Hi Mary. Lots of input on ...

Hi Mary.

Lots of input on this. I agree with Mathew Crowhurst. Whatever you choose, the design should include a settling chamber (e.g. septic tank). It will reduce the oils and grease and capture solids. If those get to the filter system it will require more frequent maintenance for the real treatment system. A one day and a half day retention time would be good for the settling chamber. After that, a sand filter or gravel wetland design could work fine. It really does depend on the media available. The finer the media (sand vs. gravel) the more maintenance and larger space. Whatever you use, it should be of fairly uniform size of gravel/sand so it does not plug. Everything should be covered (buried) if mosquitoes are a concern for public health reasons.