July 17, 2013Beth Card Assistant Commissioner, MassDEP 1 Winter Street Boston, MA 02108
Please accept the following as comments on the draft Nutrient Management Framework. We appreciate the opportunity to give you our thoughts on this document as well as the briefing provided to Andrea and I last winter in Worcester. After reviewing these comments you might want to talk with us again in case we’ve got something wrong or misconstrued.
Is there a revised draft document that describes the framework other than the powerpoint presentations we saw? I looked on the website and didn’t see an actual document that would describe the framework. I have reviewed the nutrient management page and the mapping feature showing attainment status. Any guidance document outlining the policy should be made available at some point for formal public comment.
We are comfortable at this point with having implementation guidance, but it should go through a robust public process. Our assumption is that refinement of threshold values based on a robust suite of ecological response variables and tiered aquatic life uses would be forthcoming in the future. We would hope the document reflects this assumption very clearly. The current water quality standards, antidegradation policies, and classifications warrant refinement to ensure we are meeting our goals for the biological part of the Clean Water Act’s “holy trinity” of chemical, physical, and biological integrity.
The idea of using trophic status to characterize thresholds and impacts is reasonable and has the advantage of being generally understood by the knowledgeable public. The assumptions of how the management framework will be implemented are practical and allow for efficient use of state resources (which are admittedly and unfortunately inadequate given budget reductions). The restoration and antidegradation targets set out for each waterbody classification (or trophic status) are critical values in determining the outcomes achieved by this framework. The selection of those targets is exceedingly important as it represents what the public thinks is achievable for our waters.
We understand the framework indicates in some instances (antidegradation targets for both mesotrophic lakes and oligotrophic and mesotrophic rivers) the values will be refined with further data analysis. Our preference would be that any document indicate broadly that all of these values will continue to be refined as a result of both further analysis AND data collection. If further data analysis is needed on the lower end values for oligo- and mesotrophic (1) systems, why not rivers that are mesotrophic (2) which have a seemingly very high value of 50-100 ppb? This seems to skew resources toward practicalities of implementation (meeting lower thresholds) rather than determining a valid ecological condition first and then dealing with implementation later.
CRC fully appreciates that there are instances where effluent limits designed to protect or restore waters are a tough slog for municipalities in terms of cost. We welcome thoughtful discussions about how to implement these constructively, but that conversation should not be packed inside the development of restoration or antidegradation targets more than is based on the existing classification system.
Our comments focus on the restoration targets and are informed by discussions with aquatic biologists, reviews of EPA documents referenced by MassDEP staff, and evaluation of thresholds used elsewhere in New England.
- We understand that while there is a restoration target of 35-100 ppb TP for Class C lakes, which would at the upper end describe a highly enriched and likely highly degraded aquatic community, there are no Class C lakes. The framework might benefit from such a qualifying statement because the way the table reads it is a bit unsettling for those who understand the definition of eutrophy in terms of[TP].
- It is unclear to us how you can create two categories of Class B-warm water fisheries by determining impounded segments have one TP threshold and free flowing another. Isn’t Class B, always Class B in terms of criteria?
- The use of wide ranges of TP values however does beg the question of essentially allowing a waterbody to have a very large allowable amount of ecological change. This is important because your proposed target ranges cross ecological thresholds (meso to eutrophic) in the literature (such as 35 ppb for lakes and 75 ppb for rivers). How will this guidance ensure that a waterbody not cross over a trophic level or see a significant change in biological structure and function? The 75 ppb value presented by Dodds (Water Res., 1998, 32(5): 1455-1462) includes a wide variety of geological areas, including many with p-rich soils which for the most part New England does not have. So even 75 ppb can be presented as a reasonable presumption as a high threshold value for rivers being eutrophic (cf discussion on CT DEEP below).
- We understand that the use of EPA reference values (ecoregion XIV and VIII and the subregions 59 and 58) may provide numbers that are too low given local observations. EPA reference values are 8ppb (P25) for lakes and 31 ppb (P25) or 10 ppb (P25) for rivers in MA depending on where you are. As Dodds (J. N. Am. Benthol. Soc., 2000, 19(1):186–196) noted that “one potential problem with ecoregion approach is that variation over time and space within a small area may be as great as variation among ecoregions.” Accepting then that there is a wide range of nutrient concentrations within a region, and also concurring that you need to figure out an efficient way of implementing nutrient limits, we still do not see from this framework analysis why a range of 50 -100 ppb for free flowing rivers is protective of aquatic life as defined in Class B.
- It is not clear to us that there has been sufficient evaluation of thresholds being used in other adjacent New England states. To what extent has MassDEP used Connecticut, Rhode Island, or New York’s data and analysis on nutrient concentrations and ecological responses? In my discussions with CT DEEP about how they are implementing nutrient limits – which is based on the use of enrichment factors derived from a statistical change point analysis (TITAN) – they have data on ambient [TP] during summer flows of between 10-20 ppb for their lowest enrichment factor (1.9) that protects high quality waters and 50 – 70 ppb for their highest enrichment factor (8.4) that protects their lowest classification. Do you have observations why your threshold ranges are higher than what Connecticut has developed?
- We have heard about observed [TP] of 75-80 ppb elsewhere in New England that produced high diurnal DO swings and pH values greater than 8.5. Have those conditions not been observed in free flowing rivers designated as Class B? Is MassDEP comfortable that allowing for 100 ppb as a restoration target in a free flowing segment will not impact an impounded segment downstream with a restoration target of 25 ppb? If not, how does the nutrient framework handle such a circumstance?
- Is it possible to produce a table of the technology based effluent limits for total phosphorous that shows how a range of restoration targets and dilution ratios produce different effluent limits? I am sure this was done, but I don’t see that type of scenario analysis in the handouts from our presentation.
Given the information we have at hand and our review of the literature and discussions with aquatic biologists (even consideration their application at 7Q10) the threshold values are too high and warrant further evaluation. We think there needs to be a well-articulated plan to advance sufficiently intensive data collection and analysis to produce threshold targets are regionally consistent and ambitious.
Thanks for considering these thoughts and as noted above, we are very happy to listen and learn more about the basis for these numbers. This is an important issue and we are very open to learning more and thinking collaboratively with all stakeholders on this policy.
Xc / Rebecca Weidman