Dr. Gagnon: VNA’s recommendations to the City of Flint were consistent with scientific knowledge
On June 13, 14 and 16, 2022, Dr. Graham Gagnon testified in court. Dr. Gagnon is a civil engineering professor in the Department of Civil & Resource Engineering at Dalhousie University and an expert on drinking water quality and treatment. He has over 25 years of experience and has worked on drinking water research projects across Canada and the United States.
Dr. Gagnon’s report studied the sources of lead in Flint’s drinking water and found that the dissolution of pipe scale caused the majority of lead release in Flint, and that this elevation occurred after the water switch in April 2014 — well before VNA had even arrived in Flint. Dr. Gagnon further testified that VNA’s recommendations to the City – including treatment practices for removal of organic matter and corrosion control – were consistent with scientific knowledge and would have addressed Flint’s lead issues had they been implemented.
Here’s what you need to know.
Flint’s lead issue was primarily in the distribution system, not the Flint Water Treatment Plant (FWTP) where VNA’s work occurred.
- Dr. Gagnon’s report found that lead service lines were the predominate source of lead in Flint’s drinking water, although just 16% of homes had lead service lines at the time of the switch to the Flint River.
- VNA recognized that water from the Flint River was corrosive, and therefore recommended corrosion control. However, VNA’s work was limited to the operations of the plant.
- As a result, VNA had no choice but to rely on the City to provide relevant information about lead test results and other concerns related to the distribution system.
- VNA explicitly requested this information and had no reason to believe that they had been provided incomplete and faulty data.
A spike in lead release into Flint’s drinking water occurred in the months following the City’s switch in water sources in April 2014, well before VNA arrived in Flint.
- Dr. Gagnon concluded that the lead release in Flint came predominantly from the sloughing off of scale that had accumulated on lead service lines.
- The majority of this lead was released into Flint’s treated tap water during the summer of 2014 and lead levels had significantly retreated by 2015.
- Dr. Gagnon also found that the Flint water had greater amounts of natural organic material (NOM) that can more easily dissolve lead into water and its removal was critical for effective corrosion control.
VNA’s recommendations were consistent with scientific knowledge and would have addressed the lead issues in Flint had they been implemented.
- Dr. Gagnon testified that VNA’s recommendations for minimizing NOM and implementing corrosion control treatment were appropriate and supported by scientific knowledge and industry best practices.
- Tragically, the same officials who hired VNA for their engineering expertise chose to ignore all but one of VNA’s recommendations, including the recommendation to conduct a corrosion control study to address the issue of corrosive water and the potential for lead problems.