1. Industrial Pollutants in the Haw: Community Impacts and Action
Source Tracking to Inform Preventative Policy
Emily Sutton, Haw Riverkeeper // Haw River Assembly
PFAS levels in Surface Water
Community Action and Policy Recommendations
Sample Locations
After data analysis, informative community meetings were held in Pittsboro to address the issue of contaminated drinking water. Over fifty concerned community members attended, asked questions, and were given our data. We have partnered with Duke University and NCSU to conduct follow up sampling events in individual homes and through different filtration systems.
Recommendations for Town of Pittsboro:
Establish an interconnect with Chatham County to supply drinking water to Pittsboro residents sourced from Jordan Lake
Pressure upstream dischargers to limit PFAS levels through pretreatment programs, testing of biosolids before application, and testing leachate before accepting into waste stream.
Recommendations for Department of Environmental Quality:
Require NPDES permit holders to disclose PFAS compounds in permit
Set water quality limit on PFAS as a class in Triennial Review
Set discharge limits on PFAS as a class in discharge permits
Require land applied biosolids permit holders to sample and characterize PFAS in sludge
Add PFAS monitoring requirements for all Significant Industrial Users (SIU) using pretreatment programs
Figure 1
The quantity of shorter chain PFAS compounds was much higher in Bynum (Figure 1), where the town of Pittsboro supplies its drinking water directly from the Haw River. These sources are likely from the increase in land applied biosolids sourced from Burlington, which has a combined industrial and residential waste stream. Burlington is a textile industry hub, and many Significant Industrial Users sending pretreated wastewater to the wastewater treatment plant produce specialty textiles and products which are known to contain high levels of PFAS compounds. These compounds are not removed in traditional drinking water treatment processes (Figure 2).
Suspected Pathways of Contamination
Seasonal and Flow Rate Variation
Wastewater Treatment Plants (WWTP)
Many WWTPs in the Haw River watershed have a combined residential and industrial waste stream. In these instances, a plant often have more than fifty Significant Industrial Users (SIU) adding the the waste stream. These SIUs are subject to a pretreatment program, but do not monitor for PFAS compounds. Additionally, many WWTPs accept landfill leachate, which has not been tested for PFAS compounds.
Land Applied Biosolids (Sludge)
Residuals from these combined stream WWTPs contain concentrated levels of industrial pollutants that do not cling to water. These compounds are then land applied to fields, often directly adjacent to surface water. Exposed to wind and rain, these compounds can quickly leach into neighboring streams.
Individual NPDES from known specialty textile industries
The Haw River watershed is a traditional textile center in the state. Guilford and Alamance counties produce many specialty textiles that are water and fire resistant, which are known to contain PFAS compounds.
Figure 4
Sampling Locations
Discharge Locations*
Land Applied Biosolids**
*Discharge locations marked are limited to targeted sampling events. Samples were collected above and below each marked location. These locations were targeted due to the high levels of PFAS associated with industries discharging into surface water, often through combined residential and industrial waste streams at public wastewater treatment plants
**Many of these biosolids are sources from wastewater treatment plants with combined waste streams. The residual solids are likely to contain concentrated levels of PFAS compounds.
Figure 3
In times of low flow, when the Haw is often up to 80% effluent dominated, PFAS levels are detected in higher concentrations due to high levels released in discharges. Notice the higher levels in the finished water in September following high levels in July (Figure 3). Filtration systems seek equilibrium: if a filter had previously processed high concentrations of PFAS, the filter could release those stored compounds when lower levels are present in raw water.
Sample analysis conducted by Detlef Knappe, Zachary Hopkins, Amie McElroy (NCSU)
Figure 2