Group B Water Systems: Current Rules:
Group B water systems serve fewer than 15 connections and fewer than 25 people per day. Construction of Group B systems are approved by the State Department of Health and regulated by Mason County Environmental Health with a few state requirements such as routine testing. Some wells have water rights or a permit from Ecology to use water, others are exempt wells meaning they can withdraw a maximum of 5,000 gpd without a permit which typically serves six homes or less.
Routine water quality testing requirements include bacteria testing once a year and nitrate testing every 3 years. The District tests coliform in the spring and in the fall to ensure the water quality of our customers. If a sample is positive for coliform (total, fecal or E. coli), we are required to take additional samples within 24 hours. If the bacteria are total coliform, the system is chlorinated for a period of time. If the bacteria are fecal coliform or E. coli, the customers are notified of a boil water advisory, the system is chlorinated for a period of time, flushed then the District searches to identify the source of contamination.
By current law, the District is only required to notify customers within 14 days of contamination. For fecal and E. coli, we treat our Group B customers like our Group A customers and notify them within 24 hours. If the source is contaminated, the system may be required to permanently chlorinate. If no source of contamination is found, the system is chlorinated, flushed and tested until the samples are clear of bacteria. Once a set of five samples return satisfactory, the system can come off temporary chlorination. The next month, five samples need to be taken.
Draft Rule Changes
Proposed rule changes increase design requirements, but remove routine testing requirements. Public notification will be required within 24 hours of a positive E. coli sample, a nitrate sample exceeding 10 ppm, the well floods or other threat of acute contamination.
Submitted by Jocelyne Gray, PE
Director of Operations - Water
Mason County PUD No. 1
Mason PUD 1 on Environmentally Sound
Group B Water Systems: Current Rules:Group B water systems serve fewer than 15 connections and fewer than 25 people per day. Construction of Group B systems are approved by the State Department of Health and regulated by Mason County Environmental Health with a few state requirements such as routine testing. Some wells have water rights or a permit from Ecology to use water, others are exempt wells meaning they can withdraw a maximum of 5,000 gpd without a permit which typically serves six homes or less.
Routine water quality testing requirements include bacteria testing once a year and nitrate testing every 3 years. The District tests coliform in the spring and in the fall to ensure the water quality of our customers. If a sample is positive for coliform (total, fecal or E. coli), we are required to take additional samples within 24 hours. If the bacteria are total coliform, the system is chlorinated for a period of time. If the bacteria are fecal coliform or E. coli, the customers are notified of a boil water advisory, the system is chlorinated for a period of time, flushed then the District searches to identify the source of contamination.
By current law, the District is only required to notify customers within 14 days of contamination. For fecal and E. coli, we treat our Group B customers like our Group A customers and notify them within 24 hours. If the source is contaminated, the system may be required to permanently chlorinate. If no source of contamination is found, the system is chlorinated, flushed and tested until the samples are clear of bacteria. Once a set of five samples return satisfactory, the system can come off temporary chlorination. The next month, five samples need to be taken.
Draft Rule Changes
Proposed rule changes increase design requirements, but remove routine testing requirements. Public notification will be required within 24 hours of a positive E. coli sample, a nitrate sample exceeding 10 ppm, the well floods or other threat of acute contamination.
Submitted by Jocelyne Gray, PEDirector of Operations - Water
Mason County PUD No. 1