Dry wells are normally installed where a septic system is the primary method of sewage disposal. By adding a dry well to the sewer system of your home, you will bar grey water, carrying harsh chemicals from entering your septic system. Where as, by permitting these chemicals to enter your septic system would harm the bacteria colony of the septic system.
A dry well will eventually fail, just as septic systems do. This dry well is for a laundry line. In the photo below, look close and you will notice the stones in the soil sticking to the outside of the steel drum. What has occurred here, is the detergents from the laundry this dry well serviced, had solidified in the soil, bonding the stone to the weeping holes in the drum. There fore, not allowing the ground to absorb the grey water from the laundry line.
Step 1: Remove the old drum and surrounding soil and rock. Because the detergents are still in this rock, it would be best to replace the rock. However, you may have a good understanding as to cleaning the rock and reusing it. Your choice. Step 2: Install the new vessel. In the picture below, we used plastic covert pipe. First, drill 1/4″ holes throughout the covert pipe and one large enough to fit around the discharge line, snug.
For our purposes, we installed two vessels. These will be tied together by a 2″ pipe between them. The purpose is to be sure, years after the installation that the dry well will have more life than expected by just having one vessel. The covert pipe is open on the bottom and the top. Therefore, after sitting the bottom of the covert pipe in 6″ of sand, we then added 4″ of 3/4″ crushed stone. Now, when the water hits the bottom of the dry well, the dirt or sand will stay in place. For the top, we will later cover the opening with plastic and cap the top with a concrete cover.
After setting the vessels, you will want to fill around the dry well using 3/4″ crushed stone. The cleaner the better. The crushed stone is in place to prevent dirt from washing into the dry well. So, you will want to have at least a 6″ barrier between the dirt and the wall of the dry well. Once the crushed stone is in, cover the top of the vessels with plastic and set the concrete covers on top. Finish filling in the hole with dirt. You are done.
Our new dry well servicing only a laundry line in operation. Just for fun, we are adding this footage illustrating the piping and the ability to distribute the grey water across the two vessels.
Your dry well will last a very long time, if you use a lint filter and do not use any sort of powdered detergent in your laundry. The detergents dissolve in your washing machine. However, they will settle and re-solidify in your dry well, inhibiting grey water from being absorbed by the soil.