Emerging Contaminants and Your Onsite Wastewater Treatment System

When installed, operated, and maintained correctly, septic systems should not pollute groundwater or cause any danger to the drinking water supply. But the unfortunate fact is that pollutants and contaminants do make their way out of septic systems and into groundwater all the same. And this isn’t always to do with poor installation or maintenance — if a septic owner is putting things down their toilets and drains that aren’t meant to be treated by a septic system, these things become all the more likely to get into the groundwater. This is one of the reasons why making sure everyone knows the Three Ps of septic systems is so important! (That’s pee, poop, and toilet paper, of course).

A 2017 study in the journal Environmental Science & Technology showed that American septic systems are regularly depositing pharmaceuticals, consumer product chemicals, and other hazardous chemicals into the environment. Due to their presence in consumer and industrial products throughout society, such chemicals — often called contaminants of emerging concern or emerging contaminants — find their way into bodies and supplies of water in numerous ways, not just through septic systems. They can not only threaten public health by contaminating a human drinking water supply, but cause environmental problems for ecosystems and organisms as well. For instance, the feminization of male fish and fertility issues in other animals have been strongly linked to emerging contaminants.

This 2017 study suggests that besides emphasizing the need to avoid putting pollutants into a septic system, the best way to protect groundwater from septic contamination is keeping septic systems away from the aquifers and wells that supply drinking water. But, of course, many septic systems already exist in such a range and other solutions for preventing them from discharging too many emerging contaminants are needed.

While any chemical going into a septic system that isn’t one of the Three Ps is a contamination risk and absolutely should not enter a septic tank, some chemicals or contaminants will naturally be more of a cause for alarm than others. Right now, the pollutants society is likely most concerned about at large are PFAS compounds and microplastics, both of which have been found coming out of septic systems.

Though PFAS (Per- and polyfluoroalkyl substances, also commonly known as forever chemicals) have become a high-profile concern in more recent years, PFAS have been one of the most frequently detected compounds in drinking water wells since at least 2016, contamination which has been linked to septic systems.  

For more information on protecting groundwater from failing septic systems and forever chemicals, check out this article on the subject from SCS Engineers.

As for microplastics, the impossibly tiny bits of degraded plastic have been found everywhere from clouds to likely into human brains, and some believe septic tanks are the primary source of microplastics found in underwater drinking water reservoirs. The issue of microplastics in its totality certainly cannot primarily be blamed on septic systems, but figuring out how to decrease their presence in as many sources as possible is critical.

Another consideration with microplastics in septic systems isn’t just the environmental contamination — the buildup of solids in the system can also cause issues for the operation of the system. In fact, a 2015 Pumper Magazine article refers to microplastics as “tiny terrorists” in septic systems.

More to the point, microplastics are a type of solid that “remain[s] suspended are small rough to move readily through the screen and into the soil treatment area. If these solids are small pieces of organic material, they will break down or be consumed in the soil. However, if they are inert particles such as … plastics or other synthetic materials, they will not break down in the soil environment and will plug the soil pores, permanently reducing the ability of the soil to accept septic tank effluent. There is no fix when this happens other than replacement.”

Solutions to protect septic systems and the groundwater reservoirs they feed into from microplastics are hard to come by, short of emphasizing to septic owners the necessity of keeping everything but the Three Ps out of their systems and that they should try to buy fewer products containing microplastics to begin with.

Studies Track PFAS Through Wastewater Facilities

This article was featured in a recent edition of Innovations for Small Systems, our monthly water technology newsletter.

University of New Hampshire (UNH) researchers have conducted two of the first studies in New England to show that per- and polyfluoroalkyl substances (PFAS) are ending up in the environment differently after being processed through wastewater treatment facilities, making it more challenging to set acceptable screening levels.

Researchers including Paula Mouser, associate professor of civil and environment engineering at UNH, aimed to highlight the gaps around contaminants of emerging concerns (CECs) in wastewater residuals and to stress that more research is needed to assess the impact of facility design and operation on the treatment of CECs before costly upgrades are implemented to comply with stricter drinking water standards. 

The first study, which was recently published in The Royal Society of Chemistry, investigated the distribution and fate of 24 different PFAS through six New Hampshire wastewater treatment facilities to examine how they are distributed after being treated. The study aimed to characterize PFAS in wastewater treatment influent, sludge, and effluent discharging into the Great Bay Estuary in southeastern New Hampshire. 

The second study, which was featured in the New England Water Environment Association Journal, evaluated the changes in 24 PFAS and 21 pharmaceutical and personal care products (PPCPs) during wastewater treatment and assessed the composition of PFAS in biosolids post-stabilization treatment. Recent studies have suggested PPCPs and PFAS from land-applied biosolids may accumulate in soils, agricultural crops, and food products. This study compares the composition and concentration of PFAS from 39 biosolid samples collected from WWTFs in New Hampshire and Vermont.

