The main purpose of a sand filter is to collect stormwater, rid it of pollutants, and then discharge the water into the storm sewer system. First, water is routed from an impervious surface to the ...

Upfront costs are higher with DE filters. But, Wells says, “They make up for it in their ability to provide better filtration.” This option features a large tank filled with sand.

You can separate a mixture of sand and water by passing it through a piece of filter paper. The water is able to pass through the tiny gaps in the paper but the sand particles are too big and are ...