Drinking to your health: is your outside drinking fountain safe? Take a look at some of the issues involved with ground water contamination

Parks & Recreation, Jan, 2005 by Herb Hoeptner

If you use or install outside drinking fountains or yard hydrants, you might want to concern yourself with the inevitable possibility that your potable water can become contaminated with harmful bacteria located in the soil. You hire the best contractors and assume that you meet all the state and local requirements, but sometimes it isn't enough.

Some code authorities adopt codes but don't necessarily enforce them, leaving you liable for any problems that develop. Some code authorities are slow to adopt the most current standards available, thus newly adopt an old standard after you have completed your project, again leaving you liable. In this litigious society, sometimes you need to do more to ensure you do not become entangled in a court case.

Typical outside drinking fountains and yard hydrants prevent freeze-ups by draining out of a "weep hole" deep in the ground. They generally consist of a bubbler, or in the case of a yard hydrant, a head for attaching a hose, a riser pipe and a shutoff valve deep below the frost level. The term "weep hole" is derived from the fact that, when the weep hole drinking fountain or yard hydrant is shut off, a hole in the side of the valve opens to drain all the water from the riser into the soil below the frost line. These are also referred to as Stop & Waste valves.

A typical problem for these "weep hole" devices is that, when the ground water level fluctuates, especially during the summer months, or the device is used repeatedly so drain water does not have a chance to percolate into the ground, the ground water level will rise above the weep hole, filling the riser with soiled ground water that will be consumed by the public, Each time the device is shut off (Fig. 1) and the weep hole opens, ground water will migrate into the drinking fountain or yard hydrant. Each time the drinking fountain or hydrant is turned on (Fig. 2), that contaminated migrated water enters the potable water supply system and exits the bubbler. That first drink of water can be nothing but soiled, most likely contaminated water.

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A secondary, and more serious, problem occurs when the rubber seal in the shutoff valve or air valve deteriorates over time and begins to leak. When the valve on the kitchen sink leaks, it is very noticeable as it will drip incessantly forcing you to replace the rubber seal. Unfortunately when your drinking fountain or yard hydrant leaks, it usually leaks out the weep hole deep in the ground undetected. From the surface no one is aware the device is leaking. When a back siphonage condition occurs (Fig. 3 on the next page), that leak out will become a leak in, sucking contaminated muddy water into the supply line. If the hydrant is located in a horse arena or cow barn, animal by-products will leach into the potable water supply

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In the first scenario, the end user can consume contaminated water. In the second scenario, it is far more serious because the entire water supply can become contaminated, which the public consumes. This means that possible contamination from one drinking fountain or yard hydrant, in one area, could cross contaminate the public in other areas or other commercial or private dwellings. Anyone connected to that water supply potentially can become contaminated.

Lately, due to the deaths associated with e-coli outbreaks and other pathogens that have contaminated our water supplies, there has been great concern regarding cross contamination between the soil, which carries animal by-products, fertilizers and other waste, and the water supply.

The liability toward each state became such a concern that many states created their own drinking fountain and yard hydrant requirements. Initially, states implemented requirements to isolate weep hole devices from the potable water supply. These requirements included installing a testable RPP backflow preventer upstream of the hydrant and then tagging the hydrant "danger unsafe water." This solved two concerns.

First, it protected the potable water supply from siphoning contaminated water into the public water system, and secondly, it attempted to notify the public not to use the hydrant for any potable source. Naturally the obvious downside to this approach was that drinking fountains and yard hydrants had to be used as a potable source. Drinking fountains are only used for drinking, and yard hydrants are used for RV parks and campgrounds. A secondary downside is the cost associated with the purchase and installation of a testable RPP backflow preventer, the difficulty in finding a location for the backflow preventer to keep it from freezing, and the added cost in annual inspection and testing of the device.

Innovative manufacturers soon developed a new breed of drinking fountains and yard hydrants to solve the problems associated with the new requirements imposed on weep hole devices. These new devices are called Sanitary Drinking Fountains (Fig. 4) and Sanitary Yard Hydrants.

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