September 2016

Environmental Services conducted a public rulemaking in summer 2016 to create new monitoring access structure rules. A monitoring access structure (MAS) is a privately owned and secure sampling location that allows City staff safe access to collect a representative sample of a business’s discharge to the public sewer system. The federal Clean Water Act requires the City of Portland to regulate pollutant discharges into the public sewer system from certain businesses. Routine sampling of non-domestic discharges from businesses ensures that pollutant concentrations in those discharges do not: harm the public sewer system or the environment; endanger the life and health of the public or workers in the sewer or at the treatment plant; or violate water quality standards.

Portland City Code gives BES authority to require a MAS. BES developed a new set of rules that defines which non-domestic sewer users will be required to install a MAS and provides design and location standards for a MAS. The rules aim to prevent surprises for businesses and eliminate or reduce costs associated with retrofitting unsafe or inaccessible monitoring structures.

No comments were submitted during the 30-day public comment period, and a hearing was not requested. The final administrative rules were adopted on September 16, 2016. The requirements are identical to those proposed during the comment period. The final rules are available on the City Auditor’s website.

A fact sheet is available in the BES library.

For more information or questions about these rules, please contact Angela Henderson by email or at 503-823-7376.