1. Analette Ochoa, P.E., QSD/P, ToR, WRECO May 22, 2013

2. LID Treatment Case Study- Bransten Road 2 Project Description Conceptual Design with Three Alternatives Design Parameters- MEP vs. C.3 Challenges

3. Project Description 3 Clean Watersheds for a Clean Bay (CW4CB) Industrial Site Location chosen to evaluate potential PCB load reductions 977 Bransten Road – “Hot Spot” Old County Road Industrial Road Bransten Road San Carlos

4. Treatment BMP Concept 4 Both sides Underground treatment/ maximize parking At hot spots Considered Three Treatment Alternatives

5. Treatment BMP Concept – Alternative 1 and 3 5

6. Treatment BMP Concept – Alternative 2 6

7. Treatment BMP Concept 7 Alternative 3 chosen for cost-effectiveness

8. Treatment BMP Concept 8 Watershed Map 15.6 ac

9. 9 $$ Utilities/Potholing Cost effectiveness comparison: $/sq ft of treatment Public meetings: Input from property owners Treatment BMP Concept

10. Design Parameters 10 9 Bioretention Swales in Bulb-outs

11. 11 Design Parameters - MEP Need for parking vs. need for WQ improvements Roadway watershed vs. off-site Reduced width from 8’ to 6’ to avoid gas line conflict Underdrain vs. no underdrains 18” vs. 12” deep bioretention soil Temporary vs. permanent irrigation

12. Special Design Parameters 12 16” deep curb - stability analysis against overturning or sliding Impermeable liner -protection of roadway and utilities Bulb-out Radii - Consideration for trash/sediment accumulation Industrial site - Truck turning radius Irrigation Ordinance - low flow sustainable design Planting - smaller trees due to utility conflicts

13. 13 Challenges Utility conflicts Urban Area Water Main Sewer PG&E Gas Design considerations Impermeable liner Deeper curb on roadway side Concerns with differential settlement

14. Soils 8 borings HSG D Hazardous soils Groundwater 5.5- 7.5 ft 14 Challenges

15. Flat area - Minimum hydraulic head, no drainage system Underdrain vs. no underdrain Planting of trees 15

16. Summary of Bioretention Areas 16 Conceptual: 43 parking spaces and 6,920 sq ft of bioretention area, and 3.57 ac (155,700 sq ft) of treatment Final: 40 parking spaces and 4,540 sq ft of bioretention area, and max 2.61 ac (113,491 sq ft) of treatment

17. Bransten Road - Lessons Learned 17 Coordinate with utility companies early Inform utilities of project goals (compaction) Obtain schedule for review/comment period Pothole Understanding planting goals with utility clearances (overhead/underground) Hold public meetings to get approval from adjacent property owners or companies for parking needs

18. QUESTIONS 18