WAC 246-272B-06200. Sewage characterization

(1) The design engineer shall identify sewage characteristics in terms of the following: (a) CBOD 5 , TSS, O&G, BOD 5 , and fecal coliform bacteria; (b) Other parameters that can impact treatment anywhere in the treatment sequence including, but not limited to, pH, temperature and dissolved oxygen; and (c) Nitrogen and phosphorus, where either parameter is identified as a contaminant of concern. (2) For LOSS treating sewage from nonresidential or commercial sources, the design engineer shall submit: (a) Discharger information to show the sewage is not from an industrial facility; (b) Sewage characterization that identifies any parameters not typically found in residential strength sewage; and (c) Data that demonstrates that effluent quality is or will be equivalent to or better than effluent from a properly sized septic tank treating residential strength sewage.