Drinking Water: Approaches For Identifying Lead Service Lines Should Be Shared With All States

The crisis in Flint, Michigan, brought increased attention to lead in drinking water infrastructure. Lead in drinking water primarily comes from corrosion of service lines connecting the water main to a house or building. In 1991, EPA issued the Lead and Copper Rule that required water systems to conduct a “materials inventory” of lead service lines. In light of the events in Flint, EPA sent a letter to all states in February 2016 encouraging them to work with water systems to publicly post the materials inventory, along with any additional updated maps or inventories of lead service linesactions the rule does not require.

A House Committee report accompanying a bill for the Department of the Interior, Environment and Related Agencies Appropriations Act, 2017, includes a provision for GAO to review lead service lines. This report examines (1) what is known about the number of existing lead service lines among states and water systems and (2) states' responses to EPA's February 2016 request to work with water systems to publicize inventories of lead service lines and any steps EPA has taken to follow up on these responses. GAO reviewed existing studies of lead service lines, reviewed the websites of the 100 largest water systems, and interviewed EPA officials in headquarters and its 10 regional offices.

The total number of lead service lines is unknown and while national, state, and local estimates exist, approaches used to count lead service lines vary. A 2016 American Water Works Association study estimated that nationally there were 6.1 million lead service lines, but the study has significant sampling limitations and, as a result, likely does not accurately reflect the total number of lead service lines nationwide. In addition, at least two statesMassachusetts and Washingtonpublished reports with estimates of lead service lines and reported 22,023 and 1,000-2,000 lead service lines as of 2016 and 2017, respectively. Certain water systems also have estimates, such as the approximately 7 percent of publicly owned lead service lines out of the area's total number of service lines cited by a representative for the system serving Cincinnati, Ohio and surrounding areas, as of May 2018.

While most states informed the Environmental Protection Agency (EPA) that they intend to fulfill the agency's request to publicize inventories of lead service lines, EPA has identified potential challenges to these efforts. Of the approximately 43 states that responded that they would fulfill EPA's request, almost all (39) reported to EPA that, although they had encouraged water systems to publicize inventories, few systems had completed these actions. GAO found in January 2018 that, of the 100 largest water systems, 12 had publicized information on the inventory of lead service lines. According to EPA, among challenges in conducting inventories of lead service lines and publicizing information about lead service lines were concerns about posting on public websites information about lead service lines on private property; and a lack of records about the locations of lead service lines. EPA told GAO the agency was focused on state compliance with drinking water rules, and not following up with information on how states could address the challenges cited. By sharing information with all states about the approaches that some states and water systems are using to successfully identify and publicize information about lead service lines, including responses to potential challenges, EPA could encourage states to be more transparent to the public and support the agency's objectives for safe drinking water.

GAO recommends that EPA share information about the successful approaches states and water systems use to identify and publicize locations of lead service lines with all states. EPA agreed with the recommendation.

The crisis in Flint, Michigan, brought increased attention to the country’s  challenge of addressing lead in drinking water infrastructure. According to  the U.S. Environmental Protection Agency (EPA) and others, there is no  level of lead that is safe in drinking water. Lead poses the greatest risk to  infants, children under the age of 6, and pregnant women. In children, it  can delay growth, cause learning and behavioral problems, and lower IQ,  while in pregnant women it can reduce fetal growth and cause premature  birth. Lead in drinking water primarily comes from the corrosion of pipes  (such as service lines made of lead) that connect the drinking water main  (a primary pipeline) to a house or building. The corrosion results from a  chemical interaction between water and pipes that wears the metal and  allows lead to dissolve or lead particles to flake away over time. Other  sources of lead in drinking water include solder that connects pipes, and  fixtures made with lead or with brass that contains lead.

Lead was widely used in plumbing materials, including service lines, until  1986 when the Safe Drinking Water Act (SDWA) was first amended to  generally prohibit the new installation of lead pipes and solder. According  to EPA, homes built before 1986 are more likely to have lead pipes,  solder, and fixtures. Consequently, these homes are a priority for  monitoring under EPA’s Lead and Copper Rule, which minimizes the  amount of lead in the nation’s drinking water supply. As of December  2016, the approximately 68,000 drinking water systems covered by the  Lead and Copper Rule served about 312 million peoplemost of the U.S.  population. When the Lead and Copper Rule was promulgated in 1991, it  required all covered drinking water systems to collect information about  the infrastructure that delivered water to customers, including any known  lead pipes and lead service lines. The purpose of this effort referred to  as materials evaluation (hereafter materials inventory)was to identify  locations that may have been particularly susceptible to high lead or  copper concentrations, from which water systems would collect drinking  water samples. According to 2010 EPA guidance, in developing the  materials inventory, water systems should survey all records documenting  the materials used to construct and repair the drinking water distribution  system and buildings connected to the system.

