1. RPA and the DEQ Drive for Lower Detection Limits
Spencer Bohaboy
Policy Development Specialist

2. Introduction How DEQ Develops permits
How DEQ uses QLs in NPDES permits
Timeline of QL development
2015 DEQ Lab revision
Future
Questions

3. How DEQ Develops Permits
Reasonable Potential Analysis
Process to determine if there is a “reasonable potential to cause or contribute to the exceedance of water quality criteria”.
2 simple water quality models
Aquatic Toxicity Criteria
Human Health Criteria
Uses effluent and ambient characterization data to calculated potential impacts at the end of pipe or at the boundary of the mixing zone

4. How DEQ Develops Permits
Lab Work
Lab Work
App. 3 years
Issue Permit
Tier 1 Monitoring
All Tables 1 & 2 parameters
Applicable Table 3 parameters
4 x in 24 months
Identify POCs
“End of pipe RPA” to identify Pollutants of Concern (POCs)
Sampling Plan
Tier 2 Monitoring
Ambient data for POCs
Optional: additional effluent data
Optional: Source Investigation
Run RPA and Calculate WQBEL
Intake Credit
Background Criteria
“Can permittee meet WQBEL?” Y/N
Year 0
Year 2
Year 3
Yes No
Write Permit
Select appropriate limits (lowest)
Special Conditions (if necessary)
Compliance Schedule
Additional Monitoring
Required BMPs or Benchmarks
Document decisions in PER
Select Option
Work with permit writer to select most appropriate implementation option
Now What?
Source Reduction
Engineering
Compliance Schedule
Variance
Standards Change
Year 5
RPA IMD:

5. Permit Development: Various Sample Locations
For each Pollutant of Concern (POC) identified, ambient and more effluent data is required
For some POCs, might also require other forms of data
Intake credit: municipal or ground water supplies
Source identification: raw sewerage from industry or major junctions in collection systems
Influent at headworks
Permittee develops a monitoring plan
Timing is important
Seasonal
Hydraulic retention time

6. How DEQ Uses QL’s in NPDES Permits
Permit development
Characterization of the ambient waters
Characterization of the effluent
Sometimes characterization of influent, source water or points within the sewer collection system
Intake, BLM, misc studies
Compliance
Where Water Quality Effluent Limit (WQBEL) is less than analytic limit, the analytic limit becomes the Compliance Level
For example, if WQBEL = 1.0 ug/l and Quantitation Limit is 5.0 ug/l, then “ND” or “detect” would indicate compliance.
Permit Language: “DEQ has established a minimum Quantitation Limit of 0.05 mg/L for Total Residual Chlorine.  In cases where the monthly average or daily maximum limit for Total Residual Chlorine is lower than the Quantitation Limit, DEQ will use the reported Quantitation Limit as the compliance evaluation level.”

7. Timeline of QL Development
DEQ ~2005, First attempt at establishing QLs
DEQ 2007, Second attempt at establishing QLs
Work group of DEQ and labs (municipal and commercial)
Compared QLs to Water Quality Criteria
Surveyed area laboratories for relative performance levels
Approximate number of criteria below limits was ~40%
DEQ 2011, Updated QLs for Human Health Criteria
Update a few parameters based upon conversations with DEQ and labs
Approximate number of criteria below limits was >50%
EPA 2014, Sufficiently Sensitive Rule (SSR)
Amendments to the Clean Water Act require that permit applicants must use “sufficiently sensitive” analytical test methods when completing an NPDES permit application
Also, the Director (head of the permit-issuing authority) must prescribe that only “sufficiently sensitive” methods be used for analyses of pollutants or pollutant parameters under an NPDES permit
Effective August, 2015
DEQ 2015, Revision to QLs
Implemented October, 2015

