To Report on Drinking Water, Know Its Source

July 11, 2017

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Backgrounder: To Report on Drinking Water, Know Its Source

By Joseph A. Davis

Water drinkers are not a special-interest group. Everyone consumes the stuff. So why is it so hard to make it safe to drink? 

The challenge of providing drinkable water is not new. Neither is it one that has been solved in many places across the United States. 

The Flint debacle — where people’s taps spewed undrinkable water — got media attention in 2015. Only later did news organizations like USA TODAY and CNN show that the problem of lead in water was widespread across the United States.

Water from a faucet
The Safe Drinking Water Act, passed in 1974, tries to address the issue of contaminants. Photo: U.S. Environmental Protection Agency

Environmental journalists everywhere work for audiences who care about this — or should. Telling the story requires understanding of a complicated partnership involving federal, state and local governments, as well as water utilities and private citizens.

The U.S. Environmental Protection Agency has played a key role since the 1970s, but your story may depend even more on your local agencies.

It also requires understanding of where water comes from and what treatment can and can’t do. Virtually everyone in the United States gets their drinking water from either a public water system or a private well. But whether the water is pure enough to drink depends on where it comes from.

Source water assessments a starting point for reporters

There are many substances that can contaminate drinking water, and can harm people’s health even in small amounts. The list of regulated microbial, chemical and even radiological contaminants is large, although some say it needs to be larger.

In some cases, the contaminants come from source water, and treatment plants are hard-pressed to remove them. Small amounts of contamination matter, because when people drink the water every day, the health effects can build up over years.

The Safe Drinking Water Act, or SDWA, first passed in 1974, tries to address the issue of contaminants — a key part of the law focuses on “source water protection.”

The 1996 amendments to SDWA (42 USC 300j–13) encouraged public drinking water systems above a certain size to conduct “source water assessments.” If state or local agencies do conduct source water assessments, SDWA requires them to be made public. 

For reporters, these are an important starting point. No list of source water assessments exists, but they are managed by state drinking water agencies, which are listed here. They are also required to be accessible through the annual “Consumer Confidence Reports,” or CCRs, which public drinking water systems must publish. Find your local CCR here.

Private wells or public drinking water systems?

Around 15 million U.S. households get their drinking water from private wells. These are not regulated by EPA or SDWA, and state requirements may be minimal.

Private wells may be vulnerable to contamination from failed septic tanks, poorly managed landfills, underground fuel storage tanks, fertilizers and pesticides, and urban runoff.

Such situations can cause real problems and generate important news coverage, as the contamination in Kewaunee County, Wisc., has shown. Private wells are often poorly monitored, so problems may remain undiscovered for a long time.


It is important to understand what 

treatment of drinking water in

public systems can and cannot do.


On the other hand, public water systems get their supply either from lakes and streams (about 66 percent of the total on a national average) or from groundwater aquifers.

Surface water, the water in lakes and streams, is supposed to be protected from most pollution under the Clean Water Act. How well the CWA protects people (or should protect them) is a matter of ongoing national and local controversy.

Enforcement of the Clean Water Act is to some degree left in the hands of the states. The pollution that slips through can and does affect drinking water.

When thinking about source water protection, it is important to understand what treatment of drinking water in public systems can and cannot do. Advanced treatment costs more, and cost is a constraint for many small systems. Screening and settling basins can remove most solids. Flocculation can remove most of the smaller particles which remain in suspension.

Further filtration is a key step that often varies according the the size and budget of the system. Physical filtration through media like sand can remove smaller particles including many microorganisms. Filtration through special media like carbon can remove some dissolved contaminants, including toxic chemicals.

More advanced technologies, such as reverse osmosis, can remove even more pollutants, but are too expensive for ordinary use. Disinfection, most often by adding chlorine compounds or chlorine, kills most of the microorganisms in the water. But some contaminants may still get through, and that is why source water matters.

Considerations for coverage

Sewage Treatment Plants. When sewage treatment plants work right, under the terms of the CWA, they prevent pollution of water bodies that are sources of drinking water. But they don’t always work right. Upsets of the microorganisms they depend on to digest sewage, or high water flows during storm events, may cause them to pollute. This may bring water contaminated with pathogens to the intakes of drinking water plants, which then become the last line of defense. Some emerging pollutants, like pharmaceuticals, may not be removed by conventional sewage treatment.

Industrial Discharges. The CWA is supposed to regulate industrial wastewater discharges into surface waters through a system of permits, mostly administered by the states. But for a host of reasons, some pollutants get through — and industrial pollutants are often more toxic than others. Sometimes the industrial pollutants in water bodies were put there decades ago, before the CWA was even in effect. The worst of these cases may be on the Superfund National Priorities List.

