Lead in drinking water comes primarily from corrosion of service lines that connect the water main to a building. The total number of lead service lines in the United States is unknown. Through our statistical analysis of 4 water systems' geospatial lead data and U.S. Census data, we found that areas with older housing and vulnerable populations were more likely to have lead service lines. Many wa...

Extreme weather related to climate change potentially threatens utilities that produce drinking water and treat wastewater. We examined federal technical and financial assistance to make such infrastructure more resilient to extreme weather and asked experts about additional options. For example, EPA provides technical assistance to utilities to improve resilience. However, EPA’s program is sm...

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...

Activities, such as hydropower and agricultural practices, have impaired water quality in parts of the Columbia River Basin. This has put human health at risk and threatened the existence of some species, such as salmon. Federal and state agencies, tribes and others have taken steps to improve Basin water quality. However, the U.S. Environmental Protection Agency and the Office of Management and...

The San Francisco Bay Delta watershed supplies drinking water to 25 million people and irrigation for about half the nation's fruit and vegetable production. Federal and nonfederal entities carry out activities to protect and restore the watershed, which has seen declines in water quality, flood protection, and habitat. We found federal agencies are not all using their plan to coordinate restorat...

Puget Sound is the nation's second largest estuary, supporting millions of people and a wide variety of species. Development and use, however, have degraded its water quality and habitat, and harmed critical species like salmon and killer whales. Federal and nonfederal entities have established two main interagency groups to coordinate restoration efforts. However, it's difficult to assess the am...

Long Island Sound, an estuary in one of the nation's most densely populated areas, provides many economic and recreational benefits. However, development and pollution have degraded water quality and led to hypoxia, low levels of dissolved oxygen that increase mortality of fish and other species. A federal-state partnership funded restoration projects and created a plan and cost estimates to rest...

We surveyed school districts across the country on testing for lead in drinking water in 2017. Based on our nationally generalizable survey, we estimate that: 41% of districts, serving 12 million students, had not tested for lead in the 12 months before completing our survey. 43% of districts, serving 35 million students, tested for lead. Of those, 37% found elevated levels and reduced or elimin...

Stormwater from streets and sewers can flow into rivers and be a major source of pollution. EPA requires cities and utilities to reduce this type of pollution. Traditional remedies can be expensive for local communities but green infrastructure can be a less expensive option. Green infrastructure uses natural processes and materials (like green roofs) to slow stormwater so it is absorbed and filt...

No level of lead is safe in drinking water. Lead accumulates in the body over time, causing long-lasting effects, particularly for children and pregnant women. The Lead and Copper Rule generally requires water systems to test for lead and treat water to help prevent corroded pipes from leaching lead into the water. The 68,000 water systems serving the majority of U.S. residents are subject to the...

Harmful overgrowths of algae—called algal blooms—are a problem in all 50 states. These blooms can hurt aquatic plants and animals by producing toxins, consuming oxygen, and limiting light penetration in the water. People who eat affected seafood, drink the contaminated water, or breathe airborne droplets can get sick or even die. These blooms can also hurt the seafood industry, recreation, and...

The Environmental Protection Agency (EPA) has implemented all of the recommendations GAO made in its May 2011 report to improve the Unregulated Contaminant Monitoring Rule (UCMR) program. In that report, GAO recommended that EPA (1) monitor for the full 30 contaminants allowed by statute, (2) monitor for most or all contaminants using a more robust monitoring approach, and (3) select sufficiently...

The Environmental Protection Agency (EPA) and the states each have responsibilities for developing and implementing pollution targets, known as total maximum daily loads (TMDL). EPA oversees states' TMDL efforts by establishing in regulations minimum requirements TMDLs need for approval, providing funding, and furnishing technical assistance. States develop TMDLs and generally take the lead in imp...

"Internet of Things" technology refers to devices collecting information, communicating it to a network and, in some cases, completing a task—like unlocking doors using a smartphone application. Many agencies use this technology to control equipment, monitor building systems, or perform other tasks. For example, the Environmental Protection Agency uses sensors on buoys to monitor water quality a...

The U.S. Section of the International Boundary and Water Commission manages two wastewater treatment plants along the U.S.-Mexico border that treat raw sewage, mostly from Mexico. But population growth and aging plant infrastructure allow stormwater to bring bacteria, trash, and sediment from Mexico into the U.S.—affecting public health and the environment in Arizona and California. The Commiss...

Do military installations have enough water to meet mission needs? DOD completed 6 assessments—3 at the department level and 3 at the military-service level—and found 102 installations at risk of water scarcity. But these assessments were conducted differently and produced different results. The department-level assessments didn’t follow leading practices, and officials disagreed over wheth...

Nitrogen and phosphorus naturally occur in water bodies such as rivers and lakes. Wastewater from factories and runoff from streets and farms can add more of these nutrients to water bodies, degrading water quality. Some states limit the amount of nutrients that certain pollution sources can discharge. Eleven states have "credit trading" programs that allow sources to meet their limits by buying...

Through our work, we've made numerous recommendations to EPA about its management and operations, as well as its programs related to water issues; environmental contamination and cleanup; toxics, chemical safety, and pesticides; public health and environmental justice; and air quality, climate change, and energy efficiency. We testified that, as of August 23, 2017, EPA had implemented 191 of 318...

Agricultural production can have harmful effects on natural resources, such as when animal waste runs off into waterways. Conservation practices like installing structures to store animal waste can help mitigate these effects. USDA's EQIP provides financial and technical help to landowners who voluntarily implement conservation practices. We found that, although EQIP spent almost $5.7 billion dur...

Mining and energy development companies may be required to reclaim lands that they have disturbed—for example, by removing hazardous materials and replanting the land. These companies may also need to provide financial assurances, such as cash or bonds, to cover reclamation costs. We reviewed the financial assurance requirements for surface coal mining, mineral mining, onshore oil and gas extra...

From fiscal years 2011 through 2014, the most recent years for which complete data were available, states awarded at least 3,080 projects under the section 319 program for addressing nonpoint source water pollution, which comes from such sources as runoff from farms, managed forests, and urban areas. Similar to what GAO found in May 2012, the two most common categories of nonpoint source water pol...

As of May 23, 2016, the U.S. Environmental Protection Agency (EPA) had implemented 174 of the 325 recommendations GAO made in fiscal years 2006 through 2015. EPA had not yet implemented the remaining 151 recommendations. The figure below shows the status of the 325 recommendations, which fall into six broad categories that relate to EPA programs and operations. These are: (1) management and operat...

Nearly all of the $1.68 billion of federal funds made available for the Great Lakes Restoration Initiative (GLRI) for fiscal years 2010 through 2014 had been allocated as of January 2015. Of the $1.66 billion allocated, the Environmental Protection Agency (EPA) and the other Task Force agencies expended $1.15 billion for 2,123 projects (see fig.). Agencies can liquidate and adjust obligations for...