Greenfield reviews proposed sewer-rate hikes as city pursues new wastewater plant

Greenfield City held a special City Council workshop on Sept. 30 to review a draft sewer rate study and discuss financing for a replacement wastewater treatment plant after officials said the town’s existing 1978 plant is failing and at permitted capacity.

City staff told residents the city needs roughly $111.3 million to build a new plant and presented three funding scenarios: a “best case” that assumes a $75 million state grant plus a low-interest loan and bonds; a “worst case” with no grant that relies on a larger mix of low- and market-rate borrowing; and an intermediate outcome. Staff said the rate study models the worst-case scenario for next year and shows an overall 65% average increase in sewer charges in the first year, followed by smaller annual increases under the preferred option or much larger increases in the alternate scenario.

Why it matters: officials said the current plant’s age and capacity shortfall are producing noncompliant effluent and increasing operational failures as inflows grow. The council previously passed a building moratorium intended to limit new development while the wastewater issue is resolved, but staff said that moratorium is not in effect until the state’s Housing and Community Development (HCD) office signs off.

Staff presentation and funding scenarios City staff described the plant as roughly 47 years old, beyond its 30–40 year useful life, and currently at its permitted daily inflow limit (about 1.2 million gallons per day). Staff said the city completed a wastewater master plan in 2021 recommending options; Greenfield has proposed a membrane bioreactor (MBR) system, which staff said has a smaller footprint, produces higher-quality effluent, is modular for staged expansion, and can produce recycled water. Staff also discussed an alternative — building a long pipeline to convey wastewater to Soledad — and said that option would involve substantial unknown costs, environmental review, and political and operational risks.

Staff presented two numbered rate scenarios used in the rate study documents and an open “scenario x.” The study’s figures shown at the workshop include: - Estimated total project need: $111,300,000. - Scenario 1 (preferred/best case): $75,000,000 in state grants + ~$31,000,000…