In 2004 the Guild was required to monitor its treated drinking water for levels of disinfection by products (DPBs) that are regulated by the Federal Government.  While the Guild's water was in compliance for one class of regulated DPBs, haloacetic acids (HAAs), it was substantially out of complaince for a second class, trihalomethanes (THM's).  These compounds are created by the reaction of free chlorine, which is added to kill portentially harmeful microbes, with organic precursors present on the raw surface water.  THM's are suspected human carcinogens. 

A new filter treatment plant was installed in 2005, which made an improvement but did not bring the system into compliance.  Further attempts to decrease THM's by lowereing organic precursors levels through  improved management of reservoir water were also not successful. 

In August of 2006 the Guild received a Notice of Violation and entered into an agreement with DPH to mitigate THM levels by hiring a water treatment engineering firm to evaluate mitigation alternatives, followed by implementation of an effective alternative.

Water Quality Treatment Solutions (WQTS), was hired in November of 2006.  After a site visit in December, and consultations with Guild staff and volunteers in the winter of 2007, an evaluation plan was developed and implemented starting in the spring of 2007.  When this evaluation was completed in the fall of 2007, a switch to chloramine as an alternative disinfectant was reccomended as it was the only tested alternative that showed promise of bringing the Guild into compliance. 

Chloramine is a mixture of ammonia and chlorine.  It lowers THM and HAA levels because it is slower to react with precursors than is free chlorine.  Engineering of a chloramine disnfection system began in the winter of 2008. 

In the summer of 2008, a new mitigation alternative, aeration, was brought to the Guild's attention by our Chief Water Treatment Operator, and again in the fall of that year by a Guild member.  Aeration has only been installed in a handful of water systems to mitigate DPB's,

n the second quarter of 2010, the Guild came into compliance for levels of trihalomethanes in its treated drinking water for the first time since monitoring was required in 2004.