Conservation of Water Quality and Watershed Health: Drinking Water

by Carol Armstrong

This overview focuses on risks and impacts to human uses of water, and only marginally addresses problems for aquatic species, biodiversity, and ecological systems. It does not address all the components of concern in our water. By knowing some of the benefits and limitations to our water treatment, it is hoped that residents will be more aware and thoughtful of their handling of everyday pollution. Community organizations such as environmental advisory councils might take on the challenge of educating their towns so that when the expensive business of updating water treatment plants (WTP) arises, residents and businesses will understand our roles in keeping polluted water out of the sewer system. This report first reviews the types of threats to water quality in the U. S., and then provides information about the capacities of water treatment plants. The EPA requires drinking water treatment plants to test for almost 90 different contaminants. Drinking water supplies in the U.S. are among the safest in the world, however, best practices protect streams from contaminants. We end by considering what we can each do individually to protect clean drinking water.

A. Types of threats to water quality:

• Suburban/Urban Runoff Pollution and Sediments from Impervious Surfaces: Stormwater does filter into the ground as in the forest, but discharges at high velocity into streams due to buildings and roofs, highways and roads, driveways, parking lots, lawns, sidewalks, construction sites, ball fields, other developed grass fields such as parks, and paved trails. Stormwater discharges directly into streams, lakes, reservoirs, estuaries, bays, and oceans;
• Agricultural Pollution: Farm fields can produce as much runoff as urban streets. Tilling the soil and leaving fields bare off season produce more runoff than a growing field. Excessive levels of nitrogen and phosphorous cause eutrophication (too many nutrients), which indirectly cause oxygen deprivation in the stream and impair aquatic habitats. Farming practices that permit farm animals to access streams, grow crops up to the stream bank, or otherwise do not protect streams through tree plantings with a minimum 35’ riparian buffer, usually do not have diverse macroinvertebrates in the stream, which are the best indicator of stream health. Agricultural pollution also contributes to excessive levels of herbicides and pesticides, ammonia, and nitrous oxide, as well as excessive levels of sediment that smothers aquatic life that live on the stream and estuary/bay bed, for example, as reported by the Chesapeake Bay Commission. 
• Industrial Pollution: Industrial facilities in the past were permitted to release pollutants into natural waterways, leaving legacy toxins in the soil and water. In Pennsylvania we also have many thousands of landfills, Superfund sites, State hazardous waste sites, and abandoned coal mines that leak and runoff to streams and other waterways;
• Fossil Fuel Extraction and Transportation including coal, other mineral mines, oil, and gas reach our surface and ground water supplies. Extraction and mining infrastructure operation and accidents also take clean water from the environment and release water with industrial chemicals used for extraction into our freshwater supplies when discharging into groundwater or on the surface;
• Air Pollution – contaminants and particulates from ambient air – is a significant source of water pollution, such as acid rain, and comes from airborne emissions and atmospheric dust and greenhouse gases that are absorbed into water. The Pennsylvania Department of Environmental Protection (PADEP) has investigated the impacts from air emissions from unconventional gas production within Washington County, and monitors sites in eastern and western PA (https://www.dep.pa.gov/Business/Air/BAQ/MonitoringTopics/ToxicPollutants/Pages/Toxic-Monitoring-Sites-in-Pennsylvania.aspx#.ViaHEE3D-Uk)
• Sewage Treatment Plants contribute to water pollution because even the most updated plants cannot fully filter out the various pollutants and chemicals. Cities with combined sewer overflows (CSO, associated with older cities) are permitted by law to discharge untreated and raw sewage directly into a stream, river, or body of water during precipitation events that overwhelm a treatment facility. A CSO is designed to collect and combine stormwater runoff, domestic sewage, and industrial wastewater in the same pipe. Most of the time, CSOs transport all of their wastewater to a sewage treatment plant where it is treated and then discharged to a water body except when the volume of wastewater exceeds the capacity of the treatment plant or sewer system and untreated stormwater and wastewater discharges directly to nearby streams. The Philadelphia Water Department reports there are 164 CSOs in Philadelphia that discharge to Cobbs, Tacony, and tidal Pennypack Creeks, and Schuylkill and Delaware Rivers. Street inlets, building downspouts, and storm sewer lines discharge into nearby streams in every watershed in Philadelphia. Pennsylvania is a state with one of the greatest number of cities with CSO outfalls directly to streams and rivers. The EPA reports there are 860 municipalities with CSOs in the U.S. As a world leader in water quality, Philadelphia’s strategy is to reduce 85% of their CSOs by building thousands of green infrastructure sites. Other towns can model this locally, as it is less expensive in the short term and in the long term, than replacing or upgrading sewer treatment plants.

