The following message was sent to all gardeners using the organic garden site on Old Jacksonville Road:
Dear Organic Gardeners:
In an ongoing effort to brief everyone, we are providing the group with the findings with respect to the initial soil analytical results from the organic gardens. As you may know, we hired Louis Berger to perform professional environmental services at the organic gardens property located at 35 Old Jacksonville Road in Montville Township. A summary of Louis Berger’s preliminary findings are as follows:
Lead, arsenic, and DDT (and its breakdown products DDD and DDE) were detected in each of the 7 shallow soil samples collected, but ALL at concentrations below the NJDEP’s Residential Direct Contact Soil Remediation Standards (RDCSRS). Dieldrin was detected in one sample, also below the NJDEP’s RDCSRS. This is great news, in that from DEP’s perspective the town does not have a “contaminated site” on its hands, which means there are no regulatory obligations for further investigation or remediation.
The DRAFT laboratory results of the preliminary findings are attached.
Upon further evaluation by Louis Berger of the shallow soil results, they determined some contingency analyses may be beneficial. Specifically, the concentration of dieldrin at one location was above NJDEP’s Default Impact to Groundwater soil screening level. They have activated the deeper sample from this location, to see if they can achieve vertical delineation of this contaminant. They have also activated a contingent analysis of the shallow sample which will hopefully demonstrate that dieldrin is not leaching out of the soil and impacting the groundwater. These data are due on September 2, 2015. In the interim, they are actively fleshing out their interpretation of the lead, arsenic, DDT, and breakdown product concentrations detected in the shallow soil.
We would like to provide you with information contained in an email from a Louis Berger representative on August 27, 2015:
- With respect to the organic designation, what we learned is that previous application of pesticides does not preclude a farm from being certified organic (not that we’re going down the certification route, simply as a thought exercise…). Excluded compounds are not to have been applied in the last 36 months, and tissue samples from crops are collected during inspection. The organic designation has more to do with how the garden is currently operated than how it was in the past.
Our investigation was developed in accordance with the procedures outlined in the NJDEP’s Findings and Recommendations for the Remediation of Historic Pesticide Contamination (March 1999) to evaluate for the need to pursue site remediation. What we found is that lead, arsenic, DDT, and its breakdown products are found at generally consistent concentrations across the field, but all below the states Residential Direct Contact Soil Remediation Standards (RDCSRS). Additionally, dieldrin was detected in one sample, also below the NJDEP’s RDCSRS but above the NJDEP’s Default Impact to Groundwater Soil Screening Level.
- The Residential Soil Remediation Standards were not developed with consideration for consumption of produce grown in the soil. They are risk-based standards with consideration for other exposure pathways (soil ingestion or direct dermal exposure). Connecticut has come up with some guidelines for lead, dieldrin, and DDT for vegetable gardening. The samples collected from within the garden fall below these criteria, however three of the four samples from outside of the current garden area meet or exceed the Garden Soil Target Level for DDT of 0.2 mg/kg with concentrations of 0.22 mg/kg, 0.23 mg/kg, and 0.45 mg/kg.
Several California studies have quantified concentrations in soil of DDT, DDD, and DDE (as a sum) which are acceptable for the consumption of homegrown vegetables based on different levels of risk determined to be acceptable. These concentrations range from 0.34 mg/kg to 3.4 mg/kg. We detected DDT, DDD, and DDE (combined) at concentrations ranging from 0.26 mg/kg to 0.65 mg/kg in the current garden area, and 0.32 mg/kg to 1.15 mg/kg outside of the current garden area.
- One important note: While the Connecticut Garden Soil Target Levels and the California risk-based remediation levels are useful as a frame of reference, care should be taken when comparing them to our data. The current investigation was not designed with enough samples to provide the statistical power necessary to say with confidence that all soil within the current garden area is in fact below the Connecticut guideline of 0.2 mg/kg for DDT.
An available option would be to conduct a risk assessment, to help guide the Township in its decision with regards to the amount of risk it is willing to accept, including a comparison to the risks involved with alternative produce sources, etc. Additional soil samples (probably 15 to 20) would be required to further characterize the current garden area to provide the requisite statistical power for such a comparison.
Based on the preliminary findings, the Township is undertaking the following actions: (1) another round of groundwater sampling, and (2) additional shallow soil samples throughout the garden area from 7 samples to 22 samples to ensure statistical probability for your safety. We expect the results from both the groundwater sampling and additional shallow soil testing on either Wednesday, September 2, 2015 or Thursday, September 3, 2015. We anticipate making a decision on reopening the organic gardens by Thursday, September 3, 2015 based on the additional soil sampling.
Thank you for your patience.
Township of Montville
Draft Test Results