If a property owner does not want to participate in the government-sponsored public debris removal program, a property owner can contract with a private contractor to perform the debris removal and conduct the soil sampling. The contractor and property owner must apply for and obtain approval for a private debris removal permit from the County or City (depending on jurisdiction), prior to initiating Phase 2 work.
Property owners can contact the California State Licensing Board to check if a contractor is licensed and insured.  Their telephone number is (800) 321-2752.
The Northern Engineering Contractors Association can provide you a list of contractors that can assist in developing your debris removal plan, including soil assessment and testing.  Their telephone number is (707) 546-5500.
North Coast Builders Exchange also has a list of contractors that can assist in debris removal plans.  Their telephone number is 707-542-9502.