Castle Rock — The Town Council unanimously approved a resolution on Oct. 21 to amend the town's contract with Corollo Engineers to continue a phased odor evaluation of the Escavera collection system, following months of community complaints.

The resolution authorizes an additional $146,922 for Corollo to proceed with a phase 2 scope of work that will evaluate mixing improvements, additional treatment technologies and potential capital alternatives for the sewer corridor that runs through parts of the Woodlands neighborhood. Staff said the work would continue through March 2026 and may lead to recommendations for capital investments such as redirecting a lift station or relocating odor control facilities away from residences.

Mark Marlow, water operations staff, outlined the history: the sewer corridor was built in 1987; housing nearby was constructed beginning in 2006. Odor complaints resurfaced in recent years despite an earlier air-treatment system. The town retained Corollo in May to perform phase 1 sampling and modeling. Following Corollo's early findings, town crews increased bi-oxide injection rates, performed twice-daily inspections, chemically cleaned and replaced media in the odor facility and sealed manholes. Staff said hydrogen-sulfide readings and complaint counts have dropped since those operational changes.

Brad Patton, a resident and HOA representative, told the council the neighborhood had not experienced this level of relief previously and said: "It's the first summer in the 7 years I've lived here that we've actually been able to use our outdoor facilities without having to worry about the odor." He asked the town to institutionalize monitoring and operational commitments so the problem does not reoccur.

Marlow said the town may ultimately consider capital changes, including rerouting flow to gravity sewer or moving an odor control facility farther from homes. The water commission unanimously recommended council approval; staff also recommended the amendment.

Councilmember Brooks moved to approve the resolution; Councilmember Davis seconded. Roll call vote was unanimous, 7-0.