B. Public Water Treatment Plants CAN Remove:

• Dirt and other dissolved particles by adding chemicals (chlorine, iodine, oxidizing agents) that bind with the particles and form larger particles, called floc, that are filtered with screens, grit chambers, sedimentation tanks, and then pumped out and used on soil, landfill, or incinerated thus releasing toxins in the solids.
• Parasites, bacteria, and viruses are removed by filters.
• Chlorine or chloramine (compound of chlorine and ammonia, weaker disinfectant than chlorine, stays in water much longer) may be added to kill remaining pathogens. Filtration techniques can be purchased by residents to filter chlorine and chloramine (separately). Chloramine filtration at this time requires a whole house filtration system.
• Suspended solids such as algae and fungi are removed.
• Minerals such as iron and manganese are filtered.
• Much of phosphorus, in the form of phosphates (from soils/rocks, human and other animal waste, detergents, food residues) are dissolved and removed by water treatment plants with that capacity (usually not food and beverage industry wastewater treatment systems).
• Some nitrogen may be removed by water treatment systems, and the EPA limit for drinking water is 10 ppm. Nitrates are increasingly understood to cause significant health risks including “blue baby syndrome”, colon and rectal cancers, and the most common condition - methemoglobinemia. The United National Environmental Programme and the Global Environment Facility concluded in 2018 that it was important to reduce by half the amount of nitrogen that humans deposit into the environment by mid-21st century.
• Concentrations of pharmaceuticals in rivers and lakes are increasing worldwide. The causes of pharmaceuticals in drinking water supplies are treated effluents from wastewater treatment plants, and leaching of pharmaceuticals to groundwater from sources such as leaking sewage systems and pipes. The rates for removal of pharmaceuticals from drinking water treatment plants vary by the techniques used by the plant. Wastewater effluent is where much of the pharmaceuticals and hormones are found, and these treatment plants remove about half of our medications. Due to the increasing demand for water, wastewater reclamation plants are operating to produce water that, among other uses, is reintroduced into groundwater and used for drinking water supplies. Little is known if wastewater reclamation plants remove pharmaceuticals and hormones, or how effectively they do so, however recent studies suggest effluents are inadequately treated. Unused drug collections sites exist today for preferred disposal.

C. Water Treatment Plants DO NOT Remove:

• Salts are not currently removed, though chlorides in drinking water in the northern U.S. are increasing and some day may reach the maximum for drinkable water;
• The EPA reported in 2016 that personal care products are increasingly being detected at low levels in surface water, may impact aquatic life, and are being consumed by humans in combinations that we cannot predict;
• Many “contaminants of emerging concern”, that are commonly derived from municipal, agricultural, and industrial pathways, are endocrine disruptors that alter the normal functions of hormones causing a variety of health effects, including “plastispheres”;
• Arsenic is used in pesticides and agriculture; organophosphate pesticides are being phased out and replaced with glyphosate, pyrethrinoids, and neonicotinoids, which are less harmful but which are unhealthy for plants and animals;
• Home filters are needed to remove lead, chlorine, and other contaminants;
• PCBs (and other polychlorinated compounds) were in strong industrial use until 1977. They persist in the environment, are toxic, and they bioamplify along food webs as far as the earth’s poles;
• Polybrominated compounds are used as flame retardants that replaced polychlorinated compounds. They have also appeared in the Arctic and Antarctic environments and some are now being regulated;
• Neonicotinoids are persistent in the environment and target ‘pests’ as well as pollinators, particularly honey bees;
• Plasticizers are added to synthetic resins to increase the flexibility of plastics, and are endocrine disruptors that are not filtered out by sewage treatment plants;
• Perfluorinated chemicals. PFAs (perfluoroalkyls and polyfluoroalkyls) are fume suppressants and aqueous film forming foams used in making many products, which persist in the environment, bioaccumulate, and cause immunotoxic and hepatotoxic toxicity. The EPA published health advisories for PFOA (perfluorooctanoic acid, used worldwide as an industrial surfactant and fed to meat animals) and PFOS (perfluorooctanesulfonic acid, was a key ingredient in Scotchgard and in stain repellents). They are extremely persistent in the environment. Several states including Pennsylvania are investigating and developing systems for the identification of risk in residents, treatments, and prevention of PFOA and PFOS from reaching drinking water.

D. What Can We Do?

As always, prevention is much less expensive than cure or treatment after damage has occurred. Industry is seeking methods to derive energy, chemicals for commercial markets (such as phosphorus, iron, calcium, aluminum salts), and clean water from sewage. Sewage sludge has long been proposed for incineration and use, but it retains many harmful metals and chemicals (e.g. dioxin), and is a health risk. A current trend is the recycling of water from industrial for reuse (e.g., beer brewing and in-door farming), rather than drawing more fresh water. Some mushroom producers are recycling their water on site so that it is reused, rather than spraying wastewater onto fields. Increasing regulation and updated water treatment systems will come with increases in taxes, savings in water treatment, and/or new funding sources in order to try to keep up with the treatment of chemicals accumulating in our soil, water, food sources, and our bodies.

What can you do as an individual? Take time to think about your purchases, and try to refuse, reduce, and find nontoxic and simple alternatives for using plastics, processed food, medications, beauty and personal care products, cleaning products, clothing made from synthetic materials, lawn products, pesticides, conventionally farmed food, and meat/fish.

Join and volunteer with a watershed association, a Chesapeake or Delaware Bay association, environmental research center, other environmental conservation organization, or public park or forest to learn about alternatives to chemicals and how to prevent biological pollution of our natural spaces. It will require major changes in thinking, many of which are not difficult once the mental shift has occurred, such as not using pesticides or herbicides on lawns, switching lawns to pollinator meadows that reduce stormwater runoff, and only using reusable items for food and shopping. Learn about and support our State and National Parks, Wildlife Refuges, and National Marine Sanctuaries. Take a training course as a Master Watershed Stewardship, Master Gardener, or Master Naturalist which will given you the opportunity to network and join with the amazing environmental protectionists of Pennsylvania and our partners. If you want to defend the Earth – dig in, and support!

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