Septic Systems. People in remote or rural areas who are not connected to municipal sewer systems usually use septic tanks to manage their household wastewater. When located, operated and maintained properly, septic systems can prevent pollution. Otherwise not — and pollution from failing septic systems can pollute both private wells and public drinking water sources. The worst threat to drinking water may be pathogens.

Agricultural Runoff. When rain falls or snow melts, water can run off of farm fields. The runoff may include fertilizer and pesticides that have been applied to the fields. Fertilizer components such as nitrogen and phosphorus can cause algal blooms in downstream waters. Among the pollution problems those algal blooms cause may be toxins such as microcystin that cannot be removed easily by drinking water plants. This is what happened in Toledo in 2014. Improperly managed fertilizers can also cause higher levels of nitrates in source water, which can harm people’s health and are hard for drinking water plants to remove.

Feedlots and Manure. Today’s agricultural landscape includes many kinds of animal operations, and these inevitably produce manure and other biological wastes that may include pathogens as well as nutrients. Manure is not always managed well, and may cause pollution. When liquid manure is held in unlined ponds, it may contaminate groundwater. When heavy storms overcome containment structures, it may contaminate surface waters.

Watersheds and Reservoirs. The lakes and streams that serve as drinking water sources collect precipitation from much wider basins we call watersheds. The governments that provide drinking water often take extra measures to protect these catchment areas from pollution. An example is the effort to maintain forest land cover in much of the area that supplies New York City. Watersheds typically contain a variety of pollution sources (everything from dog poop to construction sediment), so comprehensive plans are needed.

EPA operates a “Healthy Watersheds Protection” program that tries to build partnerships among federal, state and local agencies. For example, it works with the Agriculture Department’s Natural Resources Conservation Service, which works on farmland soil conservation. But federal funding is limited, and what there is must be highly leveraged. More location-specific info is here.

EPA maintains a nifty and useful Surf Your Watershed database — online, interactive and mapped — which can help you get started in investigating the issues in your area. EPA’s website also offers a cool interactive widget called Drinking Water Mapping Application to Protect Source Waters (DWMAPS), which can help you analyze source water issues.

Injection control and other groundwater protection mechanisms

SDWA allows EPA to designate “sole source aquifers,” when an aquifer supplies at least 50 percent of the drinking water for an area and there is no reasonable alternative should it become contaminated. The aquifers underlying Long Island are a good example.

When an aquifer is designated sole source, federal projects must be reviewed to prevent any negative impact. An interactive map of designated sole source aquifers is here.


Done right, underground injection may

not harm drinking water aquifers.


Another SDWA provision that may protect drinking water sources is the underground injection control program. This little-known initiative is important because of the rise of “fracking” in oil and gas operations over the past decade.

A variety of industries inject toxic and hazardous waste fluids via wells into deep geological formations, under the presumption that they will be permanently isolated there. Because this may not always be the case, SDWA sets up a regulatory program, overseen by EPA, which gives much authority to the states. It is a complex subject beyond the reach of this backgrounder, but you can find more about it here and here.

Done right, underground injection may not harm drinking water aquifers. Waste-receiving formations are supposed to be deeper than drinking water aquifers, which are typically shallow, and are isolated from them by impermeable geological layers. When well casings are done with integrity (e.g., sound pipe and proper cementing), leaks into aquifers may be prevented. But not always.

Fluids are injected under high pressure, which amplifies any leakage problems. When receiving formations are right below aquifers used for drinking supply, any problems may be serious — even if only for private well-owners.

Problems may be made worse by lax federal and state enforcement. And the law itself has loopholes, which often benefit the oil and gas industry. The so-called “Halliburton loophole” passed by Congress in 2005 prevents the public from knowing what toxic chemicals fracking operations are injecting underground.

Other information sources

Some groups with useful perspectives and information about source water protection for drinking water include the Center for Watershed Protection, the National Rural Water Association, the American Water Works Association, the Association of State Drinking Water Administrators, the Association of Clean Water Administrators and the Association of Metropolitan Water Agencies

Joseph A. Davis is director of SEJ’s WatchDog Project, and writes SEJournal Online’s Backgrounders and TipSheet columns.

* From the weekly news magazine SEJournal Online, Vol. 2, No. 27. Content from each new issue of SEJournal Online is available to the public via the SEJournal Online main pageSubscribe to the e-newsletter here.  And see past issues of the SEJournal archived here.

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