PSC finds Sister Bay’s 2025 sewer rates not unreasonable, assigns commission costs to Sister Bay

Chair Strand summarized the procedural history and legal standard: the commission does not set municipal sewer rates but may review rate disputes under Wis. Stat. §66.0821(5) when a user files a complaint. Liberty Grove argued the 2022 rate study undercounted revenue from unsewered (hauled waste/septic) customers and that the 2025 rates (ultimately set at a 15% increase for residential accounts and 25% for hauled waste accounts) were therefore unreasonable. Sister Bay responded that it used an alternative simplified method, that the 2025 rates were not based on the 2022 study, and that planned capital needs (including an estimated $15,000,000 sludge-treatment facility) justified the revenue requirement.

"The commission does not regulate sewer rates," Chair Strand emphasized when framing the commission’s limited standard: the burden of proving unreasonableness rests with the complainant. Commissioners discussed proportionality across customer classes, whether hauled waste customers are captive or competitive, and the record’s gaps (for example, internal audit evidence and the effect of a future plant on current allocations). Commissioner Nieto said the record made it difficult to find clear mathematical proof of unreasonable rates; Commissioner Hawkins noted hauled waste customers are not captive and thus market alternatives exist for them.

After deliberation the commissioners agreed to the modified alternative: the commission does not find Sister Bay’s rates, rules, and practices unreasonable or unjustly discriminatory under Wis. Stat. §66.0821(5). The commission also resolved that commission expenses attributable to the proceeding should be billed to the respondent, Sister Bay, consistent with recent precedent. Commissioner Nieto moved the motion; it was seconded and adopted by voice vote with aye recorded by all commissioners present.