In a January 2016 letter to Michigan’s Governor, EPA noted its concern  with lack of transparency and accountability to the public in Flint. In light  of events in Flint and other U.S. cities, EPA sent a letter to all state  environmental commissioners in February 2016 requesting near-term  actions to assure the public that EPA and the states were working  together to address risks from lead in drinking water, and to increase  transparency in water systems’ implementation of the Lead and Copper  Rule. In this letter, EPA encouraged states to work with water systems to  post, on a public website, the water system’s original materials inventory  along with any additional updated maps or inventories of lead service  linesactions the Lead and Copper Rule does not require. EPA also  encouraged states to place an emphasis on large water systems, which  EPA regulations define as those serving populations greater than  50,000.

House Report No. 114-632, accompanying a bill for the Department of the  Interior, Environment, and Related Agencies Appropriations Act, 2017,  includes a provision for us to review the number of lead service lines.  Our objectives were to examine (1) what is known about the number of  existing lead service lines nationally, and among states and water  systems; and (2) states’ responses to EPA’s February 2016 request to  work with water systems to publicize inventories of lead service lines and  any steps EPA has taken to follow up on these responses. This report  addresses lead in drinking water, not other sources of lead such as paint,  paint chips, dust, toys, or food.

To examine what is known about the number of existing lead service lines  nationally, and among states and water systems, we reviewed existing  studies and other documents regarding the extent of and experience with  such lines. We found three written studies with estimates of lead service  lines—one using national data and two that were state-specific. We took  a number of steps, including conducting interviews with each study’s  authors, to examine the reliability of the data used in the studies. For the  one study we reviewed that used national data, the data were of  undetermined reliability because the sample of water systems included in  the study was not generalizable to all water systems and the authors  could not verify the accuracy of the information provided by water  systems. Appendix I provides more information on our reasons for  designating the data as undetermined reliability. For the two state-specific  studies, we determined that the data represented reasonable efforts to  estimate the number of lead service lines, although the states also could  not verify the accuracy of the information provided by water systems.  Therefore, we also found these estimates to be of undetermined  reliability. Appendix I provides more information on our reasons for  designating the data as undetermined reliability. We did not find any  studies with information comparing the quality of estimates among water  systems. However, we interviewed representatives of the Greater  Cincinnati Water Works water system about their estimate and found the  data to be sufficiently reliable for the purpose of describing their reported  best available estimate. We also interviewed EPA staff about their  knowledge of estimates provided by states and water systems; and  subsequently interviewed officials in some of these states, namely  Massachusetts, Ohio, and Washington. We also interviewed  representatives of water organizations to identify potential studies and  other sources of information about the number of lead service lines. We  selected these organizations based on their knowledge of conducting  inventories of lead service lines as a part of the process for replacing  such lines.

To examine states’ responses to EPA’s request and any steps EPA has  taken to follow up on these responses, we reviewed the websites of the  100 largest water systems (by population served) to identify which water  systems have made the information available to the public. We used a  structured process to review each website for the presence or absence of  such information so that we could reliably tabulate the results. We also  conducted an in-depth, semi-structured interview with representatives  from the Greater Cincinnati Water Works about their experiences in  mapping lead service lines and providing the information to the public. We  selected this water system based on the extent of its mapping initiative  and based on recommendations from EPA and several nonprofit and  water advocacy organizations. The results of this interview are not  generalizable to other water systems but provide illustrative examples.  We also conducted semi-structured interviews with officials in EPA’s  headquarters and all 10 of its regional offices. Finally, we compared  EPA’s actions to follow up on state responses with federal standards for  internal control for information and communication.

We conducted this performance audit from October 2017 to September  2018 in accordance with generally accepted government auditing  standards. Those standards require that we plan and perform the audit to  obtain sufficient, appropriate evidence to provide a reasonable basis for  our findings and conclusions based on our audit objectives. We believe  that the evidence obtained provides a reasonable basis for our findings  and conclusions based on our audit objectives.

