North Region Construction - Project 02A2486

Hayfork Culverts

Contract
02A2486 Minor B
02-4J930

Bid Date
02/19/2026

County Route
TRI-003

Description
Culvert spot locations

Bidder Inquiry / Response

Inquiry:

On behalf of our installation partners in California I am requesting an addendum be issued to allow Thermoform PVC Liner as an alternate to the CIPP liners specified.

Thermoform PVC Fold & Form liners are covered under a CALTRANS non-Standard Special Provision and are California Greenbook Listed.

Thermoform is a styrene free, structural lining solution available from 4" - 48" in diameter. There are no VOCs produced before, during or after as a result of our installation process. This creates a safer work environment for construction crews and local residents without harm to the environment.

Unlike CIPP liners, Thermoform is factory manufactured, so the quality is not dependent on a chemical reaction or field curing. With no harmful VOCs, it can be installed year-round regardless of forecast. The liner is manufactured in Birmingham, AL and meets Buy America Build America requirements.

I have attached our Technical Guide for your review. Please contact me if you need additional information.

Response:

“At this time, we are only approved by the North Coast Regional Water Quality Control Board to utilize the Cured-In-Place Pipeliner identified in the contract Special Provisions, therefore we are unable to issue an addendum.”