Laguna Treatment Plant Annex Boilers 1 and 2 Replacement (C02330)

The Laguna Treatment Plant process heat system conveys heated water from the combined heat and power engines or plant boilers to the anaerobic digesters. Two gas-fired fire-tube boilers in the existing Annex boiler room provide backup process heat when heating demands are high or the combined heat and power engines are not operating. Both boilers have reached the end of their service lives and do not comply with current Bay Area Air Quality Management District requirements. One boiler has failed emissions testing and is not operational, and the other must be taken out of service by December 31, 2026. The project will replace both boilers within the existing boiler room with boilers of the same capacity and function that are approximately one-half the physical size of the existing boilers. The project also includes replacement of the cold-water pump, hot-water pump, expansion tank, interconnecting piping, Annex building boiler control panel, and roof-penetrating exhaust vent, and installation of a new access door. All work will be confined to the existing building and roof, with no ground disturbance, expansion of use, or increase in heating or operational capacity.