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Water Management

Posted on: June 16, 2022

Durham Water Department Statement on PFAS

Durham Department of Water Management logo

Drinking water quality—a national focus
The Department of Water Management (Durham Water) is in the business of protecting public health—our drinking water is safe, high-quality, and meets all regulatory standards. On June 15, 2022, the Environmental Protection Agency (EPA) issued new health advisory levels to manage the risk for a group of man-made chemicals in drinking water called PFAS (Per- and polyfluoroalkyl substances).

We want to explain EPA’s action and share Durham Water’s approach and what we have done to date. 

What are PFAS compounds?
PFAS is a class of chemicals widely used in the manufacturing of carpets, clothing, fabrics for furniture, paper packaging for food and other materials since the 1940s. They are also used for firefighting and industrial processes. The EPA says most people are exposed to these chemicals through consumer products. Drinking water can be an additional source of exposure in communities where these chemicals have entered the water supply.

EPA develops and regulates the safe levels for hundreds of compounds in drinking water. Currently, there is no federal regulation for PFAS.
 
 PFAS are a large family of compounds—up to 5,000 chemicals. EPA is focused on a small number of these compounds that may have health effects at very low concentrations, two of which are Perfluorooctanoic acid (PFOA) and Perfluorooctane Sulfonate (PFOS).

The EPA says most uses of PFOA and PFOS were voluntarily phased out by U.S. manufacturers in the mid-2000s. There are a limited number of ongoing uses, and these chemicals remain in the environment due to their persistence and the inability to degrade. This is why these compounds are often referred to as forever chemicals

What is the EPA’s Health Advisory Level and what does it mean?
It can be a lengthy process to set drinking water regulations. With science, there’s no such thing as zero, so research is important to determine an acceptable risk level for public health. A health advisory level is commonly a first step in EPA developing a regulation.

On June 15, 2022, the EPA set new Interim Health Advisory Levels for PFOA at 0.004 parts per trillion and 0.02 parts per trillion for PFOS. These are microscopic levels, trace amounts. For perspective, 1 part per trillion is equal to 1 drop in 500,000 barrels of water. These new health advisories are also below current reliable detection abilities of most scientific equipment (Scientists can currently detect PFAS compounds at 2 parts per trillion.)

Health advisories are not enforceable like regulations. Instead, the advisories are interim guidance until EPA develops a formal regulation. The health advisory level is the minimum concentration of a compound which may present health risks to an individual over a lifetime of exposure. Because there is uncertainty about the health effects associated with long-term exposure to compounds, EPA sets lower level health advisories. Sometimes, the advisory is lower than current analytical methods can detect.

EPA first issued a health advisory level for PFOA and PFOS in 2016 at 70 parts per trillion. Based on additional research, EPA has now issued the health advisory guidance for lower levels.  

What are the levels in Durham’s drinking water?
Durham Water samples our source waters and the treated drinking water leaving our treatment plants. We test the tap water quarterly for PFAS chemicals; the following levels are averages based on quarterly samples taken from February 2018 through February 2022: 

Brown Water Treatment Plant

PFAS Compound

Durham Water Monitoring Averages

EPA Health Advisory Level

PFOA

4.0 parts per trillion

.004 parts per trillion

PFOS

6.3 parts per trillion

.02 parts per trillion


Williams Water Treatment Plant

PFAS Compound

Durham Water Monitoring Averages

EPA Health Advisory Level

PFOA

4.0 parts per trillion

.004 parts per trillion

PFOS

6.4 parts per trillion

.02 parts per trillion


The other PFAS compounds for which EPA issued health advisory levels include hexafluoropropylene oxide dimer acid (HFPO-DA), otherwise known as “GenX,” and Perfluorobutane sulfonic acid (PFBS). Our monitoring results indicate levels that are well below the health advisory levels:

PFAS Compound

Durham Water Monitoring Averages

EPA Health Advisory Level

GenX

Non-detectable with current analytical methods

10 parts per trillion

PFBS

5.6 parts per trillion at both the Brown and Williams water treatment plants

2,000 parts per trillion


What is Water Management doing about PFAS?
We recognize the average level of PFOA in our monitoring is above the EPA’s new health advisory levels. Many water service providers across the country are facing the same challenges as Durham Water. That’s why research is a priority. We need to learn more, specifically through:

  • Ongoing monitoring to identify any patterns (seasonal, etc.)
  • Researching established and emerging treatment options
  • Developing practical and feasible strategies to reduce levels of PFAS as EPA develops and finalizes future drinking water standards

We will also be working with our regional partners and with state agencies to address the issue of PFAS. The lower the level, the lower the risk and as always, public health and the quality of your drinking water is our top priority.

We are always available to talk about how we produce and deliver your drinking water and the steps we take to meet all state and federal water quality standards. Durham Water is proud to have won three consecutive Best Tasting Water in North Carolina awards, and we are working diligently to focus on this new guidance to keep providing our customers with safe and clean drinking water.

About the City of Durham Water Management Department
The Water Management Department is responsible for the operation and maintenance of Durham's water supply, water treatment and water reclamation (wastewater treatment) facilities, collection and distribution systems (including meter reading), and customer billing services. The department has a wide variety of support divisions and programs to maintain the existing infrastructure that provide these integral services, and strives to be a responsible steward of the City’s physical assets. For information, visit DurhamSavesWater.org and follow @DurhamWater on Twitter and Facebook

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