s characteristics (such as acidity).
EPA’s 1991 Lead and Copper Rule
The Safe Drinking Water Act (SDWA) directs EPA to promulgate National Primary
Drinking Water Regulations for contaminants that may pose public health risks and that
are likely to be present in public water supplies. These regulations generally include an
enforceable numerical standard (maximum contaminant level (MCL)) to limit the amount
of a contaminant that may be present in drinking water. If it is not economically and
technically feasible to determine the level of a contaminant, EPA may establish a
treatment technique in lieu of an MCL (§1412(b)(7)(A)). At least once every six years,
EPA must review, and revise as needed, each drinking water regulation (§1412(b)(9)).
The 1986 SDWA Amendments directed EPA to issue a new lead regulation, and in
1991, EPA issued the Lead and Copper Rule (56 FR 26460, June 7, 1991). This rule
replaced an interim lead standard of 50 parts per billion (ppb), which was outdated and
not protective of public health. Moreover, the interim regulation did not require sampling
at the tap to show compliance with the standard.
In 1988, EPA had proposed a lead rule that would have lowered the MCL for lead
to 5 ppb (applied to water leaving the plant) and also would have required a treatment
technique (corrosion control) to further reduce lead in water. Many expressed concern
with the proposed rule, arguing that a standard applicable at the treatment plant would not
5 (...continued)
6 In 1971, Congress passed the Lead-Based Paint Poisoning Prevention Act, which limited lead
in interior paint starting in 1978. In 1973, EPA issued a regulation phasing out lead in gasoline.
Since these actions, average blood lead levels (BLLs) in children have declined markedly.
According to the CDC, for the period 1976-1980, 88% of children aged 1 through 5 were
estimated to have BLLs greater than 10 µg/dl; by 1999-2000, this estimate declined to about 2%.
7 U.S. Environmental Protection Agency, Lead in Drinking Water, at [http://www.epa.gov/
safewater/lead/leadfacts.html#tapwater], visited January 6, 2005.
indicate the amount of lead in tap water, and that compliance at the tap was essential.
EPA and utilities were concerned that an MCL applied at the tap was not workable,
because lead in household plumbing could be a major cause of violations — a situation
beyond the control of the water system. Some utilities also were concerned that setting an
MCL for source water in addition to a treatment technique for corrosion control would
result in confusion among the public and the regulated community (56 FR 26472).
The final 1991 Lead and Copper Rule (LCR) did not include an enforceable standard
(MCL). Instead, the LCR established a treatment technique (corrosion control) to prevent
lead and copper from leaching into drinking water. Other requirements include tap water
monitoring, public education, source water treatment, and lead service line replacement.
Some Members of Congress and environmental groups argued that, because lead is
measurable, the law required EPA to establish an MCL rather than a treatment technique.
However, EPA concluded that an MCL at the tap was not feasible because lead levels are
often influenced by factors beyond the control of the water utility.
The rule generally required all large water systems (serving more than 50,000
people) to conduct corrosion control studies and recommend an optimal corrosion control
treatment to the state or EPA. Smaller systems were required to optimize corrosion
control when tap water monitoring showed that it was necessary. The state or EPA then
approved or designated a treatment as optimal, and water systems were given two years
to install optimal corrosion control and one year to conduct further monitoring.
The lead rule also established a lead “action level” of 15 ppb at the tap, based on the
90th percentile level of water samples. Water systems are required to sample tap water in
locations that are at high risk of lead contamination (primarily homes with lead pipes
and/or lead service lines). The number of samples a water system must take depends on
the system’s size and the results of earlier testing. Large systems generally must take 100
samples in a six-month monitoring period. However, systems that meet the action level
or maintain optimal corrosion control treatment for two consecutive six-month periods
may reduce the number of sampling sites (to 50 sites for systems serving more
than100,000 people) and reduce collection frequency to once a year. Monitoring may be
reduced to once every three years if the 90th percentile lead levels are 5 ppb or lower.
If lead concentrations exceed the action level in more than 10% of samples, the water
system has 60 days to deliver an EPA-developed public education program to customers.
The education program must contain information about lead’s health effects and sources,
and explains steps to take to reduce exposure to lead. The water system also must offer
to sample the tap water of any customer who requests it. (The system is not required to
pay for sample collection or analysis.) If a water system still exceeds the action level after
installing optimal corrosion control treatment and source water treatment, it must replace
annually 7% of the lead service lines under its ownership. The water system must offer
to replace the privately owned portion of a service line (at the owner’s expense).
Addressing Lead in DC Drinking Water
The Safe Drinking Water Act allows EPA to delegate primary enforcement authority
(primacy) for the Public Water System Supervision (PWSS) Program to states. States that
have primacy oversee water systems and their compliance with federal drinking water
regulations. If primacy is not delegated to a state, EPA is responsible for implementing
the program. (All states except Wyoming have primacy for the PWSS program.) EPA
Region 3 directly implements the program for the District of Columbia. The water
systems for the District of Columbia that are overseen by EPA Region 3 are the
Washington Aqueduct (owned by the U.S. Army Corps of Engineers), which treats the
city’s drinking water, and the DC Water and Sewer Authority (WASA), which buys water
from the Washington Aqueduct and distributes it throughout Washington, DC. The
aqueduct also provides water to several communities in Northern Virginia.
In March 2004, EPA reported that WASA exceeded the action level at the 90th
percentile for taps monitored during 6 out of 15 reporting periods since January 1992
(three times before 1994 and three times since 2002). EPA, WASA, and other local
officials worked with the Corps of Engineers to determine the cause of the elevated levels.