Generally, the responsibility for reducing lead in drinking water and  ensuring safe drinking water overall is shared by EPA, states, and local  water systems. EPA is responsible for, among other things, national  implementation of the Lead and Copper Rule, setting standards,  overseeing states’ implementation of the rule, and conducting some  enforcement activities. However, most states have primary responsibility  for enforcing the requirements under SDWA as amended. Water  systems are generally subject to requirements under SDWA as amended,  such as the Lead and Copper Rule, and are responsible for managing  and funding the activities and infrastructure needed to meet those  requirements.

Such infrastructure includes storage facilities and drinking water mains  and may include other pipes such as service lines. There are 1 million  miles of drinking water mains in the country, according to a 2017  American Society of Civil Engineers study. As figure 1 illustrates,  service lines are the smaller pipes that connect the water mains to homes  and buildings. According to EPA guidance, service lines also include any  smaller pipes used for connecting a service line to the water mains (e.g.,  gooseneck pipes which are also known as pigtails). Service lines can  generally be made of lead, steel, copper, or plastic. Service lines can be  fully owned by the water system (publicly owned) or by the homeowner  (privately owned), or ownership can be shared. In most communities, lead  service lines are partially owned by the water system and partially owned  by the homeowner. With shared ownership, the water system typically  owns the service line from the water main to the curb stop, and the  homeowner owns the service line from the curb stop into the home. In  such cases, each party is responsible for maintaining the part of the  service line that it owns.

In some circumstances, if lead levels are higher than the Lead and  Copper Rule allows and other measures do not alleviate the problem, the  Lead and Copper Rule requires water systems to replace lead service  lines under the systems’ control. The Lead and Copper Rule does not  require homeowners to replace the portion of lead service lines they own,  but if they choose to do so they are generally responsible for the  associated costs. The Lead and Copper Rule allows for a partial  replacement by the water system when an owner of a home or building is  unable or unwilling to pay for replacement of the portion of the service line  not owned by the water system.

The Total Number of Lead Service Lines Is Unknown, and National, State, and Local Estimates Vary

The total number of lead service lines is unknown and while national,  state, and local estimates exist, approaches used to count lead service  lines vary. The total number of lead service lines is unknown because,  among other things, the Lead and Copper Rule does not require all water  systems to collect such information. National, state, and local estimates  exist, but the methods used to arrive at these estimates vary, making it  challenging to compare estimates.

The Lead and Copper Rule Does Not Generally Require Water Systems to Maintain Complete Information about Lead Service Lines or Report Such Information to EPA

The total number of lead service lines is unknown, in part because the  Lead and Copper Rule does not require all water systems to develop and  maintain a complete inventory of lead service lines, and there are no  national repositories of information about lead service lines. According to  EPA headquarters officials we interviewed in 2017, the materials  inventory required under the Lead and Copper Rule is not intended to be  a census of lead service lines (and other lead pipes such as goosenecks/  pigtails). Instead, it is intended to provide sufficient information to develop  a plan for periodically obtaining tap samples. For example, according to  2008 EPA guidance to water systems, if a system contains lead service  lines, then, if possible, half of the sample sites should include those  served by a lead service line.

The Lead and Copper Rule requires water systems to conduct complete  inventories only if the water system is required to begin replacing lead  service lines. In these instances, water systems are required to expand  the materials inventory to a complete inventory that identifies the total  number of lead service lines for the purpose of tracking replacements  over time. As we reported in 2017, based on the available data, the  majority of the 68,000 water systems subject to the Lead and Copper  Rule at the time of our review had not been required to replace lead  service lines and therefore were not required to conduct complete  inventories.

Moreover, there are no national repositories for information about lead  service lines. In September 2017, we recommended that, as a part of  revisions to the Lead and Copper Rule, EPA require states to report data  on lead pipes (including lead service lines) and incorporate these data in  the agency’s Safe Drinking Water Information System. EPA agreed with  the recommendation but has not implemented it. In May 2018, EPA noted  that it was in the process of reviewing comments received through  consultations with state and local officials and tribes. According to EPA  officials, final revisions to the Lead and Copper Rule are expected by  February 2020. We continue to believe that EPA should collect data  about lead pipes (including lead service lines) from states. By doing so,  EPA and congressional decision makers would have important  information at the national level on what is known about lead  infrastructure in the country, thereby facilitating oversight of the Lead and  Copper Rule.

