THE HOUSE DETECTIVE

Drains and pipes

LAUNDRY WATER DRAINS INTO BACKYARD

DEAR BARRY: The home I'm buying has a bootlegged drain pipe for the washing machine, as reported by my home inspector. Instead of draining the laundry into the septic system, the pipe extends to a garden area in the back yard. The seller says he's been draining his washer this way for years and that all his neighbors do the same. I called the local building department, and they say it's illegal to drain gray water onto the ground. Should I continue to drain the washer to the back yard or connect it to the septic?

Geoff

DEAR GEOFF: Home owners with septic systems often drain their laundry water into their gardens. Although the practice is prohibited by code, it is generally regarded as a necessary trade-off to protect the continued performance of the septic system. Laundry detergents and bleach are commonly known to have damaging effects on the bacterial ecology of septic systems. "Friendly" bacteria in the septic tank are necessary for the decomposition of solid waste matter. Laundry chemicals can kill these bacteria, causing the system to become clogged with undissolved solids. Therefore, clandestine drainage to the back yard landscaping is a simple way to avoid sewage problems.

An added advantage to this illegal practice is that plants generally respond favorably to detergents, because the phosphates seem to work well as fertilizers. However, biodegradable detergents would be advisable in such cases.

If you want to drain the gray water legally, without adversely affecting the septic system, an underground leach field or sump pit can be installed in the yard.

DEAR BARRY: When I installed my back yard hot tub, I ran a galvanized steel gas pipe below ground from the gas meter to the spa heater. Now that I'm selling the property, the home inspector says the gas pipe lacks a corrosion-proof coating. I told the inspector that galvanized pipe is corrosion proof, but he disagrees. What can you tell me about buried galvanized gas piping?

Hank

DEAR HANK: Hot tub systems are often installed by homeowners, rather than by professional contractors or technicians. As a result, the gas piping is frequently installed in violation of plumbing and mechanical codes. The most common problem in this regard involves buried steel gas lines.

The galvanized coating on steel piping is considered to be rust resistant, not rust proof. This is why older homes with galvanized water lines often need to be repiped. After 30 years of continuous contact with moisture, galvanized steel can become severely rusted, often resulting in leakage. Buried galvanized pipe is acceptable when used as a water conduit, because leaking water is problematic but not dangerous. Where combustible gas is involved, buried galvanized steel is unacceptable, because leakage can pose an obvious and extreme hazard.

Buried steel gas lines should be plastic coated, wrapped with a special corrosionproof tape, or it should be an approved-type plastic. My advice is to have your gas piping to your spa reviewed by a licensed plumber and either wrapped or replaced in accordance with the plumber's recommendation.