- [Reference dose established by the EPA Office of Pesticide Programs (mg/kg/day) x 70 kg (adult body weight) x Relative Source Contribution (0.10 for inorganic; 0.20 for organic)] / [2 liters/day (avg. lifetime water consumption)];
- Concentration which corresponds to an incremental lifetime cancer risk of 1 x 10-4 to 10 -6 for class A and B carcinogens;
- The ground water quality standard will be specifically identified in each chemical specific SMP. When the proposed ground water quality standard calculated from either 1 or 2 above is less than the Practical Quantitation Limit, the ground water quality standard is the Practical Quatitation Limit.
Response to Complaints
All incidents reported as a result of a fire or spill will be immediately referred to the IDEM Office of Environmental Response for their consideration. Under certain circumstances the Office of Environmental Response (OER) is responsible for coordinating the containment of the source, an assessment of the environmental impact and clean up of the event. Information gathered as the result of an OER investigation will be forwarded to OISC and to the IDEM Office of Water Management, Ground Water Section. The OISC will determine if a violation of the Indiana Pesticide Use and Application Law or the Indiana Pesticide Registration Law has occurred. If it is determined that a violation has occurred OISC will refer to the current enforcement response policy (Appendix H) for guidance in proposing the appropriate enforcement action. The IDEM Office of Water Management, Ground Water Section, will include any sampling information as part of the pesticide in ground water data base information and coordinate with OER to determine if additional water monitoring activities are appropriate.The IDEM and the OISC shall screen all of the complaints they receive concerning the potential of contamination or alleged contamination of ground water with pesticides. Follow up to complaints will be initiated based on the vulnerability of the areas or sites involved, the alleged incidents or activities contributing to the complaint, and the pesticide(s) of concern.
Complaints which occur as a result of alleged improper application, storage, or handling of a pesticide will be forwarded to OISC for consideration. The OISC is responsible for the on-site inspection, sampling and interview process concerning the incident. The OISC is responsible for notifying or attempting to notify by mail the complainant and owner/operator of any sampled well of results of sample analyses completed. The OISC will include the results of sampling information as part of the pesticide in ground water data base information.
If during an investigation by OISC, a sample analysis determines detection of pesticide in ground water, the information gathered will be forwarded to the IDEM Office of Water Management, Ground Water Section, who will include sampling information as part of the pesticide in ground water data base information. The IDEM Office of Water Management, Ground Water Section may refer the case to IDEM OER for consideration of site cleanup; and coordinate with the appropriate IDEM Offices for site cleanup/disposal or oversight of a voluntary remediation effort by the responsible party.
If during an investigation by OISC, a soil sample analysis reveals detection of a pesticide that is determined to be a threat to ground water, but pesticides are not detected in ground water samples, the information gathered may be reported to the property owner and product registrant with information regarding possible remediation options which may be deemed protective of ground water. The necessity to make such notification will be determined upon examination of the characteristics of the specific pesticide(s), the level(s) detected, and the ground water sensitivity or vulnerability of the immediate area. Appropriate remediation may include passive as well as active measures. Passive remediation activities may include development and implementation of best management practices or site plan review and approval by OISC and IDEM.
Complaints which allege contamination of private residential wells, public water supply wells or ground water through label directed use of pesticides shall be forwarded to IDEM Office of Water Management, Ground Water Section for consideration. The IDEM Office of Water Management, Ground Water Section is responsible for the on-site inspection, sampling and interview process to determine the origin of the pesticide contamination. The prioritization of response to complaints is outlined below:
- Is pesticide in ground water confirmed or alleged?
- Has a ground water quality standard or advisory been exceeded?
- Exposure (acute versus chronic) ?
- Type of pesticide (known carcinogen) ?
- Proximity to population center?
- Type of population exposed (children or adult)?
- Known or alleged sources of contamination?
- Distance to source?
- Type and construction methods of well?
- Vulnerability of hydrogeologic environment?
The IDEM Office of Water Management, Ground Water Section is responsible for notifying or attempting to notify by mail the complainant and owner/operator and product registrant of any sample well of the results of sample analysis completed. The IDEM Office of Water Management, Ground Water Section will include the results of sampling information as part of the pesticide in ground water data base information. If the origin of contamination is determined, the IDEM Office of Water Management, Ground Water Section may refer the case to IDEM OER for consideration of the site cleanup, and coordinate with the appropriate IDEM Offices for consideration of site cleanup/disposal or oversight of a voluntary remediation effort by the responsible party.
Response to Detections:
Reports of pesticide detection in ground water or closely hydrologically associated surface water may originate from many sources including governmental agencies, water suppliers, researchers and others. When pesticide or metabolite of concern detections are reported OISC and IDEM Office of Water Management, Ground Water Section will confer and then coordinate efforts to evaluate each such detection to determine the appropriate course of action. It is important to note that not all detection will warrant a response. The response in any area will include only the components that are appropriate, as based on local conditions. OISC will continue to take the lead in the development of any necessary management plans. A technical advisory group to assist OISC and IDEM in evaluating the need for a response and developing recommendations for consideration by the Indiana Pesticide Review Board will be utilized. The technical advisory group is to be appointed by the Review Board and include representation from the product manufacturer for the specific pesticide of concern.
