Water Quality & Public Health

Do you think about the hydrologic cycle in your watershed when you turn on the tap or dangle your toe in a stream?  If not, you should. Every upstream use of that water could affect your health.

Pollutants found in our finite stash of fresh water around the globe come from a variety of sources, from sewage to industry to household chemicals. Under the Clean Water Act, the U.S. Environmental Protection Agency (EPA) regulates pollutants in streams and other waterbodies by setting ‘pollutant diets’ called Total Maximum Daily Loads (TMDLs) based on the monitoring of impaired waters.  While some of the categories of regulated pollutants impact non-human species more directly (e.g., nutrients such as nitrogen and phosphorus may lead to streams unsuitable for fish,), the regulated categories of pollutants which relate most directly to our own health include pathogens, metals, and chemicals.

The most immediate tie between water quality and public health is bacteria in waterbodies. In a recent story on NPR, Carol Nemeroff, a contagion psychologist from University of Southern Maine, pointed out that, “ . . . there is no water that has not been pooped in somewhere” (Spiegel 2011).  Fecal coliform bacteria is a standard measure of water quality but is actually only an indicator of some source of feces, and therefore potential for a variety of pathogens in the water.  Sources for bacteria are typically categorized as human, domestic animal, agriculture, or wildlife. Human sources of fecal coliform bacteria are often a sign of improperly treated wastewater, leaking sewer infrastructure, or the result of combined sanitary and storm sewer overflows (CSOs).  Contagions are a major concern in waterbodies that are used for recreation where the bacteria count is high.

Toxics including various chemicals, mercury and other heavy metals found in waterbodies are another tie between water quality and public health.  The EPA Toxics Release Inventory (TRI) database reports the release of toxic industrial and commercial chemicals.  The TRI includes over 600 different toxic chemicals from thousands of facilities in the U.S.  Household chemicals such as pesticides may also contribute to toxics in watersheds.  These chemicals and metals often settle in sediment at the bottom of streams and other waterbodies or can collect in fish tissue. EPA TMDLs list impairments by watershed and waterbody  on their website. For example, some waterbodies in Baltimore County, Maryland have TMDL regulations for mercury, chlordane, and PCBs. These toxic sediments can become a public health issue if citizens come in contact with the bottom soils in streams and waterbodies or if they consume fish from these waterbodies. Check the EPA web site for more information on fish consumption advisories.

Perhaps the least understood pollutants found in water are the result of pharmaceuticals that are often not filtered through conventional wastewater treatment. These include pain killers, birth control hormones, and antibiotics, which are not only flushed down toilets as pills, but are also in human and animal waste.

While we may understand the effect of these drugs on our bodies in the short term, we definitely do not understand the impact they could have on our aquatic ecosystems and long-term consumption as part of our water supply if they are not broken down through treatment processes.  Recent studies have already shown impacts to wildlife, such as male fish showing female characteristics.

The good news is that we can filter many pollutants out of water using ecological processes such as stream restoration, stormwater management, and constructed wetlands for wastewater treatment. By aerating water we can remove a high percentage of bacteria and pathogens from the water. Some plant species will uptake heavy metals into their leaves which can be burned and reclaimed from the soil.

What can you do? Supporting regulations for industrial and commercial pollutants may prevent further toxics from entering our waterways. Being conscious of your use of household chemicals, fertilizers, and the disposal of pet waste can also play a role. Becoming active in your local watershed or Waterkeeper organization can be a great way to learn more about your local waterways. Participating in local volunteer activities to monitor and clean your streams, rivers and other waterways can be a fun way to connect with these organizations and contribute to ongoing efforts to improve watershed and public health.

Of course, the best way to deal with pollutants in water is to prevent them entering the watershed in the first place. Biohabitats is honored to be involved with one community that is making progress in that regard. After signing a joint agreement to protect and improve their shared watersheds, Baltimore City and Baltimore County, Maryland put together a plan of action toward that goal. As part of this plan, the City and County will convene a roundtable discussion involving public health and water quality experts next month to discuss what research has been done, what still needs to be done, and how best to remedy the issue of bacteria in Baltimore’s watersheds.