National, State, and Local Estimates of Lead Service Lines Exist, and Those We Reviewed Had Significant Limitations; but the Methods Used to Arrive at These Estimates Vary

The total number of lead service lines is unknown, and while some  entities have developed estimates of lead service lines at the national,  state, or local water system level, the estimates we reviewed have  significant limitations to their reliability. Moreover, the approaches used to  arrive at these estimates vary, making it challenging to compare  estimates. Nationally, according to EPA’s October 2016 Lead and Copper  Rule Revisions White Paper, there are an estimated 6.5 million to 10  million homes served by lead service lines. This range of estimates,  based in part on data from a study for the 1991 Lead and Copper Rule,  has significant limitations. In appendix I we explain why EPA’s estimate  may not accurately reflect the total number of lead service lines,  nationwide.

An April 2016 American Water Works Association study estimated 6.1  million lead service lines nationwide. The authors of this study  extrapolated the number based on survey responses from 978 water  systems in 2011 and 2013. While this study is the most recent attempt to  provide a national estimate, it has significant limitations. First, the sample  was not statistically representative of all 68,000 water systems subject to  the Lead and Copper Rule. Rather, the water systems that responded to  the American Water Works Association’s survey are not a statistical  sample. Second, according to the study’s authors, survey responses were  based on water systems’ best guesses of the number of lead service lines  in their systems. However, since water systems have not been required to  maintain inventories of lead service lines, many of them do not know the  exact number. For these reasons, we are not confident that the number  accurately reflects the total number of lead service lines nationwide.

An American Water Works Association official told us that the  organization is not planning to update the study. EPA officials told us that  they were not aware of a more recent study than the association’s 2016  study. In addition, EPA officials said in May 2018 that the results in the  American Water Works Association study likely represent a lower-bound  estimate for the number of lead service lines in the country because the  sample was not generalizable, and had other data quality issues. EPA  officials in one region we interviewed said that estimates of lead service  lines can decrease or increase as a water system replaces lead service  lines and as a water system does or does not count lead service lines on  private property.

The Lead and Copper Rule does not require states to collect statewide  information about lead service lines, but at least two states collected data  from water systems in their states and published reports with these data:

A 2016 report by the Massachusetts Department of Environmental Protection’s Drinking Water Program reported 22,023 lead service lines and 15,809 lead goosenecks and pigtails statewide. The report counted goosenecks and pigtails separately from lead service lines. Officials from the Massachusetts Department of Environmental Protection told us that the state has about 2 million service lines total; therefore, about 1 percent of the total service lines are lead.

A 2017 report by the Washington State Department of Health estimated 1,000-2,000 lead service lines statewide and 8,000 goosenecks statewide. According to Washington State officials, they continued to update their estimates in early 2018 with selected water utilities.

Generally, the purpose of both studies, as stated in each report, was to  identify areas in which water systems would need technical assistance in  complying with the Lead and Copper Rule or state requirements.  However, for the purposes of estimating the number of lead service lines,  complete details were not available about the methodologies and some  systems that did respond were only able to provide rough guesses rather  than precise counts of lead service lines. EPA headquarters officials told  us that Massachusetts and Washington were at the forefront of states’  efforts to gather information about lead service lines. EPA officials also  told us that they were not aware of any other states with published reports  estimating the number of lead service lines. However, at least two states  have also collected information about lead service lines but have not  published the information in official reports, at the time of our review. For  example, in 2016, officials in Indiana and Maryland sent questionnaires to  water systems in their states asking for information about the number of  lead service lines.

A representative of a water association told us that, generally, water  systems were in the beginning stages of conducting complete inventories  of lead service lines. However, some local water systems also have  estimates. For example, EPA officials told us that water systems in the  states of Ohio, Michigan, and Washington had estimates of lead service  lines. In May 2018, a representative of the Greater Cincinnati Water  Works water system estimated there were approximately 7 percent of  publicly owned and approximately 18 percent privately owned lead  service lines out of a total of 240,000 service lines in the area served by  that water system. In March 2018, representatives of the Greater  Cincinnati Water Works water system said that their estimates of lead  service lines are best characterized as what is known at any given point  in time. These representatives also told us that they collect this  information on a continual basis from historical and on-going maintenance  records, reports of lead service lines by customers, and the water  system’s lead service line replacement program, among other sources.