Photo Credit: Conservation Law Foundation

The Problem With PFCs

There certainly has been lots of buzz over the scope and extent of perfluorinated chemical (PFCs) contamination of drinking water lately. A Bloomberg Environment analysis of EPA water contaminant data found 65 water utilities in 24 states and territories had at least one sample that came back above the threshold for these chemicals. Altogether, these utilities serve more than six million people. According to one Center for Disease Control official, the presence and concentrations of these chemicals is "one of the most seminal public health challenges for the next decades."

So what do we know about PFCs, then? PFCs are a family of synthetic chemicals used in a wide variety of products such as textiles, packaging, and cleaning products and are also additives in coating/plating processes. One of their most significant uses has been as a compound in firefighting foams used to put out jet fuel fires. In fact, most of the communities dealing with this contamination are ones that rely on groundwater and are located near military installations or airports.

Although scientists are still studying the link between PFCs and certain health issues, some research suggests that exposure to these chemical compounds can cause cancer, and/or liver, thyroid, pancreatic, kidney and fertility problems, among other things. Moreover, PFCs are stable in the environment and resist degradation, allowing them to seep out of underground storage tanks and build up in the bodies of animals and humans.

While the U.S. EPA has issued health advisories of 70 parts per trillion (ppt) for PFCs in drinking water, it is still evaluating health effects before taking any further action. These advisories are designed to provide drinking water system operators, and state, tribal and local officials who have the primary responsibility for overseeing water systems, with information on the health risks of these chemicals, so they can take the appropriate actions to protect people. But just exactly who will pay for these actions, or how the money will be located in the first place, is undetermined. The Seattle suburb of Issaquah, WA, for example, has already paid $1 million to install filters on its wells, and unless income can be generated from legal claims, this will certainly affect their customers' water bills.

Earlier this year, U.S. Senator Shaheen (D-NH) introduced the Safe Drinking Water Assistance Act, bipartisan legislation that will help expedite the analysis of PFCs, and provide resources to states dealing with the health challenges posed by these potentially harmful substances. And last week, the President signed H.R. 2810 which includes an amendment for a nationwide health study to be conducted by the CDC on the implications for PFCs in drinking water. In addition, some states, such as Michigan, are creating multi-agency response efforts to address this rapidly evolving public health issue.

If you need more information about PFCs, a good place to start is this EPA website or video. In addition, EPA has published a new fact sheet entitled “Protecting Public Health & Addressing PFAS Chemicals,” to provide basic information to the general public. And the AWWA has its own fact sheet on the prevalence and assessment of perfluorinated compounds in drinking water, as well as this listing of resources for identifying and managing PFCs.

Top 2017 Resources from WaterOperator.org's Bi-Weekly Newsletter

2017 was a great year for the WaterOperator.org newsletter team. We not only reached our 200th edition milestone this past fall, but we also were successful in connecting a significant number of water professionals with useful and relevant resources, resources that could be used on-the-spot to solve pressing issues, or help guide utility best practices, or help water decision-makers plan ahead for their communities. 

While many of the events, articles and resources featured in our newsletters garnered interest, here is a list of our most clicked-on resources of 2017.

• A Water Security Handbook: Planning for and Responding to Drinking Water Contamination Threats and Incidents, US EPA This document provides guidelines for utilities to plan for possible contamination incidents, including sampling, public health procedures, and recovery.
• At the Confluence of Nutrients, Pharmaceuticals and Sustainability: Emerging Issues in Wastewater Management, University of Michigan/Central States Water Environment Association  This presentation discusses the effects of emerging contaminants on wastewater treatment and possible solutions.
• Sampling Guidance for Unknown Contaminants in Drinking Water, US EPA This document provides new guidance to first responders and drinking water utility operators on the collection, storage, and testing of potentially contaminated drinking water when the contaminant is unknown.
• Water Conservation Techniques For Small and Medium Water Systems, Florida Rural Water Association This paper provides thorough descriptions of water conservation measures that have been demonstrated to be effective for small water systems.
  
• The State of Public Water in the United States, Food & Water Watch A compilation of water rates of the 500 largest community water systems in the country (the largest water rate survey of its kind in the country). 
• Emergency Disinfection of Small Water Systems, Washington State Department of Health  Emergency, stop-gap measures to get water quickly to the public in a crisis situation. 

Did you use one these resources at your utility this year? If so, we'd love to hear from you! Do you have a favorite "go-to" resource to share? Again, we'd love to know! Our email is info@wateropertor.org , or connect with us on Facebook or Twitter.