Presentations & Reports
Presentations at Conferences and Meetings
- Plumbing Manufacturers International Conference, November 2019
- American Chemical Society National Meeting, August 2019
- Drinking Water and Plumbing Public Meeting - Paradise CA, June 2019
- The National Academies of Sciences, Engineering, and Medicine, June 2019
- American Water Works Association (Platform-School Water Quality), June 2019
- American Water Works Association (Platform-Home Water Quality), June 2019
- EES Symposium, April 2019
- VOC Fate in Water Systems prepared for CA Camp Fire Task Force, March 2019
- AWWA Distribution Systems Subcommittee 'Beyond the Meter', December 2018
- US Green Building Council Greenbuild, November 2018
- Plumbing Manufacturers International Conference, November 2018
- Indiana Water Environment Association Conference (Chemical Quality), August 2018
- Indiana Water Environment Association Conference (Transition), August 2018
- National Environmental Health Association Conference, June 2018
- American Water Works Association (Poster), June 2018
- American Water Works Association (Platform-Chemical Quality), June 2018
- American Water Works Association (Platform-4 Month Fixture Use), June 2018
- Emerging Water Technologies Symposium, April 2018
- American Council for an Energy-Efficient Economy Hot Water Forum, March 2018
- American Chemical Society Spring Meeting, March 2018
- US EPA Project Progress Meeting - Year 1, December 2017
- Society of Risk Analysis Conference, December 2017
- U.S. Green Building GreenBuild Conference, November 2017
- USEPA Water Workshop, August 2017
Camp Fire Disaster Opinions
- Opinion (June 16, 2019) to the California Governor's Office of Emergency Services and State Water Resources Control Board about the plumbing testing guidance issued June 14, 2019
- Opinion (March 26, 2019) to the California Governor’s Office of Emergency Services (CalOES) Camp Fire Water Task Force describing considerations for decontaminating high-density polyethylene (HDPE) services lines by flushing
- Opinion (March 24, 2019) to the California Governor's Office of Operations of Emergency Services (CalOES) with respect to their need for clarity on Camp Fire Waste handling
- Opinion (March 11, 2019) to the State Water Resources Control Board with respect to their decisions regarding drinking water Camp Fire response and recovery
- Opinion (February 20, 2019) describing recommendations for agencies responding to the Camp Fire drinking water contamination
- An investigation of spatial and temporal drinking water quality variation in green residential plumbing. 2019. Building and Environment. Available at https://doi.org/10.1016/j.buildenv.2019.106566 or contact us for a copy.
Water quality at cold and hot water faucets was characterized during 1 year in a highly instrumented residential home. More than 2.4 billion online monitoring records were collected for fixture flow and temperature and online water quality monitoring was conducted as water entered the building too. During the year, water samples at the home were collected for 58 days - before water entered the building and inside the building for cold and hot water. More than 222,000 labor hours were needed by 30 Purdue University and Michigan State University students, faculty, and staff to conduct this monitoring - not including data analysis and interpretation.
- Drinking water quality entering the building varied by season.
- For 10.3% of the year's water sampling events, drinking water entering the building did not contain a detectable chlorine disinfectant residual.
- Inside the building, water stagnation time varied seasonally and across fixtures. Water at the kitchen sink in the Summer had different characteristics than water in the Winter. For example, cold water at the bathroom sink had different characteristics than water at the kitchen sink.
- Water pH also consistently and significantly increased in the plumbing from 7.5 to 9.4, and total trihalomethane (TTHM) levels increased up to 89%.
- Drinking water organic carbon entering the building was consistent (0.5-0.6 mg/L), but much greater variability was found inside the building for cold (0.4-61.0 mg/L) and hot water (0.5-4.7 mg/L).
- Models are needed to predict chemical water quality at the faucet using service line water quality results and plumbing design and operational information. Building water sensor technology innovations are also needed.
- Corrosion of upstream metal plumbing components impact downstream PEX pipe surface deposits and degradation. Chemosphere. 2019. Available at https://doi.org/10.1016/j.chemosphere.2019.07.060 or contact us for a copy.
Six-month old galvanized iron pipes (GIPs) and downstream crosslinked polyethylene (PEX) pipes were exhumed from a residential home. Follow-up bench-scale experiments revealed that metal levels in the drinking water did not always predict metal loadings on plastic pipe surfaces. This study highlights potential downstream plastic pipe degradation and metal deposition, which may cause plumbing problems and failures for building owners, inhabitants, and water utilities.
- CuO, Cu(OH)2, FeOOH, Fe2O3, and MnO2 were found on exhumed PEX pipe surfaces.
- Moderately aggressive water at 55 °C resulted the greatest metal loading on plastic surfaces.
- PEX pipes exposed to hot water released more organic carbon than cold water.
- PEX pipes connected to copper and brass had the greatest plastic surface oxidation.
- Case Study: Fixture water use and drinking water quality in a new residential green building. Chemosphere. 2017. Available at https://doi.org/10.1016/j.chemosphere.2017.11.070 or contact us for a copy.
Testing was conducted in a newly renovated single-family home for the first 4 months of use. The plumbing system was PEX type A pipe installed using trunk-and-branch design. More than 64 million data points were collected related to fixture water use and were analyzed. Drinking water sampling was conducted periodically at various locations in the home. Water was tested for both chemical, microbiological, and odor characteristics.
- During the study, the maximum fixture water stagnation time was 72 hours.
- Hot water contained greater levels of bacteria and organic carbon than cold drinking water.
- Chemical and bacteria levels varied across fixtures within the building.
- Pb, Fe, and Zn exceeded EPA standards, but only at the least frequently used (and monitored) fixture in the basement.
- Metal Accumulation in Representative Plastic Drinking Water Plumbing Systems. Journal of the American Waterworks Association. Available at https://doi.org/10.5942/jawwa.2017.109.0117 or contact us for a copy.
Heavy metal abundance and scale morphology for cross‐linked polyethylene (PEX) plastic pipes and pipe oxidative condition were examined in a one‐year‐old residential plumbing system.
- Metals found on the plastic pipes (Al, Ca, Co, Cu, Pb, Mg, Mn, Ni, Se, Zn) were corrosion products from drinking water distribution and plumbing materials and were present in the source water.
- Fe was the most abundant contaminant on pipes.
- Plastic served as a nucleation site for Fe crystal growth and expedited crystal formation.
- Plastic plumbing pipes can adsorb metals that have health and aesthetic drinking water limits, and additional work is needed to understand the conditions that affect metal accumulation and release.
External Public Reports by Others
Camp Fire Plumbing Testing Procedure (Version 3) Recommended by the State of California, August 2019
Camp Fire Plumbing Testing Procedure (Version 2) Recommended by the State of California, June 2019
State of California Short-Term Benzene Exposure Risk Assessment, April 2019
State of California Press Release Falsely Claiming Del Oro Water Company Never Had Contamination, March 2019
Camp Fire Drinking Water Odor Dissipation Study Conducted by the State of California, March 2019
State of California Unsafe Water Notification Guidance, April 2018