An apparatus and method for use in conjunction with grassy swales and sidewalk cross drains to collect and filter or otherwise treat dirty or polluted storm water runoff or other fluid is disclosed. One or more prefilters are installed at one or more inlets to a grassy swale or a sidewalk cross drain,...http://www.google.com.au/patents/US20040173522?utm_source=gb-gplus-sharePatent US20040173522 - Prefilter for water treatment
