Comments regarding the May 23, 2007 Nutrient Criteria Stakeholder's meeting
Ms. Bowman
Some quick impressions:
1. I got confused regarding the impact of the components, %old prairie, flushing rate and dam height. Do you have a spreadsheet for the Prairie lakes, showing the individual components for each lake, e.g. the volume of the Lake of the Ozarks divided by the flow into the Lake gives you the flushing rate?
2. You quickly went through the criteria of water quality goals you searched to base water quality decisions on, e.g. taste and odor or disinfection byproducts. When you get the selection of goals documented may I get a copy, please.
3. How did the handful of lakes that were reporting algal blooms compare to the decision matrix that will lead to placing these lakes on the 303d list?
4. A question for the University: Did you take evaporation into account either in the hydrology or in lake processes that would dictate the concentration of Phosphorus in a lake? I ask a serious question since working on a water balance problem that I had initially discounted the evaporation only to find that it was more significant than I suspected.
Old wisdom: Keep your focus on the goal, not on the process. Pick a process that works most of the time and let the Clean Water Commission tweak the system as necessary. Don’t worry about a 25th percentile or an EPA reference level. The goal is having streams that can be enjoyed by our grandchildren, it will take that long for your work to make a difference (paraphrasing John Schondelmeyer, P.E., 1980). I write this not to discourage you rather to commend you for your commitment to the future.
Frank J Dolan, P. E.
GREDELL Engineering Resources, Inc.
After sleeping on it, I do have some comments/suggestions:
1. Permitting issues need to be more fully addressed. If numerical total phosphorus (TP) criteria are adopted in Water Quality Standards (WQS), they will be used to set permit TP limits for point source discharges. DNR should adopt procedures for development of Site-Specific Criteria using the predictive hydrology approach for lakes that exceed the regional reference value. Otherwise, permit limits will be based on TP criteria that are unattainable in the receiving water due to lake hydrology.
2. I suggest that DNR public notice and formally adopt lake nutrient criteria implementation procedures in a separate document incorporated by reference in the WQS rule. The implementation procedures should spell out the permitting procedures as suggested above. Other states have adopted implementation procedures in their WQS (e.g., Arizona). EPA approval of procedures for development of site-specific lake nutrient criteria should eliminate the need for each site-specific criterion to be individually promulgated by rule.
3. To prevent degradation of plains lakes with existing TP below 20 ug/L, my understanding is that DNR is considering designating such lakes as Outstanding State Resource Waters. This may be appropriate for lakes located on state or federal land, but I don't know if all the low TP lakes fall in that category. An alternative approach could be to adopt subcategories of uses; i.e., tiered aquatic life uses for lakes with corresponding TP criteria.
4. The meaning of "Use Attainability Analysis" (UAA) in the flow chart for evaluation of nutrient impairment of lake water quality and as used in the stakeholder meeting presentation is unclear to me. Under federal regulations at 40 CFR 131.10, UAA is used to remove a designated use. I don't think anyone would consider it appropriate to remove the designated use of protection of aquatic life for lakes that exceed TP criteria. Development of the 303(d) list typically involves determination of whether or not state WQS are attained in the water body, not whether designated uses are attained. If DNR is proposing to add a UAA step to the evaluation process, a state protocol for aquatic life UAA will need to be developed. We do support conducting UAA prior to developing a TMDL.
I commend the technical subcommittee for developing the predictive hydrology approach, a scientific refinement of the reference lake approach advocated by EPA. In my opinion, the predictive hydrology approach provides a way to distinguish "natural" eutrophication from "cultural" eutrophication, an important step in setting nutrient criteria. I hope the above comments are helpful in fitting nutrient criteria development into the existing regulatory framework. Thank you for the opportunity to participate in the stakeholder process.
Dorris Bender
Environmental Compliance Manager
Water Pollution Control Department
City of Independence, MO
Georganne - Thanks for all your hard work on the lake criteria. In
response to your request for comments on the proposal presented at
yesterday's stakeholders meeting I have a couple of suggestions. One
suggestion is to link the 52 ug/l and 20 ug/l lines on the' regression
graph' back to a biological response. My guess is chlorophyll-a would
be the easiest, but it could be any bio response the group agrees upon.
Dan mentioned the 52 ug/l line corresponded with 20-25 ug/l
chlorophyll-a. This could be a starting place for linking the
regression graph back to a biological response and protection of the
aquatic life use. We could do the same for the 20 ug/l line as well.
Second suggestion, have the sub-committee discuss where the lines should
be drawn (i.e. 52 ug/l, 40 ug/l, etc. for the upper line). Also, the
group should address which lake groups will adhere to the '52/20 lines'
and which groups should adhere to the 'regression line'. Dan also
mentioned generating a regression for TN (not sure what variables he had
in mind). Hope we can discuss these issues/suggestions at our next
sub-committee meeting (June 19th) or give me call. Thanks again. Gary
Gary E. Welker, Ph.D.
USEPA Region 7
Environmental Services Division
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