A treatment and irrigation system for relatively large tracts of land used for sports, public gardens, recreation, agricultural crops, or other land uses, wherein the output from a primary or secondary sewage treatment plant is received by a drip, or trickle, irrigation system which is disposed over a relatively large area to be irrigated, immediately under a stratum for receiving the roots of flora to be irrigated and above a layer of very permeable matter which receives the output of the sewage treatment plant. Such output, which is received, in part, through capillary action by flora growing on the upper stratum, drips through the permeable matter layer wherein the output is subjected to an aerobic action due to air in that layer. The permeable layer rests on underlying non-permable base although this also may also be permeable ground. After the output is aerobically treated in the very permeable matter it may be received by ponds or other bodies and is eventually transported by underground water flow between the permeable layer and the base or ground to exit into a river, stream or other water in which it is diffused.
