Wednesday, 16 April 2014

Plastic Barrel system to safeguard the ground water!

Used plastic barrels method - low cost and simple option to effectively recharge ground water around a house*.

Rainwater from the roof of a building may be allowed to flow through a “PopUp Filter” to recharge ever dwindling ground water.

PopUp filter will remove floating elements and the silt present in the roof top rainwater.  Relatively cleaner water comes out of the filter and is allowed to flow into groundwater recharge gallery.
The groundwater recharge gallery is created by using used plastic oil/chemical barrels (blue coloured drums sold on the road side for construction activities etc.).

Process: Identify an open space around a building to create barrel system of infiltration gallery. Excavate earth to a depth of 6 ft. from the ground level. The width of excavated pit must be slightly more than the diameter of the plastic used oil barrel (around 1¾ ft. or 21 inches)
Length of the excavated pit must be equal to number of barrels used multiplied by diameter.  For example a four barrels infiltration gallery will have an excavated pit of 21 inch X 4 nos. = 84 inch or 7 ft. (length)
Procure the required number of plastic barrels (capacity about 200 ltr) and cut open one side of all the barrels.
Drill two holes, with diameter slightly more than that of rainwater down pipe (4 or 5 inch as the case may be) at the bottom end of the barrels on opposite sides. Install empty barrels, so prepared, in the pit with their cut open side facing downwards. Align all the barrels in one line with the side holes facing each other.  Insert a pipe of 12 inch length to interconnect two neighbouring barrels.
Guide the roof top rainwater pipe connected to the outlet of the Popup filter to the first barrel.  Connect a similar pipe as overflow to the last barrel and leave the outlet of this pipe to the drain outside the building. Make sure a cap with perforations is fitted to prevent rats or insects from entering the overflow pipe at the drain. Also make sure that the over flow pipe end is at a level above the normal water flow level in the drain. Fill up the excavated pit with soil leaving the barrels and the connecting pipes undisturbed. Once the soil over these barrels stabilizes, activities like gardening, cement flooring, light vehicle parking etc. can be taken up.

Rainwater flowing from the PopUp filter flows into these barrel system of infiltration gallery and recharges groundwater.

Many open wells and bore wells or tube wells have got a new lease of life after adopting the barrel system of infiltration.

* System developed by AR Shivakumar

Note: Barrel system should not be tried in the areas with very low porosity in the soil (black cotton soil), place where the water table is already high and places with hard rocky ground with shallow soil cover.