The typical surface system consists of field drains, field ditches, a main collection ditch, and an outlet.
The presence of drain tiles in poorly drained fields and the use of ridges or beds for plants are often beneficial.
To save water and increase yields, Chinese farmers have switched to draining fields several times a year instead of keeping them flooded.
Though the cranberry industry has painted a picture of sun-soaked floating bogs of red berries and farmers in waist-high boots, the reality is a commercial operation that requires massive quantities of water to flood and drain fields of the marsh-grown vine several times throughout the year.
And the dramatic techniques that have allowed big oil companies to improve oil-recovery rates have ended up draining fields all the faster.Harry Longwell, a top manager at ExxonMobil, insists that a new wave of non-OPEC development, from the Caspian to the deep waters of the Gulf of Mexico, is technically feasible.
Also, while mid-Holocene New Guineans did indeed manage water levels for raised bed and drained fields in swamps, they did not use the bunded wet field methods typical for wet taro in eastern Island Melanesia and Polynesia.
In order to explore the influence of site-specific soil properties on nitrogen (N) and phosphorus (P) losses between individual fields and crop sequences, 16 drained fields with clay soils were investigated in a four-year study.
For septic systems and more complex on-site sanitation technologies, manuals and siting guidelines are widely accessible (e.g., U.S. Environmental Protection Agency 2002), and technology choices generally depend on the available land area for drain fields and vertical separation to the water table.
"This is one of those tests where no news is good news," he said, explaining that there should be nothing about the surface above the drain field that would indicate there is a drain field beneath.
Puraflo's advantages over traditional septic systems include a smaller drain field and minimal maintenance, Mr. Hally said.
