Confidential AECOM Environment Draft TMDL for pH Compliance for Barr Lake and Milton Reservoir October 20, 2009 Draft TMDL Review Meeting

2 Confidential AECOM Environment BMW TMDL Table 1.1. Summary of pH data for Barr Lake and Milton Reservoir.

3 Confidential AECOM Environment BMW TMDL Barr averages >0.7 mg/L Milton averages >0.5 mg/L

4 Confidential AECOM Environment BMW TMDL Watershed vs. Datashed

5 Confidential AECOM Environment BMW TMDL Poor relationship of TP to CHL in Barr or Milton; TP is too high to be a factor currently

6 Confidential AECOM Environment BMW TMDL Poor relationship of CHL to pH in Barr or Milton; evident that high CHL yields high pH

7 Confidential AECOM Environment BMW TMDL Relationship of TP to pH in Barr or Milton is minimal at current high TP; shape of decline to expected background is a key question in TMDL development

8 Confidential AECOM Environment BMW TMDL

9 Confidential AECOM Environment BMW TMDL Table 3.1 Apportionment of loads to Barr Lake and Milton Reservoir among sources with the SWAT- WASP model.

10 Confidential AECOM Environment BMW TMDL Table 3.3. Comparison of TP loading estimates for three canals in the Barr-Milton system.

11 Confidential AECOM Environment BMW TMDL Table 3.4. Partitioning of current loading into categories relevant to a TMDL.

12 Confidential AECOM Environment BMW TMDL Table 4.2 Wasteload and load allocations for Barr Lake and Milton Reservoir.

13 Confidential AECOM Environment BMW TMDL Table 4.3 Assessment of variability of flows in three canals delivering loads to Barr Lake and Milton Reservoir.

14 Confidential AECOM Environment BMW TMDL

15 Confidential AECOM Environment BMW TMDL –Public participation –Monitoring Extensive data Intensive plan –Restoration Strategy External vs. Internal Load Wasteload vs. Load Applicable measures  WWTP effluent limits  BMP to control MS4/NPS inputs  Internal load controls

16 Confidential AECOM Environment BMW TMDL Table 8.1 Summary of allowable loads for Barr Lake and Milton Reservoir.

17 Confidential AECOM Environment BMW TMDL Questions, Comments, Discussion