8. 2015 DEQ Lab revision DEQ 2015, Revision to QLs
Compared QLs to Water Quality Criteria (WQC)
Focus on QLs that were in the range of 1/1 to ½ of the WQC
DEQ Lab made recommendations of estimated changes to QLs to reflect current practice
Changes proposed for 33 of 165 parameters
Values proposed for an additional 19 parameters without WQC or assigned QLs
Surveyed laboratory community (13 laboratories in Or., Wa., Id. and Nv.) on methods used, QLs they can report and whether recommended QLs were achievable
6+1 laboratories reported
Final recommendations
2 QLs to be raised from the current levels
13 QLs to remain unchanged from current levels
14 QL that are higher than originally proposed
28 QLs to remain as proposed
4 additional QL changes that were not originally proposed (Mercury, Dioxin, Methylmercury, Tributyltin)
Oregon was compliance by October of 2015
Detailed SOP and Report is available

9. Recommended QL Changes

10. Recommended QL Changes

11. Future
Electronic Data Delivery (EDD): Working with DEQ Lab, ACWA and Municipal Labs to develop electronic submission of data.
Keys using CAS# to address chemical synonyms
Data repository at DEQ Lab
Ties directly into RPA spreadsheets for “cut and paste” insertion of data
Increase productivity and less mistakes due to re-entry errors
Sarah Rockwell,
Laboratory Data Coordinator
Biotic Ligand Model
examines the bioavailability of metals in the aquatic environment and the affinity of these metals to accumulate on gill surfaces of organisms
Site specific WQC
~10 parameters: upstream, effluent and downstream
Robust data set: i.e. 24 sampling events in 24 months
This might change how we develop permits
Updates to Analytic Limits
Periodic update of limits depending on changes to WQC or analytic technology
Revisit and review of limits every 5 years (approximately)
E-Reporting Rule
Movement towards electronic delivery of data

12. Questions Spencer Bohaboy Policy Development Specialist 503-229-5415

13. Current Permit Language
Detection and Quantitation Limits
Detection Level (DL) – The DL is defined as the minimum measured concentration of a substance that can be distinguished from method blank results with 99% confidence. The DL is derived using the procedure in 40 CFR Part 136 Appendix B and evaluated for reasonableness relative to method blank concentrations to ensure results reported above the DL are not a result of routine background contamination. The DL is also known as the Method Detection Limit (MDL) or Limit of Detection (LOD).
Quantitation Limits (QLs) – The QL is the minimum level, concentration or quantity of a target analyte that can be reported with a specified degree of confidence. It is the lowest level at which the entire analytical system gives a recognizable signal and acceptable calibration for the analyte. It is normally equivalent to the concentration of the lowest calibration standard adjusted for sample weights, volumes, preparation and cleanup procedures employed. The QL as reported by a laboratory is also sometimes referred to as the Method Reporting Limit (MRL) or Limit of Quantitation (LOQ).

14. Current Permit Language
Implementation
The Laboratory QLs (adjusted for any dilutions) for analyses performed to demonstrate compliance with permit limits or as part of effluent characterization, must be at or below the QLs specified in the permit unless one of the conditions below is met.
The monitoring result shows a detect above the laboratory reported QL.
The monitoring result indicates nondetect at a DL which is less than the QL.
Matrix effects are present that prevent the attainment of QLs, and these matrix effects are demonstrated according to procedures described in EPA’s “Solutions to Analytical Chemistry Problems with Clean Water Act Methods”, March If using alternative methods and taking appropriate steps to eliminate matrix effects does not eliminate the matrix problems, DEQ may authorize re-sampling or allow a higher QL to be reported. In the case of effluent characterization monitoring, DEQ may allow the re-sampling to be done as part of Tier 2 monitoring. Sections B.5? and B.6? contain more information on Tier 1 and Tier 2 monitoring.
See page 41 of EPA’s “Solutions to Analytical Chemistry Problems with Clean Water Act Methods”, March 2007 for why matrix interference needs to be demonstrated, and see page 42 for how to make sure a demonstration.

15. Current Permit Language