It appears that changes in treatment processes at the Washington Aqueduct made the
water more corrosive, causing more lead to leach from lead pipes in the distribution
system and from lead plumbing inside homes. In November 2000, the Corps had changed
its secondary disinfection treatment from free chlorine to chloramines to comply with a
new EPA regulation that placed strict limits on disinfection byproducts. After that, more
than 10% of tap water samples taken by WASA exceeded the action level.8
As a result of this finding, the Corps of Engineers worked with a technical work
group to develop a new corrosion control process. In June, the Corps tested a process that
uses orthophosphate, and found no negative effects. This commonly used compound is
expected to form a protective coating in pipes and reduce lead leaching. In August, EPA
approved use of the process for the entire aqueduct service area and imposed
supplemental monitoring and reporting requirements on the affected public water systems.
EPA determined that WASA had failed to comply with numerous sampling, public
notification, and reporting requirements contained in the lead rule. EPA and WASA
reached a consent agreement requiring WASA to improve its public education program,
upgrade its database management systems, and replace more than 1,600 lead service lines.
In response to high lead levels in Washington, DC tap water, the DC Department of
Health (DOH) and the U.S. Public Health Service offered blood testing for residents.
Through May 2004, 5,331 individuals had been screened. Of that total, 1,954 individuals
were from their target population (children under the age of six, and pregnant and nursing
women). Within that population, 40 children (2.2%) had elevated lead levels (i.e., 10
:g/dl or higher); 26 lived in homes without lead service lines. All except one of the homes
of the children with elevated blood lead levels were found to have dust and/or soil lead
levels that exceed federal guidelines.9 Also, a recent CDC analysis of blood lead levels
among DC residents found an overall decline in blood lead levels since 1998. None of
8 Studies show that a switch from free chlorine to chloramines can greatly increase lead leaching.
Mechanisms that may cause this effect include the following: (1) free chlorine reduces lead
solubility compared to chloramine; (2) chloramines can greatly increase lead leaching from brass;
and (3) a galvanic connection between lead pipe-lead solder to copper pipe may be involved
(effects of chloramine on leaching from new lead pipe do not seem significant). Marc Edwards
and A. Dudi, “Role of Chlorine and Chloramine in Corrosion of Lead-Bearing Plumbing
Materials,” Journal of the American Water Works Association, Oct. 2004, v. 96, n. 10, pp. 69-81.
9 District of Columbia, Department of Health, Blood Lead Level Screening Results. May 2004.
the 201 persons tested who live in homes with the highest levels of lead in drinking water
(i.e., above 300 ppb) had blood lead levels above CDC’s levels of concern.10
Regulatory and Congressional Issues
The detection of high lead levels in Washington, DC, tap water, and the failure of
officials to effectively notify the public of the detections, renewed congressional interest
in examining the adequacy of the lead rule, including its monitoring and public
notification requirements and overall enforcement of, and compliance with, the lead rule.
During the 108th Congress, the House Energy and Commerce and Government Reform
Committees and the Senate Environment and Public Works Committee held hearings on
this issue, and bills were introduced to strengthen the regulation of lead in drinking water.
In March 2004, members of the House Government Reform Committee requested
that the EPA Administrator review the lead rule. The committee members and others
argued that regulatory gaps appear to be undermining the rule’s effectiveness in protecting
public health. Issues that were raised include the following: (1) monitoring under the LCR
may not be broad or frequent enough to indicate the level of lead exposure in a
community; (2) allowing 10% of samples to exceed the action level without requiring
systems to take steps to reduce lead levels allows known exposures to continue; (3) the
rule does not require systems to notify homeowners of monitoring results; (4) systems are
given 15 years to replace lead service lines, and once the action level is met in 90% of
samples, the system may discontinue this effort; and (5) unlike an MCL, the action level
is not enforceable (exceedances of the action level trigger other regulatory requirements).
Critics expressed concern that this regulatory structure may have delayed the response to
high lead levels in Washington, DC, and could allow significant lead problems to go
undetected or unaddressed in cities nationwide.
EPA is conducting a thorough review of the lead rule to determine how well it has
worked, whether it is being effectively implemented and enforced, and whether it needs
revision. Elements of the rule receiving most scrutiny include the public notification,
monitoring, and lead service line replacement requirements. In October 2004, the agency
announced that the national data from 73,000 water utilities demonstrated that lead in
drinking water is not a widespread problem. However, EPA did determine that systems
needed more guidance for collecting samples and calculating the lead 90th percentile to
determine compliance with the rule. In November, EPA issued guidance to clarify
requirements for lead sampling and calculating compliance. As part of its effort to address
compliance issues, EPA has offered workshops to improve water system compliance, and
issued new guidance to states to improve implementation and enforcement of the rule.
As with other drinking water regulations, an issue central to effective implementation
of the lead rule is the need for cities to upgrade their water infrastructure. S. 2550, a water
infrastructure funding bill reported in the 108th Congress, included provisions to address
lead contamination. Similarly, consideration of this issue in the 109th Congress could
occur in tandem with discussions of water infrastructure financing legislation. (See also,
CRS Issue Brief IB10118, Safe Drinking Water Act: Implementation and Issues.)
10 Centers for Disease Control and Prevention, “Blood Lead Levels in Residents of Homes with
Elevated Lead in Tap Water,” pp. 268-270.