These should be performed by the state agency, but if they do not respond promptly, then the analyses won't be worth anything. In that case, the samples you collected may need to be analyzed. The state health agency can supply a list of laboratories that can do the analysis. Be sure that the lab tells you the detection level for their method. Documentation of the amount of the damage 10.
County agents can give an estimate of the value of shade trees and ornamentals.
Estimates of past yields and yields of unaffected fields are useful in estimating crop damage. Keep records of visits to doctors, time missed from work, medication, etc. for health-related injuries. Keep track of the costs of determining the damage. Tell us what happened. Please tell us what happened and how well the state agency and EPA responded.