Guest Column | December 21, 2015

Assessing PPCPs: How To Handle The Micropollutants That Pose A Major Threat

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By Melanie Redding, L.HG, hydrogeologist and Brandi Lubliner, PE, environmental engineer, Washington State Department of Ecology

A study conducted by the state of Washington’s Department of Ecology and the EPA assessed the efficacy of PPCP treatment removal rates of various wastewater treatment processes.

Pharmaceuticals and personal care products (PPCPs) are widely present in the environment. PPCPs are anthropogenic contaminants; their presence in the environment results from the universal, frequent, and cumulative usage by multitudes of individuals. Large quantities of pharmaceuticals are used to treat and cure diseases and other medical conditions. PPCPs enter the environment primarily as they pass through the body or are improperly disposed of in toilets, sinks, and the trash.

PPCPs include drugs made for humans and animals — prescription and over-the-counter drugs. This definition includes drugs used for human, veterinary, livestock, and aquaculture. It includes diagnostic agents, nutraceuticals, and excipients.

Conventional wastewater treatment plants were not designed to treat for PPCPs, and it is widely believed that the PPCP compounds migrate into groundwater and surface waters from treated and untreated wastewaters.

Personal care products are items that individuals use every day to take care of themselves. They include a wide variety of products — shampoo, deodorant, toothpaste, lotions, makeup, after-shave lotions, hair dyes, anti-dandruff shampoos, teeth whiteners, sunless tanning products, colognes, and fragrances. There are more than 10,500 chemicals used in personal care products. Only 11 percent of these chemicals have been tested for safety in the U.S.

Low concentrations of PPCPs have been detected in surface water, groundwater, marine waters, soils, sediments, and drinking water. Conventional wastewater treatment plants were not designed to treat for PPCPs, and it is widely believed that the PPCP compounds migrate into groundwater and surface waters from treated and untreated wastewaters. There is concern about the effects on wildlife and human health from these chemicals at low concentrations in the environment. It is unclear how the unintended exposure to low concentrations of multiple chemicals may affect an organism or an individual.

Tracking The Problem
PPCPs enter the environment from several different sources. Human sources are the predominant ones, releasing PPCPs after they have been used, either as they are washed off the body or excreted. Additionally, PPCPs are often disposed down the drain or in the trash, and these enter the environment either through wastewater treatment systems or landfills. Other sources include livestock, agriculture, pets, and aquaculture.

Humans typically excrete 50 to 90 percent of the active ingredients in ingested drugs, either as unmetabolized pharmaceuticals or as metabolites. When these excreted chemicals leave the body, they typically enter a municipal wastewater treatment facility, an on-site sewage system, or a reclaimed water treatment facility. Treatment processes vary in their treatment efficiency for PPCPs. Typically, wastewater from the treatment system is discharged into the environment.

Washington Department of Ecology’s Brandi Lubliner collects a sample at a wastewater treatment plant.

Consumers dispose of an estimated 25 to 33 percent of pharmaceuticals sold, either to a landfill or wastewater treatment plant. Ultimately, these disposed PPCPs enter a municipal wastewater treatment facility, an on-site sewage system, or a reclaimed water treatment facility. Unused or expired PPCPs thrown away in the trashcan and disposed in a landfill can be mobilized in the environment via landfill leachate.

The fate of PPCPs in the environment is complex for a number of reasons. First, there are thousands of chemicals used in the manufacture of a wide variety of PPCPs. Not all PPCPs are similar chemically, and the different types of chemicals react differently to different treatment processes. The individual chemical structure dictates whether PPCPs will biodegrade, volatilize, degrade into metabolites, or concentrate and persist in the environment.

The results of this study indicate that PPCPs are routinely found in municipal wastewater, PPCP removal varies between wastewater treatment processes and specific chemicals, and advanced nutrient reduction and tertiary filtration may provide additional PPCP removal.

Treating The Problem
The treatability of PPCPs depends upon the physicochemical properties of each compound of interest and the specific set of treatment processes. Some treatment processes efficiently remove some chemicals but are ineffective at treating others. Some treatment processes merely remove the chemical from one media and transfer it to another media without destroying it. For example, nonylphenol is removed from water through settling, but in the process it is partitioned into the sludge. Once land-applied, it remains in the environment, available for transport to groundwater or surface waters. Typical treatment processes include adsorption, filtration, volatilization, photodegradation, biodegradation, chemical alteration, and plant or animal utilization.

In summary, no single treatment process effectively removes 100 percent of PPCPs. Some treatment processes reduce some pharmaceuticals to very low levels, while other pharmaceuticals remain resilient.

In 2008, the Washington Department of Ecology and the U.S. EPA conducted a study to characterize PPCPs at five municipal wastewater treatment plants in the Pacific Northwest. The goal was to characterize wastewater treatment removal efficiencies for these compounds by monitoring a range of treatment processes and their effect on PPCP removal. This study compared untreated wastewater (influent), treated wastewater from secondary treatment, advanced tertiary treatment for nitrogen and phosphorus (nutrient) removal, tertiary treated reclaimed water, and biosolids.

Target analytes included 172 organic compounds, PPCPs, hormones, steroids, and semi-volatile organics. Removal efficiencies were evaluated for each analyte at the five wastewater treatment plants.

The study found PPCPs in all samples, and their concentrations were comparable to those reported in the literature from other studies. Overall, conventional secondary treatment reduced 21 percent of the 172 organic compounds to below detection levels and achieved high removals for hormones and steroids. Advanced nutrient removal and filtration technologies reduced the number of compounds detected by 53 percent. A total of 20 percent of the 172 compounds were found only in the biosolids, suggesting that some PPCPs can concentrate in solids.

None of the wastewater treatment technologies was able to remove all of the compounds. These resilient compounds include carbamazepine, fluoxetine, and thiabendazole. These three PPCPs may serve well as human-influence tracer compounds in the environment.

The results of this study indicate that PPCPs are routinely found in municipal wastewater, PPCP removal varies between wastewater treatment processes and specific chemicals, and advanced nutrient reduction and tertiary filtration may provide additional PPCP removal.

Based on these findings, researchers recommend that consumers do not flush leftover, unwanted, or expired drugs. Instead, they should be taken to a pharmacy which has a takeback program. It’s best to contact the local health department, law enforcement office, or pharmacy for information on local medicine take-back programs and initiatives to support pharmaceutical stewardship in a given area. If a take-back program is not available, medicines should be taken out of their original containers, mixed with an undesirable substance (such as kitty litter or coffee grounds) and placed in an impermeable container, then put in the trash.

Go to https://fortress.wa.gov/ecy/publications/documents/1003004.pdf to read the full study conducted by the state of Washington’s Department of Ecology.

Cited Work
Lubliner, B., M. Redding, and D. Ragsdale, 2010. Pharmaceuticals and Personal Care Products in Municipal Wastewater and Their Removal by Nutrient Treatment Technologies. Washington State Department of Ecology, Olympia, WA. Publication Number 10-03-004. www.ecy.wa.gov/biblio/1003004.html.

About The Authors
Melanie Redding, L.HG, a hydrogeologist, and Brandi Lubliner, PE, an environmental engineer, work for the Washington State Department of Ecology.