Updated: Jun 30, 2019
About the Event
Experts in plumbing and engineering from Purdue University held a community event entitled "Drinking Water and Plumbing After the Camp Fire" on Thursday June 27, 2019 at the Paradise Alliance Church. Water contamination has been found in the water distribution systems of both Paradise Irrigation District (PID) and Del Oro Water Company after the Camp Fire. Both water supply companies are working hard to understand the extent of water contamination with ongoing testing and to resolve the contamination issues within their districts, but it will take time. Water contamination presents challenges for those in standing homes, those living in temporary dwellings (like RVs) on property where a structure burned, and those rebuilding.
The Drinking Water and Plumbing After the Camp Fire event had two parts. The first part of the event featured interactive stations hosted by experts to give attendees an opportunity to learn about plumbing and water with hands-on examples and activities and to ask questions. The second part of the event presented the results of the Camp Fire Drinking Water Survey, details of that presentation can be found at the end of this article. The aim of this post is to share some of that hands-on learning with those unable to attend in person. Click here to read more background on the water contamination issue.
Event Hosts: Dr. Andrew Whelton and Dr. Caitlin Proctor, along with three graduate students (Tolulupe "Tolu" Odimayomi, Christian Ley, Yoorae Noh) and an undergraduate research student (Qi Erica Wang) all from Purdue University's Division of Environmental Engineering were flown out to host the event via funding from the Paradise Rotary Foundation. Joining the team of experts to host the event were Dr. Jackson Webster from CSU Chico's Department of Civil Engineering, Dr. Charlotte Smith from the UC Berkeley School of Public Health, and Jim Smith, a retired water treatment operator from East Bay Municipal Water District. Also among the experts were Dr. Kristin Milinkevich and Dr. Michael Lodewyk from the Chemistry Department at Butte College as well as Julie Jenks from the Biology Department at Butte College (and a Zone Captain), all of whom were directly impacted by the Camp Fire.
There were four stations: Plumbing Zoo, Plumbing Damage, Water Sample Challenge, and Ask the Experts! Each one is described in more detail below.
The diagram below illustrates the difference between the water company mains (dark blue) and water company service lines to the meter (light blue). These are owned by the water supply companies. Water companies are responsible for their water testing and decontamination/replacement, not the property owner. The customer however IS responsible for the customer service line (black) as well as the irrigation pipes and pipes and fixtures within the structure, testing and/or replacement are the responsibility of the property owner. Property owners are responsible for water testing of those items and decontamination/replacement, not the water company.
Volatile organic compounds are called VOCs, which have been detected in the PID and some Del Oro water systems. Finding if they are in plumbing and removing them was the focus of this event. When VOCs settle onto the surface of a material, that is called ADSORPTION. These chemicals can often be rinsed away easily. VOCs can also ABSORB into plastics like pipes and gaskets. The absorption process involves VOCs penetrating into the plastic much like a sponge. VOCs DO NOT penetrate metal materials like pipes, fittings, and valves. Those materials are too dense. VOCs only settle on the metal surface. All metal and plastic plumbing materials however will develop what is called a biofilm. This is a very thin slimy layer of microorganisms growing on the moist surface. Some VOCs are able to absorb into the biofilm.
Even supply lines for toilets or faucets that appear to be made of metal can be made of braided metal material wrapped around plastic pipe (seen below toward the left). This image also shows some of the different filter materials that may be used for in-home water filtration.
It was also emphasized that the cold water and hot water that mix at your kitchen sink faucet or shower head run through the building in completely separate sets of pipes.
Water meters, meter covers, gauges, and service lines damaged by the Camp Fire provided to the Purdue team by PID and Del Oro Water Company were displayed. Tolu Odimayomi explains the damaged materials in the video below.
Absorption and Desorption of VOCs
VOCs like benzene and other chemicals detected are only slightly soluble in water. Their chemical properties allow them to be adsorbed onto metal and plastic surfaces. But, VOCs can also ABSORB into plastic service lines, pipes, gaskets, fittings, and fixtures. ABSORPTION is the process where chemicals travel into or permeate the plastic. Once VOCs are inside the plastics, they can also leach out from these materials and enter drinking water. This is called DESORPTION. Since VOCs can't be seen with the eye, this is difficult to visualize. The demonstration showed participants sponges ABSORBED red dye (much like plastics would absorb VOCs). Then those contaminated sponges were placed in clean drinking water and the color of the water darkened with time. The longer the soak time in clean water the more red dye had leached into that previously clean drinking water. This demo illustrates why stagnation (allowing the water to sit unused in the pipes) can allow more chemicals to enter the drinking water from the plastic. Therefore, allowing the water to sit before taking a sample is crucial to get an accurate reflection of the level of contamination present in plumbing. Another demo showed how a higher water temperature increased the speed that VOCs can penetrate into plastics. In the video below, Tolu walks my daughters through the activities at this station.
