COMPLIANCE INFO - Laserfiche WebLink

Home Browse Search

J , Pesticide Rinse Water Disposal Sites -5- 1. The example designated waste levels were exceeded for at least one pesti- cide at most of the sites investigated. Further testing may be required to determine the specific site factors and to determine if there is a threat to water quality and if remedial measures are necessary. 2. At two sites, some pesticides that were not detected in soil samples from 0-6" were present at low levels in the 18-24" samples. In particular, at site #6 diuron, atrazine, and cyanazine were so detected, and at site #11 dimethoate was so detected. Both diuron and atrazine have been detected in ground water in California. Also, at site# 6 diuron, monuron, methomyl , and 2,4,5 TP were found in a well water sample but were not detected in the waste disposal site soils. These findings indicate that for a few pesti- cides the example attenuation factor of 100 fold utilized in Dr. Marshack's report may be too high and more stringent disposal requirements may be necessary to prevent pesticide movement to ground .water. CONCLUSIONS At the majority of pesticide applicator sites investigated, past pesticide rinse water disposal has not resulted in any apparent significant threat to water quality. However, at some agricultural applicator sites where rinse water was discharged to land, pesticide residues were found at levels exceeding the criteria for hazardous waste ( i . e. , DDT levels greater than 1 ppm) and/or at levels that may require management as a 'designated' waste. At two sites ground water is impacted. Consequently, because some rinse water disposal sites do pose a potential threat to water quality, staff have formed two conclusions: 1. Pesticide rinse water that is 'hazardous ''"or 'designated waste' must not be discharged to land except at sites that comply with Titles 22 and 23 of the CAC. It is the discharger's responsibility to determine if the waste (including exterior rinse water) is 'hazardous' or 'designated waste' . Most applicators have not classified their rinse water. 2. At sites where rinse water disposal has occurred, the site operator and/or owner should be required to determine the levels of pesticide residues and the distribution of any pesticides that pose a •threat to water quality. (Other agencies may have concerns for other portions of the environment. ) With respect to conclusion 1. , the following observations are made: A. Due to the expense and difficulty of continually testing rinse water, a 'discharger may elect to manage his waste at the rnost restrictive level that could apply. In California this means managing rinse water as ' hazardous waste' . Most coninercial pesticide applicators contacted by staff .have indicated that the most viable method for managing rinse crater as hazardous appears to be discharge to above-ground tanks and subsequent reuse, treatment, or disposal at a Class I facility (new laws will prohibit such disposal in the near future) . A major problem