Biofilm is a low cost shortcut, yielding mild and erratic lead concentration reductions. Peer-reviewed science shows that Flint needs to eliminate fluoridation, and/or replace all lead piping and brass plumbing fittings that contain lead
- Michigan Radio – (12/10/15) – “Flint fights lead drinking water adding more phosphates” – Adding more phosphates to the water should help create a biofilm within the city’s water pipes. That should help alleviate our lead issues out in the system. This approach is countered by:
- Journal of Environmental Engineering (2016) – “Impact of Zinc Orthophosphate on Simulated Drinking Water Biofilms Influenced by Lead and Copper” – The bulk water phase of galvanic cells, which simulate partially replaced lead service lines, had highly variable lead concentrations. Most were well above 15μg/L, as orthophosphate concentrations were increased through 3 mg/l. Biofilm lead concentrations consistently decreased as orthophosphate increased. See Table 2.
- International Journal of Environmental Research and Public Health (2013) – “An Evaluation of Microbial and Chemical Contamination Sources Related to the Deterioration of Tap Water Quality in the Household Water Supply System” Both chlorination and microfiltration reduced biofilm formation, as measured by HPCs on pipe walls. After inspection of the internal surfaces in PVC systems, significant pipe loss was observed on pipe surfaces after 1 years of operation, and VOC substances, such as vinylacetate, NN-DMA, cis-1,2-dichloroethylene, epichlorohydrin, and styrene were identified in five kinds of plastic pipes (PVC, PB, PP, PE, and cPVC)… The levels of released metal from plastic pipes were monitored in five pipe systems, PB, PVC, PP, PE, and cPVC. The metal levels in new plastic facilities were not serious except for PVC and cPVC, respectively. 6 μg/L of tin and 2.7 μg/L of lead were detected in new cPVC and PVC pipe in this experiment.
- Applied and Environmental Microbiology (2011) –“Microbial Community Profile of a Lead Service Line Removed from a Drinking Water Distribution System” – Despite evidence that high and consistent levels of chlorine have been present at the pipe surface, a biofilm is still present and presumably active… The activity and properties of biofilm are thought to contribute to the corrosion and release of metals from drinking water distribution system materials, including lead.
- Thesis – Dalhousie University – Halifax, Nova Scotia (2013) – “Interactions of corrosion control and biofilm on lead and copper in premise plumbing” -The hypothesis that biofilm contributes to lead and copper release in premise plumbing was demonstrated in two ways: 1) biofilm acted as a storage site for released lead and copper and 2) lead particles provided surface area to support increased biofilm growth… Additionally, downstream inert plumbing fixtures may act as accumulation sites for metals from upstream processes. There is a risk of accumulation in downstream plumbing biofilms. Since changes in water quality and flow patterns can affect corrosion scales and biofilm stability, it’s important to understand the water chemistry and operational conditions that ensure the greatest stability to these storage sites.
- Applied Environmental Microbiology (2011) – “Comparing the Chlorine Disinfection of Detached Biofilm Clusters with Those of Sessile Biofilms and Planktonic Cells in Single- and Dual-Species Cultures” – Biofilms are also characterized by the active or passive detachment of cell and clusters. Depending on the species composition and mechanical biofilm stability, increased shear forces can lead to detachment of biofilm clumps, which may be enhanced when treated with oxidizing disinfectants such as chlorine.
- National Water Research Institute (1998) – “Interactions between pipe materials, organics, corrosion inhibitors, and disinfectants on distribution biofilms” – The use of phosphorus based corrosion inhibitors increases the phosphorus levels in the distribution system which is of concern because phosphorus is one of the essential nutrients for microbial growth… The implementation of treatment changes terrifies many water utilities because of the lack of technical guidance on how these changes will impact the microbial water quality in the distribution system.
- Water Research (2014) – “Drinking water quality and formation of biofilms in an office building during its first year of operation, a full scale study” – Complex interactions existing between water distribution systems’ materials and water can cause a reduction in water quality and unwanted changes in materials, aging or corrosion of materials and formation of biofilms on surfaces… Brass components were considered to be a source of leaching; e.g. the lead concentration was highest during the first few weeks after the commissioning of the pipe network when the water was allowed to stagnate… Microbiological quality of water was found to deteriorate due to stagnation.
- Environmental Science Technology, Center for Biofilm Engineering (2009) – “Lead contamination of potable water due to nitrification” – At 100 mg/L alkalinity as CaCO3, complete nitrification did not significantly decrease pH (pH stayed>7.5) or increase lead contamination of water for lead pipe, but at 15 mg/L alkalinity, nitrification decreased the pH by 1.5 units (pH reduced to<6.5) and increased soluble lead contamination by 65 times. Lower pH values from nitrification also leached 45% more lead and 81% more zinc from leaded brass connected to PVC pipes relative to the same situation for copper pipes. Alkalinity as CaCO3 of Flint River water often 30 to 40.
- Virulence (2011) – “Staphylococcus aureus biofilms – Properties, regulation and roles in human disease” – Staphylococcus aureus is the etiological agent to a myriad of human acute infections, however, its ability to form biofilm in host emanates into chronic and recalcitrant disease. Current therapies for treating and preventing chronic biofilm-mediated infections are limited to surgical intervention and prolonged antibiotic regiments or addition of antimicrobial compounds to indwelling-medical devices.
- BioMed Central Microbiology (2011) – “Interaction of legionella pneumophila and helicobacter pylori with bacterial species isolated from drinking water biofilms” – Legionella pneumophila is a waterborne pathogen that can cause Legionnaires’ disease or Pontiac fever. This pathogen is found naturally in fresh water reservoirs and can contaminate drinking water when disinfection is inefficient, being transmitted to man when contaminated aerosols are inhaled… Previous studies have demonstrated that both pathogens can be incorporated into heterotrophic drinking water biofilms and persist for at least 32 days… After two weeks the cultivability decreased but was not completely lost for the 32 days of the experiment which indicates that biofilms are a protective niche for L. pneumophila, even in axenic culture.
- Journal of the American Medical Association (1988) -“Chlorination of Water Supplies to Control Legionella May Corrode the Pipes” Following two major outbreaks of legionnaires’ disease at this institution in 1980, continuous hyperchlorination of the hospital’s hot water system was begun in 1981, with attempts made to maintain chlorine levels of 1.5 mg/L of free chlorine. Although Legionella could no longer be cultured from hot water samples, by 1984 major corrosion damage to the copper plumbing system had occurred, resulting in unacceptable maintenance costs, disruption of patient care activities, and concern about disintegration of the entire water distribution system.
- Biofouling (2009) – “Comparison between standard culture and peptide nucleic acid 16 S rRNA hybridization quantification to study the influence of physico-chemical parameters on Legionella pneumophila survival in drinking water biofilms” – A comparison of the two temperatures showed that at 15 degrees C, the total cell numbers for L. pneumophila were generally higher compared with the total microbial flora, suggesting that lower temperatures support the inclusion of L. pneumophila in drinking water biofilms.
Fluoride-Free Flint 