Drainage Problems? Get Well Soon

House Doctor | Gary Dymski

January 22, 2004

Q. The drywell for our washing machine backs up a little, usually after we've had a little bit of rain. I'm assuming the drainage area surrounding the drywell is saturated. We've been in our house for 16 years, and the drywell was in place when we moved in. I intend to replace it in the spring. When I do replace it, are there any other products I can use to build the new drywell other than cesspool blocks or a 55-gallon drum? -- Rich Scofield, Sound Beach

A. Rich, you need to enter the 21st century when it comes to drywells and drainage systems. Using stacking blocks and steel drums for household waste water went out in the 1970s. We're going to help you, but before you do anything, contact the Suffolk County Department of Health Services (631- 852-2100). It offers a free pamphlet, "Home Sewage Disposal Systems in Suffolk County," that covers standards for construction of sewage disposal systems for single-family residences. That way, when you replace the drywell for your washing machine, you'll have current information. While you're at it, you should learn a little more about your septic system. If it was installed in the 1970s, there's a chance it was made of stacking cesspool blocks and could be on its last legs. The Suffolk County Department of Health Services inspects septic systems for new construction only, however, so check with the department, as well as your town or village, about guidelines for installing a drywell.

Many newer septic systems take both "graywater" and "blackwater" discharge. Graywater is the term used for household discharge from washing machines, sinks and dishwashers. Blackwater is household discharge from toilets. However, homes like yours can have separate tanks for each kind of discharge. It's common for one small drywell to handle the discharge from just the washing machine.

Today's drywells are made from either precast concrete or durable plastic.The precast models for graywater discharge generally are round, 4 feet high and 4 feet in diameter, and weigh nearly 1,800 pounds. Jim Harris of Harris Precast in Kings Park sells them for less than $200, excluding delivery. Usually, "delivery" means to the street front of the installation location. So you'll need heavy equipment - a tractor or loader - to move the precast drywell.

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The plastic drywells are sold by a couple of companies, including Cultec (www.cultec.com; 203-775-4416) and Infiltrator Systems (www.infiltrator systems.com; 800-718-2754). Gina Carolan, president of Cultec, says a Model 330 Recharger could be used for graywater discharge and is comparable in capacity to a 4-foot-round precast drywell. The plastic models are much, much lighter - the 330 weighs about 75 pounds - and can be moved by a couple of people. Installation is similar to precast models. Visit the company Web sites for installation and technical information. Cultec drywells are available through Blackman Plumbing Supply.

Here are a couple of other Web sites that provide valuable septic tank information: Septic-Info.com (www.septic-info.com) and the Septic Information Web Site (www.inspect-ny.com/septbook.htm).