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Surface Water: What You Need To Know

Surface Water: What You Need To Know

Map of surface water withdrawals in the USA

Analies Dyjak | Policy Nerd

Surface water is an extremely important natural resource. From the water we drink, give to our pets, and use for recreation, we are dependent on its various uses. Surface water is continuously being threatened by anthropogenic activities. It’s extremely difficult and costly for municipal treatment facilities to keep up with new contaminants that are polluting waterways every single day. Additionally, federal regulations don’t reflect the large scope of surface water pollution. This blog post discusses the various threats to surface water and why humans should care.

What Is Surface Water?

Lakes, oceans, streams, rivers, ponds, reservoirs, and wetlands are the various types of surface water. Freshwater sources are responsible for providing potable drinking water to 84% of the nations population. Surface water is different from groundwater because it has the ability to disperse and become diluted as it travels throughout a body of water. Groundwater aquifers are essentially holding tanks for highly concentrated contamination. There’s less room for contaminants to move around, and less volume for the contamination to become less concentrated.

How Does Surface Water Become Polluted?

Surface water is extremely susceptible to pollution because it occupies such a large portion of the earth’s surface. Surface water pollution is almost entirely the result of human activities. Agriculture, mining, factory effluent, landfills, human/animal waste and localized pollution are just some of the most common sources of surface water pollution. Topography and geological formations create natural surface water runoff, but human manipulation of the land increases flow rates and overall contamination.

Point source pollution comes from an easily identifiable source, like a factory or sewage treatment plant. Point source pollution is discharged through a pipeline, ditch, or any “discrete conveyance” that directly or indirectly enters a body of water. Point sources are typically regulated by National Pollutant Discharge Elimination System (NPDES) permits.
Non-point source pollution is much harder to regulate because the source is not easily identifiable. Agricultural and stormwater runoff are the two most common types of nonpoint source pollution. Heavy rain events cause contaminants to runoff from roads and fields, collecting debris and pollution as it travels into a body of water.

How Do You Mitigate Surface Water Pollution?

It’s expensive and nearly impossible to mitigate a contaminant once it has entered surface water. For some contaminants, the solution is typically self-mitigating. A contaminant will become diluted to extremely small concentrations after it has traveled and dispersed throughout a body of water. Additionally, some contaminants are still extremely toxic at very small concentrations. There are also several persistent contaminants that never fully decompose in nature (PCBs, DDT and Dioxin), or take hundreds of years to degrade. As we’ve seen in Wilmington, North Carolina, and Maplewood, Minnesota, municipal water treatment facilities are only equipped to remove certain types and quantities of surface water contamination.

What Is Currently The Biggest Threat To Surface Water?

Man-made compounds are one of the largest threats to drinking water sources. Per and Polyfluoroalkyl Substances (PFAS) are a category of man-made “emerging contaminants,” which means they have been detected in the environment but the risk to human health is not well-understood. Chemicals such as GenX, PFOA, and PFOS are all common contaminants that fall under the category of PFAS. DuPont, Chemours, and 3M have been using variations of these chemicals in industrial and consumer products since the early 1950’s. Scotchgard, Teflon, firefighting foam, metal plating, heat/water repellent chemicals, and stain resistant fabrics are common uses of PFAS. They are extremely persistent in the environment, which means they do not readily degrade. PFAS effluent is either directly dumped from a factory into surface water or a dug ditch, which will then percolate into groundwater. This is allowed because PFAS are unregulated by the federal government.

North Carolina’s Cape Fear River has been unknowingly experiencing surface water contamination for years. A Chemours plant located in Fayetteville, North Carolina, had been discharging various types of PFAS into the Cape Fear River since the 1980's. The Cape Fear is the primary drinking water source for residents of Brunswick and New Hanover County. Their water resource is now tainted with a dangerous contaminant that's unregulated by the federal government.

Algal Blooms and Surface Water

Algal blooms are another major threat to surface water. An influx of nutrients or heat can increase the quantity of algae. Often, this overload of nutrients is the result of agricultural fertilizer runoff. Harmful Algal Blooms or HABs occur after an influx of nutrients or a sudden increase in water temperature. HABs can then produce cyanotoxins, which are harmful to humans and the environment.

How Can I Protect Surface Water?

Protecting surface water from contamination will not only improve drinking water quality, but also valuable habitats. Here are some tips for local level surface water management:

Watershed Management: Municipalities should look at watersheds as an entire system, rather than exclusively a water resource. Watershed management surveys the land surrounding a body of water to determine the natural flows and influxes.
Eliminating Pesticides, Herbicides, and Fertilizers: What’s bad for plants and animals is also bad for humans. This category of surface water pollution runs off directly into surrounding bodies of water and affects fragile surface water ecosystems. Reducing or eliminating the use of pesticides, herbicides, and fertilizers will reduce the amount of necessary additives by municipal water treatment facilities to eliminate contaminants.
Reduce Impervious Surfaces: Impervious surface is any type of ground cover that prevents water from infiltrating into the ground. Pavement or asphalt is the best example. Impervious surface increases runoff flow rates into surface water, and prevents groundwater from naturally filtering contaminants. Next time you’re thinking about paving your driveway, consider a pervious alternative such as porous asphalt or pervious concrete.
Hold Municipalities Accountable: Stay current with commercial and industrial development within your community. Public comment periods are required prior to development and prior to obtaining a NPDES permit. Companies are required to address each question and concern individually, so if development plans raise personal concern, don’t be afraid to utilize the public comment period.