To conduct complete inventories and develop estimates, water systems  have used varying approaches, which can hinder comparisons among  states and water systems. The publicly available reports that existed as of  May 2018 provide some insight into the various approaches water  systems have used. For example, to identify lead service lines, water  systems have used visual inspection or a combination of visual  inspections, existing water system records, and discussions with  homeowners. In addition, water systems have used various definitions of  lead service lines. For example, water systems have counted:  only active service lines delivering water to customers, or both active and inactive (no longer delivering water to customers) service lines; or only the publicly owned lead service lines, or both the publicly and privately owned portions of the lead service lines; or only lead service lines or the lead service lines and goosenecks/pigtails separately.

Most States Reported Fulfilling EPA’s Request, but Potential Challenges Remain that EPA Information Sharing Could Help to Address

While most states informed EPA that they intend to fulfill the agency’s  request to work with water systems to publicize inventories of lead service  lines, EPA has identified potential challenges to these efforts.  Nonetheless, the agency has not followed up with all states since 2016 to  share information about how to address these challenges. Most states  that said they intended to fulfill EPA’s request to encourage water  systems to publicize materials inventories reported in subsequent letters  to or meetings with EPA that they did so; however, as of May 2018, most  large waters systems had not made such information public.

Most States Reported Fulfilling EPA’s Request to Encourage Water Systems to Publicize Materials Inventories, but Most Large Water Systems GAO Reviewed Did Not Do So

Our analysis of states’ written responses to EPA’s 2016 request, and  information obtained through interviews with EPA officials as of February  2018, found that most (43) of the 50 states indicated an intent to fulfill  EPA’s request, 3 states said that they may consider it, and 4 states did  not intend to fulfill EPA’s request. Of the approximately 43 states that  responded that they would fulfill EPA’s request, almost all (39) reported in  subsequent letters to or meetings with EPA that they had encouraged  water systems to publicize their materials inventories or other information  about lead service lines. In these letters and meetings, states also  reported taking other actions to increase their knowledge about lead  service lines such as requesting that water systems update the materials  inventory required by the Lead and Copper Rule, creating online  repositories of maps of lead service lines, posting reports on lead service  lines, and issuing requirements for water systems to collect information  on lead service lines. For example, in May 2016, the governor of  Washington issued a directive requiring the state’s Department of Health  to work with certain water systems to identify all lead service lines and  lead components within 2 years. Figure 2 shows the number of states that  reported fulfilling EPA’s request or taking other related actions.

Because EPA asked states to prioritize large water systems (those  servicing populations greater than 50,000), we reviewed the websites for  the 100 largest water systems. As of January 2018, we found 12 of these  water systems had publicized information on the inventory of lead service  lines; the rest had not. The information on the websites for the 12 water  systems varied. For example, the water system for Tulsa, Oklahoma  posted a map that highlighted where lead service lines may be present.  Water systems such as Cincinnati, Ohio, Boston, Massachusetts, and  Washington, D.C., provided interactive maps that showed locations  identified as having lead service lines. See figure 3 for examples of the  interactive maps of lead service lines that some selected large water  systems have provided to the public. Water systems that serve  populations greater than 50,000 but were not among the 100 largest  water systems at the time of our review may have also publicized  information on the inventory of lead service lines. For example, the water  systems for Akron, Ohio, Flint, Michigan, and Providence, Rhode Island  each publicized an interactive or other type of map of lead service lines.

EPA Identified Potential Challenges to Publicizing Materials Inventories but Has Not Followed Up with All States about How to Address Such Challenges Since 2016

EPA officials in the regional offices provided a range of reasons why  water systems may be challenged in conducting inventories of lead  service lines and making any information about lead service lines public,  however, it has not followed up with all states about how to address such  challenges since 2016. In September 2017, we reported that the six  states that would not fulfill EPA’s 2016 request had highlighted challenges  in finding historical documentation about lead pipes to create plans for  collecting tap water samples or in dedicating staff resources to do so. In  January and February 2018, some officials whom we interviewed in  EPA’s 10 regional offices agreed that these would be challenges for  states and water systems. The officials also mentioned additional  potential challenges in conducting complete inventories of lead service  lines or publicizing information about lead service lines. Table 1 describes  the challenges mentioned by EPA officials in the 10 regional offices.

