Septic System Effluent, an Unconstrained Source for Pharmaceuticals and Personal Care Products (PPCPs) in Ground and Surface Water

EPA Grant Number: F5B20266
Title: Septic System Effluent, an Unconstrained Source for Pharmaceuticals and Personal Care Products (PPCPs) in Ground and Surface Water
Investigators: Dougherty, Jennifer A.
Institution: Stanford University
EPA Project Officer: Hahn, Intaek
Project Period: September 26, 2005 through September 25, 2007
Project Amount: $74,344
RFA: STAR Graduate Fellowships (2005) RFA Text |  Recipients Lists
Research Category: Academic Fellowships


Emerging contaminants like pharmaceuticals and personal care products (PPCPs) are a significant threat to ecosystem health and function. Nearly one quarter of waste generated in the United States is disposed of via septic systems. The potential of PPCP contamination from this waste has not been previously addressed. Both functioning and malfunctioning septic systems can play a role in the transport of PPCPs. This effluent may contaminate shallow groundwater and be transported into surface waters with some direct conduits to the ocean or lakes. I will test the hypothesis that under certain conditions, PPCPs will make their way through properly functioning septic systems and, therefore, be transmitted to either surface or ground waters. In addition to functioning systems, improperly functioning septic systems will allow even greater concentrations of PPCPs to pass. Septic system contamination can severely impact surface and ground water and eventually the entire aquatic environment.


The objectives will be addressed through field sampling coupled with laboratory analyses and experiments. The preliminary list of PPCP compounds includes previously documented compounds detectable in waste water treatment effluent among other waters Analysis of target compounds will be a combination of previously detailed methods for GC/MS or LC/MS.

The proposed field site is the area surrounding Tomales Bay, California. The area includes homes or government facilities with septic systems adjacent to streams and groundwater wells. The sampling strategy will be to sample at least twice, once during a high precipitation event, the other during low flow conditions. Six general kinds of samples will be evaluated:

  1. several local control samples for background PPCP concentrations in wells, streams and the bay;
  2. influent and effluent from several septic tanks, ideally in a confined area adjacent to a stream and nearby groundwater wells;
  3. water from leach fields of septic tanks;
  4. groundwater from nearby wells and springs;
  5. surface runoff in an area isolated from agricultural influence;
  6. within the estuary near the discharge area of a stream.

Expected Results:

This study will assess the baseline PPCP contamination in the Tomales Bay area, as well as within the Bay where I suspect an impact from septic system contamination. The results of this study can be extrapolated to estimate PPCP contamination via septic systems nationwide. PPCPs are a significant threat to ecosystem health and function. The results of this study will bridge the gap in PPCP contamination studies affecting our national waters and provide more information to understand the persistence and fate of PPCPs.

Supplemental Keywords:

fellowship, pharmaceuticals and personal care products, PPCPs, emerging contaminants, environmental contaminants, septic system, onsite waste disposal, effluent, fate and transport, contaminant transport, environmental chemistry, GC/MS, LC/MS,, Scientific Discipline, Water, Wastewater, Environmental Chemistry, Environmental Monitoring, overflows, septic system effluent, chemical contaminants, municipal wastewater, groundwater contamination, field sampling, effluents, pharmacuticals

Progress and Final Reports:

  • 2006
  • Final