Concord High dehumidification project nearing completion; refrigerant supply and culvert permit delayed construction schedule

District facilities staff told the Concord Board of Education on Aug. 4 that the Concord High School HVAC dehumidification project was largely installed and that systems would undergo certification testing with Concord Fire before full operation. Facilities staff reported that 19 HVAC units were removed and replaced with 19 dehumidified air units and that the project’s construction and steel work were about 90% complete.

Facilities staff member Mister Cashman said the district expects a substantial completion milestone on Friday, Aug. 15, with power to each new unit and planned system testing with Concord Fire over the following two weeks. Cashman cautioned, however, that the district still awaited delivery of refrigerant identified as “R‑454B.” He said there were positive indicators that the refrigerant would arrive soon but that staff would not declare the system fully operational until it was on site.

Cashman also described a separate but related issue at the campus: a degraded culvert in the area referred to in the discussion as the “trap pond” or “sinkhole.” He said the culvert replacement required multiple rounds of review with DES and that the permitting process delayed material delivery and scheduling, pushing the district to order and store materials with the contractor as a hedge against further delay. “The long and short of it is that delay is causing the actual delivery of materials in the construction to go into the fall of the school year,” Cashman said.

When asked whether delaying the culvert work would limit student access or activities, Cashman said no immediate restrictions were expected and that the temporary plating done previously had held through heavy rains. He said that if an emergency arose staff would take immediate action, but that sequencing the invasive replacement during summer avoided major disruption to bus lanes and pedestrian routes.

Board members asked about construction duration and storage risks. Cashman estimated a three- to three-and-a-half-week construction window for the culvert work and said Merrill Construction would store the materials in its yard. When asked about potential cost increases from storing materials and delaying labor and equipment rentals, Cashman said the primary charge anticipated was storage and that, overall, securing materials was preferable to facing a 4–6 week lead time later.

No formal board vote was required at the Aug. 4 update. Staff recommended moving forward with material procurement and preparing to schedule the culvert replacement during a summer window to minimize disruption.

Background: staff said the HVAC project had significant crane activity over the summer; staff will coordinate with Concord Fire for unit certification and must await refrigerant delivery to activate dehumidification systems fully.