Since the February 2016 letter, EPA followed up in July 2016 with a letter  to the Association of State and Territorial Health Officials and  Environmental Council of States, which represents all states. In that letter,  EPA provided two examples of state practices that increase public  transparency: some drinking water systems are providing online  searchable databases that provide information on known locations of lead  service lines, or are providing videos that show homeowners how to  determine whether their home is served by a lead service line.  The  letter also said that EPA would continue to work with states to ensure that  the identification of the locations of lead service lines remains a priority for  drinking water systems.

However, EPA has conducted limited follow-up since then, mainly, EPA  headquarters and regional officials said, because they have focused their  efforts on ensuring states appropriately comply with the Lead and Copper  Rule. As previously noted in this report, posting materials inventories or  other information about the location of lead service lines is not a  requirement of the Lead and Copper Rule. In May 2018, EPA  headquarters officials we interviewed said that they learned of some  states’ and water systems’ efforts toward making information about lead  service lines available to the public since 2016, through conferences and  discussions with states. These headquarters officials told us that they  have shared such efforts with those states who, in 2016, said they did not  intend to fulfill EPA’s 2016 request. For example, EPA shared how states  that were publicizing information about lead service lines were addressing  privacy concerns with states that originally said they would not fulfill  EPA’s request. However, as of January 2018, most of the 100 largest  water systems had not made their materials inventories or additional  maps or updated inventories public. According to EPA’s February 2016  letter, the agency’s objective in encouraging states to work with water  systems to post, on a public website, the water system’s original materials  inventory along with any additional updated map or inventories of lead  service lines was to assure the public that lead risks were being  addressed. Under federal standards for internal control, management  should externally communicate the necessary quality information, so that  external parties can help to achieve the entity’s objectives. By sharing  information with all states about the approaches that some states and  water systems are using to successfully identify and publicize information  about lead service lines, including responses to potential challenges, EPA  could encourage states to be more transparent to the public and support  the agency’s objectives for safe drinking water.

Lead service lines present a significant risk of lead contamination in  drinking water. Publicizing drinking water systems’ knowledge about lead  service lines, and other lead infrastructure, would facilitate oversight of  the Lead and Copper Rule. In September 2017, we recommended that,  as a part of revisions to the Lead and Copper Rule expected by February  2020, EPA require states to report data on lead pipes (including lead  service lines) and incorporate these data in the agency’s Safe Drinking  Water Information System. EPA agreed with the recommendation, and  we continue to believe that EPA should require data about lead pipes  (including lead service lines) from states. Most states reported that they  had encouraged their water systems to publicize information about lead  service lines in response to EPA’s February 2016 requests. EPA  headquarters officials told us that they had learned of some states’ and  water systems’ efforts since 2016 and shared this information with the few  states that said that they would not take action in response to EPA’s  letter. This information did in fact help at least one state take action,  according to information we received from EPA and the state. By sharing  information with all states about the approaches that some states and  water systems are using to successfully identify and publicize information  about lead service lines, including responses to potential challenges, EPA  could encourage states to be more transparent to the public and support  the agency’s objectives for safe drinking water.

The Assistant Administrator for Water of EPA’s Office of Water should  share information with all states about the approaches that some states  and water systems are using to successfully identify and publicize  information on lead service lines, including responses to potential  challenges. (Recommendation 1)

We provided a draft of this report to EPA for review and comment. In its  comments, reproduced in appendix II, EPA agreed with our  recommendation. The agency also highlighted a recently developed  website that showcases efforts to identify and replace lead service lines  and said that it will continue to ensure states and water systems are  aware of this resource.

We are sending copies of this report to the appropriate congressional  committees, the Administrator of EPA, and other interested parties. In  addition, the report is available at no charge on the GAO website at  http://www.gao.gov.

If you or your staff members have any questions about this report, please  contact me at (202) 512-3841 or gomezj@gao.gov. Contact points for our  Offices of Congressional Relations and Public Affairs may be found on  the last page of this report. Key contributors to this report are listed in  appendix III.

Appendix I: Objectives Scope and Methodology

Our objectives were to examine (1) what is known about the number of  existing lead service lines nationally, and among states and water  systems; and (2) state responses to EPA’s February 2016 request to  work with water systems to publicize inventories of lead service lines and  any steps EPA has taken to follow up on these responses.