Generally the response to detection of pesticides
will include a series of progressive components, which may include
but not be limited to:
- Conduct data and source evaluations (i.e. confirm detection in ground water or detection in surface water used as drinking water for which the annualized average of quarterly samples exceeds the MCL);
- Compare the level of detection to the standard;
- Notify residents and water users in the area of confirmed detection if a public health risk is determined to be a possibility. Information release should be coordinated with local health jurisdiction;
- Perform vulnerability assessment and define response area;
- Expand monitoring if necessary;
- Seek restricted use classification if necessary, through the Indiana Pesticide Review Board;
- Educate and set standards for training of pesticides users;
- Explore education and management options (i.e. BMP's, Pesticide Management Areas, Prohibition Areas);
- Develop source prevention and remediation plans if necessary;
- Define other response options.
Several of these terms used to describe various response
activities and a description of when and why these activities
may be appropriate are elaborated below.
Data and Source Evaluation
Due to variability in the quality of analytical data when reporting pesticide detection in water, those data not originating from a regulatory program of from a certified laboratory require validation before further action is initiated. Similarly, the sample source, such as a private drinking water well will be investigated to evaluate faulty well construction as a contributing factor to pesticide contamination. Identification of faulty well construction or state of repair will influence response steps. IDNR and the Indiana Well Driller Association will be consulted to assist in this determination. Every reasonable effort will be made to attempt to determine whether the sample source is representative of a point source or non-point source contamination.
Notify Pesticide Registrants
Notifying the appropriate pesticide registrant of a pesticide detection in water is important. First, pesticide registrants may have obligations to EPA to report such detection. Second, registrants may offer both technical and fiscal assistance to address well contamination and registrants will need to be involved in establishment of BMP's or additional product use restrictions that may be necessary to reduce chemical transport.
Perform Vulnerability Assessment and Define Pesticide Management and Prohibition Areas
In the case of contamination of a properly constructed well, this step will encompass a variety of activities specifically targeted at evaluation of the potential for contamination to extend beyond the zone of contribution of the affected well. A determination of significant impact to an aquifer requires characterization of contaminant movement to identify source areas and define the response area. The response area becomes the focus for future preventative actions to prevent further water quality degradation.The geographic boundaries of Pesticide Management and Prohibition Areas will be delineated by utilizing state hydrogeologic setting and ground water vulnerability to pesticide maps, which comply with Indiana Agency Data Collection Standards (Appendix I). The basis for definitions of the hydrogeologic settings consists of the recognition and mapping of glacial terrains, to include two main elements:
- a sequence, or group of related sequences of glacial sediment that reflect deposition in a particular suite of sedimentary environment, and are thus expected to have certain ranges of physical characteristics and spatial relations among internal sediment bodies; and,
- the configuration of the overlying landscape, which is often related directly to the nature of the underlying sequence.
Specifically, then, the geographic boundaries of Pesticide Management Areas and Pesticide Prohibition Areas would be contained to the 1:24,000 scale topographic quadrangle (s) where the hydrogeologic settings of concern are delineated.
Expand Monitoring
Expansion of monitoring will vary according to the factors identified during data and source evaluation. For example, a private well identified with major construction deficiencies or a questionable state of repair may be targeted for resampling after the correction or repair. On the other hand, contamination of a properly constructed well serving a mobile home community would likely result in some increased sampling frequency of the impacted well. In addition, other private wells in the immediate area should be considered for sampling to evaluate the real extent of the contamination.
Pesticide Management and Prohibition Areas
An area may be designated as a Pesticide Management Area based upon the following conditions:(1) measured concentrations in ground water within a full use area (i.e. an area in which full label directed rates, volumes, and application sites occur or are allowed to occur) exceed 50% of the ground water quality standard or interim maximum allowable concentration (the rationale behind the establishment of this level is that these health based levels represent exposure over one's life time and have safety factors included as part of the standard setting process.); or a statistically based trend toward increasing concentrations which over a reasonable period of time would be expected to exceed the standard;
and
(2) the contamination is determined to have resulted from a nonpoint source of a pesticide applied according to label instructions. The Pesticide Management Areas within the state will be defined by hydrogeological factors. Each Pesticide Management Area shall be designated by a rule promulgated by the Indiana Pesticide Review Board.
If in such areas the ground water quality standard
or interim maximum allowable concentration cannot be achieved
after the implementation of a Pesticide Management Area, then
the area may be designated as a Prohibition Area.
The mapped locations
of Pesticide Management Areas and Prohibition Areas will be made
available through the information dissemination committee (Component
#11).
The SMP may require monitoring to determine if the target pesticide is impacting the state's ground water resources. Monitoring data will be considered in determining where Pesticide Management Areas or Prohibition Areas options need to be delineated. Existing validated data from monitoring studies and the pesticide in ground water data base may serve to supplement planning and assessment efforts. Extrapolation of monitoring data to other areas within the state where vulnerability assessments indicate that additional management efforts are necessary may be done on a case by case basis, if the data are reliable and merit such actions.