Water Sampling for Quality Testing
While PID and Del Oro Water Company are conducting their own distribution system water testing, decontamination and/or replacement, it remains the property owner’s responsibility to test the plumbing on the customer side of the meter (if damage isn't apparent). The interactive station for water sampling allowed attendees to practice collecting VOC water samples. Normally test vials would be empty except for a preservative that will dissolve into the water as it is added during sampling. For the demo, glitter was used in place of the preservative. The water should be turned on slowly so air is not introduced to the glass vial. Then, the vial should be filled until the surface tension of the water creates a dome of water over the top of the vial. Next, the cap should be secured in place and the vial turned upside down to ensure no bubbles are present. Bubbles of air allow a place for the benzene or other VOCs to volatilize out of the water sample. If bubbles are present, the VOCs would not be detected in the water during testing even though they had been there. In the below video, Christian Ley explains to Dr. Kristin Milinkevich how to properly take a water sample.
The State of California Water Resource Control Board's Division of Drinking Water (DDW) shared guidance on June 14, 2019 for how individuals should obtain water samples for the purposes of testing for VOC contamination after wildfire. This updated guidance advises that water be stagnated for 8 hours directly prior to sampling. Note: if the water sampling procedure has you run the faucet for any amount of time before sampling, you are really clearing the water from your home's pipes and bringing in new water from the service line and/or water main and sampling that water. The aim of sampling within a structure is to look for VOC contamination within the plumbing of the home (or business), so stagnation without flushing is crucial. Click here to read the DDW's guidance.
During the presentation that followed the demonstrations, Dr. Whelton shared that he and a team of plumbing experts from five universities have submitted advice to the DDW that their guidance should be expanded (as indicated below) in order to maximize protection of public health. Click here for the full guidance document the Purdue-led team sent to DDW. The presentation slides and the video of the presentation are linked at the end of the article.
Two labs have offices in Chico and are certified to perform water testing for VOC contamination: Fruit Grower's Laboratory and Basic Laboratory. FGL is offering a 20% discount on VOC testing through September 2019.
Ask the Experts!
This station was designed to walk attendees through reading a water quality lab report as well as to answer any questions attendees may have about water contamination.
Below is a summary of water contamination data from the Tubbs Fire in Santa Rosa and data available from PID and Del Oro Water Company up to May 2019. Water testing is on-going for both PID and Del Oro and their water testing data is available on each of their websites. So far after the Camp Fire, the highest level of benzene contamination has been found in a sample obtained from a service line to a burned structure in PID's district, which was sampled and tested by the State Water Resources Control Board (SWRCB) with results at over 2000 parts per billion (ppb) benzene. Also important to note is that other VOCs (such as methylene chloride, naphthalene, styrene, tert-butyl alcohol, toluene, vinyl chloride, and others) have been detected at levels higher than exposure limits in samples in which benzene was not detected. The limits of exposure are set at lower levels to maximize overall protection of public health. The primary risk associated with exposure to lower levels of these contaminants are cancers that can develop with long-term (chronic) exposure to even very low concentrations of certain VOCs. Also listed on the chart below are the USEPA 1-day health advisory levels. These are levels above which immediate (acute) health impacts can occur after one exposure to a higher concentration of the contaminant.
Below is a sample lab report from full VOC testing of a water sample that was available for review at the event. The red squares highlight all the VOC contaminants detected in this particular sample, not only benzene.
Following the interactive demos, Dr. Andrew Whelton presented a summary of water contamination and plumbing and then Dr. Caitlin Proctor presented a summary of the results of the Camp Fire Standing Home Water Survey (click link for presentation). Following the presentation, Dr. Whelton and Dr. Proctor fielded many questions from the audience. Below is the video of the presentation that was live-streamed by the Camp Fire Zone Project (including Q&A).
Dr. Whelton and his team from Purdue have been receptive to answering water contamination questions from those affected by the Camp Fire since they became involved. If you have any questions, there is more information at their website, plumbingsafety.org as well as an email address to contact them with specific questions.