Construction of a Grey Water Cesspit

Most grey water is sent straight to the open gutters that run on each side of the road in Ghana. These gutters then flow into bigger gutters and then into rivers, or into lagoons and then the sea. You can imagine how bad some of these smell. In Ghana urine is also mostly considered grey water along with a lot of industrial run off. Black water is usually run into a sort of septic system, which really is not much of a system at all but more of a glorified holding tank. There is no drain field as most have an outlet to the same gutters we talked about above. Also most do not have any sort of beneficial biological activity and usually fill quickly and need to be pumped out when they over fill and over flow.

(current cesspit covers)
At the beach resort that I work at our kitchen as outgrown its cesspit for the water that comes off the kitchen drains. This is purely grey water as there is no sewage component in it at all. Business has really increased in the last 6 months over the high period of the year and the current cesspit that we have has been overflowing and smelling really bad. Most of this comes from doing the dishes and cleaning seafood and other food to prepare in the sinks. There is a lot of oil and fats that accumulate in the pit and go rancid creating the horrible smell.

We have combated this for a while by having one of the workers clean it out by bucket and pump and shovel after the water is done. Of course we have to reward this person handsomely because it is a pretty gross job so it gets expensive and it is not very sustainable. There is also no good answer as to what to do with the water in that situation because the pit is next to a wall and on the other side of that wall is a gutter used to channel clean rain water from the property down to the beach. So this is not something we would be wanting to add stinky cesspit water too.

My workers just wanted to create another pit and then pump it out when needed but I decided to look into a little further and adjust the plans to hopefully make a lasting solution. So we did go with another pit and we made sure to leave gaps in the stones so as much water as possible would absorb into the surrounding soil. The idea is that the first tank will collect the fats and particles, the second one will then have cleaner water that can seep into the sandy soil.

The major difference that I made to this plan was that after the second tank there is a gravel trench. This is a trench that is dug and course gravel put in and then a 4 inch pvc pipe with holes all over in it is placed.

When the second pit finally fills the cleanest water will be able to run down the pipe and then out of it into the gravel and then into the surrounding sand. The idea is to get the water as clean as possible and then into the ground. It will not flow very well into the ground if it is full of oil and small bits of food.

The last steps are to link the two tanks together with another length of pipe.

Then covers were cast to put over the new tank.

Everything is filled in and in time we will know if it all works.