To examine what is known about the number of existing lead service lines  nationally, and among states and water systems, we relied on interviews  and publicly available reports for which we could assess the reliability of  the data. We reviewed the requirements under the Lead and Copper Rule  for assessing the number of lead service lines. We interviewed officials  from EPA’s Office of Water and the following water organizations  concerning what these officials knew about the number of lead service  lines nationally and among states and water systems: the American  Water Works Association, Association of State Drinking Water  Administrators, and Regional Community Assistance Partnership. We  also interviewed an official with the Environmental Defense Fund  regarding the available information about the number of lead service lines  nationally and among states and water systems. We selected these  organizations because they are all members of the Lead Service Line  Replacement Collaborative, a consortium that provides information about  voluntary lead service line replacement for states and water systems. On  behalf of the Lead Service Line Replacement Collaborative, the  organizations we spoke with are collecting examples of states’ and water  systems’ experiences in conducting inventories of lead service lines, as  the first step in replacing lead service lines. Using information from these  interviews, we identified three published studies from the American Water  Works Association, the state of Massachusetts, and the state of  Washington. We interviewed the authors of the studies to determine the  reliability, completeness, and accuracy of the data presented in the  studies.

For the 2016 American Water Works Association study, we determined  that the data were of undetermined reliability because the responses of  the water systems surveyed were not generalizable to all water systems  and the study authors could not verify the accuracy of the information.  Specifically, the sample in the 2016 American Water Works Association  study was not based on a statistical sample, and therefore the sampling  error was not calculated and information was not available to determine  whether responding water systems were similar to nonresponding water  systems. For example, the estimate is based on survey responses from  978 of the approximately 23,000 water systems that existed around the  time of the surveys, and therefore may not represent all water systems  nationwide. In addition, since many water systems do not have complete  inventories of their lead service lines, the accuracy of data that water  systems submitted in response to the survey is difficult to verify. For  example, our interview with the study authors indicates that the  information provided by water systems varied in quality, with some  systems basing their responses on rough estimates. We based our  determination about the data using the criteria of Total Survey Error,  which is a framework for assessing the validity and reliability of survey  estimates. It includes sampling error (the difference between the  population and the sample), nonresponse error, measurement error (the  difference between the true response and the response provided by the  respondent) and coverage error (the discrepancy between the list of  individuals that is used to select a sample and the target population).  EPA’s 2016 Lead and Copper Rule Revisions White Paper also identified  an estimate of lead service lines. According to EPA officials, this estimate  used data from the 2016 American Water Works Association study and a  1988 American Water Works Association study cited in the regulatory  impact analysis for the 1991 Lead and Copper Rule. The 1991 estimate  also had significant limitations in measurement error and representation  error as well as a lack of documentation about key aspects of the  methodology. As such, we determined the estimate was not reliable for  the purposes of establishing the total number of lead service lines in  existence as of 1991.

The two state-specific studies represent reasonable efforts to estimate  the number of lead service lines in these states. However, they generally  could not verify the accuracy of the information provided by these  systems because, as we note elsewhere in this report, water systems  may not know the number of lead service lines they have. Therefore, for  the state-specific studies, we also determined that the data were also of  undetermined reliability. Finally, while the Greater Cincinnati Water Works  water system did not publish a report about lead service lines, we  collected the information through an in-person interview and corroborated  the information through a review of the water system’s geographic  information system database. The Greater Cincinnati Water Works’ GIS  database includes the location and material information for all of the water  system’s distribution system. According to the Greater Cincinnati Water  Works website, the water system continues to update its map as it  obtains more information from its customers. Based on these steps we  deemed the data provided by the water system to be sufficiently reliable  for the purposes of describing the estimate reported by representatives of  the Greater Cincinnati Water Works system.

