NYS DOH AND UV

https://www.cedengineering.com/userfiles/UV%20Disinfection%20for%20Drinking%20Water.pdf

This worth a read, only 38 pages.

Microbial Response to UV Light

The mechanism of disinfection by UV light differs considerably from the mechanisms of chemical disinfectants such as chlorine and ozone. Chemical disinfectants inactivate microorganisms by destroying or damaging cellular structures, interfering with metabolism, and hindering biosynthesis and growth (Snowball and Hornsey 1988). UV light inactivates microorganisms by damaging their nucleic acid, thereby preventing them from replicating. A microorganism that cannot replicate cannot infect a host.

It is important that the assays used to quantify microorganism inactivation measure the ability of the microorganism to reproduce (Jagger 1967). For bacteria, assays measure the ability of the microorganism to divide and form colonies. For viruses, assays measure the ability of the microorganism to form plaques in host cells. For protozoan cysts, the assays measure the ability of the microorganism to infect a host or tissue culture. Assays that do not measure a response to reproduction may result in misleading information on the inactivation of microorganisms using UV light.

This section describes how UV light causes microbial inactivation, discusses how microorganisms can repair the damage, and introduces the concept of UV dose-response

In some of your e-mails and posts you mention and inquire about the Village's UV system, how it works and if it is reliable and or adding to poor water quality and or health effects. NYS DOH in October 2013 has mandated that all surface waters in NYS have to have UV radiation as a secondary source with Chlorine for post treatment purposes. Chlorine nor uv radiation are 100% effect. slow sand filters when ran at the optimum flow level and uniform coefficient sand is 99.99 % effect in removing cryptosporidium, post chlorine 99.9% and uv 99.9%. This is not the only health risk but also bacteria, algae toxins, viruses, pesticides etc. The state in all it's wisdom feels that the double treatment almost assures the highest rate of disinfection. This disinfection is after the filters and before the first tap in the distribution system.

All assure disinfection at the point of injection, only chlorine and a residual of 0.2 in the distribution system is consider adequate protection from leaks, backflow, main breaks, or bacteria that may grow or enter in the pipes. The chemistry and how these things actually remove or deactivate viruses and bacteria is some what complicated but the thing to know is constant monitoring, operations, and engineering and design are critical in assuring the effectiveness.

UV does not affect water quality in regards to non living substances such as iron, Sulphur, manganese, etc, Does not react with chlorine and only has effect at point of treatment. Chlorine does add to health and poor water quality, reacting with organic and inorganics, THM's trihalomethanes, and other corrosive compounds are formed which may cause health effects and or corrosion ( thus a corrosion control program is necessary).

Ilion's issues both with chlorine and UV are poor engineering, poor operations, poor understanding of raw water quality, and not knowing or being able to treat all the variables that exist. Thus the reason for poor water quality and lead and other metals leaching from pipes.

MVWA can eliminate the multiple raw water issues, but the distribution system is still in need of a corrosion control program. MVWA superior engineering, treatment , and management has met that no violations currently exist in corrosion control in the 18 municipalities they serve.

The choice is easy only they can be trusted to assure that water quality is safe and meets standards. they are state certified lab, Ilion is not, they have hundreds of millions in treatment, capitol improvement and engineering and technology at their disposal. Ilion does not.

If it is all about safety, then the choice is clear.

David Murray Ilion