The department shall develop and implement a voluntary consolidated source monitoring program sufficient to accurately characterize the source water quality of the state's drinking water supplies and to maximize the flexibility allowed in the federal safe drinking water act to allow public water systems to be waived from full testing requirements for organic and inorganic chemicals under the federal safe drinking water act. The department shall arrange for the initial sampling and provide for testing and programmatic costs to the extent that the legislature provides funding for this purpose in water system operating permit fees or through specific appropriation of funds from other sources. The department shall assess a fee using its authority under RCW
43.20B.020, sufficient to cover all testing and directly related costs to public water systems that otherwise are not funded. The department shall adjust the amount of the fee based on the size of the public drinking water system. Fees charged by the department for this purpose may not vary by more than a factor of ten. The department shall, to the extent feasible and cost-effective, use the services of local governments, local health departments, and private laboratories to implement the testing program. The department shall consult with the departments of agriculture and ecology for the purpose of exchanging water quality and other information.