To examine states’ responses to EPA’s February 2016 request to work  with water systems to publicize inventories of lead service lines and any  steps EPA has taken to follow up on these responses, we relied both on  the publicly available letters from each state to EPA and on interviews  with EPA regional and headquarters officials. We did not interview state  officials in all 50 states, but reviewed some state documents, where  available. We used a standard set of open-ended questions to interview  officials in EPA’s headquarters and in each of the 10 regional offices. To  analyze states’ and EPA officials’ responses, we conducted two analyses.  Specifically, we conducted two analyses to summarize updates in state  responses to EPA’s February 2016 letter and EPA’s responses to  challenges states and water systems may face in conducting and  publicizing materials inventories. To confirm each analysis, one analyst  independently summarized the information and another analyst verified  the accuracy of the information. All initial disagreements were discussed  and reconciled. All numbers in our analysis are considered approximate  because interpretations of the states’ responses to EPA’s 2016 letter can  differ, and states may have taken actions after our interviews with EPA  regional officials, or may have taken actions that they did not report to  EPA. Figure 4 shows the EPA regions and the states within those  regions. We also reviewed EPA documents related to EPA’s request that  states take certain actions following the events in Flint, Michigan. In  addition, we reviewed federal regulations; EPA guidance to water  systems on how to implement the Lead and Copper Rule; and other  relevant documents such as an EPA white paper.

Because EPA asked states to place an emphasis on working with large  water systems to publicize their materials inventories or updated  inventories or maps of lead service lines, we reviewed the websites of the  100 largest water systems by population. Our review was conducted in  January to February 2018; and since then, additional water systems may  have provided information to the public on lead service lines. We  identified the largest water systems, based on population served, from  data in EPA’s Safe Drinking Water Information System/Fed. EPA has  stated on its website that the agency acknowledges challenges related to  the data in the Safe Drinking Water Information System/Fed, specifically  underreporting of some data by states. GAO has also reported on EPA’s  challenges with the Safe Drinking Water Information System/Fed. Even  with these challenges, the information on the populations served by water  systems in the Safe Drinking Water Information System/Fed is generally  reliable. We used a standard set of search terms on each website to  ensure the consistency of our searches, as well as information from water  organizations and EPA officials, where applicable. We counted a water  system as having an inventory if the water system provided a map,  interactive map, list of pipes or service lines, or numerical count of lead  service lines available to the public. To ensure the completeness of this  analysis, one analyst independently conducted the search of websites  and another analyst verified the search. All initial disagreements were  discussed and reconciled. We compared EPA’s actions to follow up on  state responses with federal standards for internal control for information  and communication.

Appendix II: Comments from the U.S. Environmental Protection Agency

Appendix III: GAO Contact and Staff Acknowledgments

In addition to the contact named above, Diane Raynes (Assistant  Director); Tahra Nichols (Analyst in Charge); David Blanding, Jr.; Mark  Braza; Lawrence Crockett, Jr.; Justin Fisher; Richard P. Johnson, and  Jeanette Soares made key contributions to this report. In addition,  Cynthia Norris and Dan Royer made important contributions.

Drinking Water: Additional Data and Statistical Analysis May Enhance  EPA’s Oversight of the Lead and Copper Rule. GAO-17-424.  Washington, D.C.: September 1, 2017.

Water Infrastructure: Information on Selected Midsize and Large Cities  with Declining Populations. GAO-16-785. Washington, D.C.: September  15, 2016.

Water Infrastructure: EPA and USDA Are Helping Small Water Utilities  with Asset Management; Opportunities Exist to Better Track Results.  GAO-16-237. Washington, D.C.: January, 27, 2016.

Drinking Water: Unreliable State Data Limit EPA’s Ability to Target  Enforcement Priorities and Communicate Water Systems’ Performance.  GAO-11-381. Washington, D.C.: June 17, 2011.

Drinking Water: The District of Columbia and Communities Nationwide  Face Serious Challenges in Their Efforts to Safeguard Water Supplies.  GAO-08-687T. Washington, D.C.: April 15, 2008.

Drinking Water: EPA Should Strengthen Ongoing Efforts to Ensure That  Consumers Are Protected from Lead Contamination. GAO-06-148.  Washington, D.C.: January 4, 2006.

District of Columbia’s Drinking Water: Agencies Have Improved  Coordination, but Key Challenges Remain in Protecting the Public from  Elevated Lead Levels. GAO-05-344. Washington, D.C.: March 31, 2005.

Drinking Water: Safeguarding the District of Columbia’s Supplies and  Applying Lessons Learned to Other Systems. GAO-04-974T.  Washington, D.C.: July 22, 2004.

The water crisis in Flint, Michigan, highlighted dangers of lead in drinking water infrastructure. Lead enters drinking water primarily from old service lines between water mains and houses or buildings. The total number of lead service lines across the country is unknown.

EPA asked states to publicize information about known locations of lead service lines. However, we found most of the largest water systems have not done so.

We recommended that EPA share information on approaches for counting lead service lines with all states.