The document discusses wastewater pretreatment systems from SeptiTech, including: - Residential and commercial pretreatment systems that use biological trickling filters without chemicals to treat wastewater. - Systems typically include a septic tank, SeptiTech processor, and disposal field. The processor nitrifies and denitrifies wastewater through recirculation. - Testing shows systems reduce BOD, TSS, and nitrogen to meet EPA/NSF standards for various commercial and residential applications.