Date Illicit Report Location of Description Actions to be Results & Date Discharge Initiated by: Discharge: If of Discharge: Taken: Who of Investigation Observed Phone, known – E.g. – What, When Investigation: Resolved or & contact lat/long, stream dumping, and Outcome of Closed: Reported: information, address or wash water How…(what Actions taken and etc. outfall #, suds, oil, etc. should be any necessary nearby done) follow-up (what landmark, etc. was done) It is important to collect as much information as possible at the time of initial observation because of the likelihood that a discharge may be transitory or intermittent. Initial identification of the likely or potential sources of the discharge is also very important. Potential outfall investigation scenarios include: No discharge present, no evidence of previous illicit discharge – Action: record and proceed to next outfall. No discharge present, evidence of previous illicit discharge – Action: schedule for in one month. Discharge present – Action: note apparent quality of discharge, take sample for chemical analysis if necessary and appropriate, begin source tracking phase. Drainage Area and Storm Drain Investigations An illicit discharge investigation is to be conducted if any of the following apply: The overall outfall characterization as determined by the ORI (Appendix A) is determined to be “suspect” or “obvious.” On-site or lab water testing results in values that exceed established thresholds. General thresholds are indicated in Table 4 and Figure 18. Each MS4 may refine these thresholds through local sample analysis as the program evolves. See Figure 19 for an example of thresholds that were derived over time for the City of Baltimore, MD. The Figure 19 flowchart also starts with Ammonia as the main screening indicator, and this is recommended, since Ammonia is a strong all-around indicator, meters are easy to use in the field or lab, and waste disposal is easier than for the detergents/surfactants test. If the outfall is determined to have “potential” illicit discharges based on completion of the ORI, the outfall should be re-visited three additional times during the permit cycle to determine if an intermittent discharge may be present. Ideally, one re-visit will occur on a different day of the week than the original visit and/or at a different time of day. Table 4. Dry weather outfall screening water quality indicators Screening Parameter Potential Source Threshold >0.2 Ammonia Wastewater or Industrial mg/l
Date Illicit Discharge Observed & Reported: Report Initiated by: Phone, contact information, etc. Location of Discharge: If known – lat/long, stream address or outfall #, nearby landmark, etc. Description of Discharge: E.g. – dumping, wash water suds, oil, etc. Actions to be Taken: Who What, When and How…(what should be done) Results & of Investigation: Outcome of Actions taken and any necessary follow-up (what was done) Date Investigation Resolved or Closed: It is important to collect as much information as possible at the time of initial observation because of the likelihood that a discharge may be transitory or intermittent. Initial identification of the likely or potential sources of the discharge is also very important. Potential outfall investigation scenarios include: No discharge present, no evidence of previous illicit discharge – Action: record and proceed to next outfall. No discharge present, evidence of previous illicit discharge – Action: schedule for in one month. Discharge present – Action: note apparent quality of discharge, take sample for chemical analysis if necessary and appropriate, begin source tracking phase. Drainage Area and Storm Drain Investigations An illicit discharge investigation is to be conducted if any of the following apply: The overall outfall characterization as determined by the ORI (Appendix A) is determined to be “suspect” or “obvious.” On-site or lab water testing results in values that exceed established thresholds. General thresholds are indicated in Table 4 and Figure 18. Each MS4 may refine these thresholds through local sample analysis as the program evolves. See Figure 19 for an example of thresholds that were derived over time for the City of Baltimore, MD. The Figure 19 flowchart also starts with Ammonia as the main screening indicator, and this is recommended, since Ammonia is a strong all-around indicator, meters are easy to use in the field or lab, and waste disposal is easier than for the detergents/surfactants test. If the outfall is determined to have “potential” illicit discharges based on completion of the ORI, the outfall should be re-visited three additional times during the permit cycle to determine if an intermittent discharge may be present. Ideally, one re-visit will occur on a different day of the week than the original visit and/or at a different time of day. Table 4. Dry weather outfall screening water quality indicators Screening Parameter Potential Source Threshold Ammonia Wastewater or Industrial >0.2 mg/l
IDDE-Field-Guide_Shenandoah.docx