BY JACK SHORT – The Gasparilla Island Water Association would like people to be aware that rules, whose formation began in 1992, have gone into effect that may affect some of their stakeholders on the island.
According to a GIWA representative, the rules, developed by the Florida Department of Environmental Protection, determine the kinds of backflow-prevention devices people must use if they meet certain conditions.
Homeowners will be notified by GIWA if they need to update or install prevention devices, though there is no timetable for when that will be.
To complicate matters, necessary measures will depend on homeownwers’ plumbing, for example whether or not users have irrigation wells that are interconnected to GIWA water.
Even a home with a garden hose can cause backflow under certain circumstances.
Backflow, or the movement of water from delivery sites backwards into GIWA’s water supply, can be caused by either back-pressure or back-siphonage, according to a representative of GIWA.
In the first case, pressure at a home or business may force contaminated water back into GIWA’s supply. In the second, a drop in pressure on GIWA’s end my pull water back into its supply from homes and businesses.
For example, a garden hose used to fill a pool may siphon water back into the association’s water supply if they experience a drop in pressure at their facilities.
GIWA’s water supply is subject to changes in pressure, caused by event such as water-main breaks, that could lead to back siphonage, according to GIWA.
In 2014, according to GIWA, a meter at an island home registered in reverse, which alerted the association to the backflow. That home had a backflow prevention device in place, but it wasn’t effective against backflow from an irrigation system drawing water from a cistern.
GIWA turned the meter off and stopped the flow before checking chlorine and bacteria levels. They found no contamination.
Different devices can be put in place depending on whether or not a customer uses a well, whether or not that well is interconnected, and other circumstances.
A simple dual-check device, installed at a home’s water meter, has a one-way valve in it to prevent backflow and will satisfy requirements in some circumstances, but it must be replaced every five years, according to the new rules. Additionally, like many backflow prevention devices that protect GIWA’s water supply from contamination, they may not prevent backflow into a home or business.
A longer-lasting, above-ground device can be installed as well, and may be required if, for example, a well is used and is interconnected to GIWA’s supply.
As GIWA replaces meters for their meter changeout program, they will notify customers if action needs to be taken. Meters are changed out on a ten year cycle; this year, they hope to change out 200 meters. They will also notify owners of newly purchased property on the island if modifications need to be carried out.
In the meantime, GIWA recommends installing vacuum breakers on hoses. If users have an interconnected well, they should consult a plumber.
Homeowners are responsible for the cost of installation of any needed devices. GIWA tests devices for free in the case of above-ground, testable units. Commercial properties are tested every year, and homes are tested every two years.