We do allow alternative systems. The King County Board of Health Code, Title 13 On-Site Sewage code makes provisions for property owners to use of a wide range of alternative OSS systems in Chapter 13.52. Specific standards are included for holding tanks, composting and incinerating toilets, mound systems, aerobic treatment units (ATU), sand filters, gravel-less drainfield systems, proprietary packed bed filter systems, upflow media filter systems and subsurface drip systems (SDS). The code also allows use of any other OSS technologies approved by the State DOH, including systems being tested through product development permits with approval of the health officer. With the wide range of alternative OSS technologies now available MRA property owners have many options to consider if they need to upgrade or replace their OSS.