1. NORTH TRUNK SEWER REPLACEMENT PROJECT
A City of Santa Rosa Utilities Department CIP Project

2. Four Part Presentation
Project Components
History of the project
Engineering Overview /Answers to Key Questions
Summary of Environmental Considerations

3. Project Components Replacement of a portion of the North Trunk Sewer
Maintenance Access Road
Turnaround
Retaining Wall
Utility Easement
Staging Area

4. History and Need for the Project
The existing sewer is over 40 years old and is exposed within Paulin Creek

5. Key Questions Why use the property on Del Rosa?
How is the tank volume (and size) determined?
How will the tanks directly serve the City?

6. Key Questions
3. How will the tanks directly serve the City? …continued
The City currently has NO Aqueduct Zone Storage.
Reduce Current AQ Zone Storage Deficit by 5.2 MG.
(AQ Zone = MG, Citywide = MG)
These deficits are based on 20.6 MG SCWA storage availability.

7. Site Plan – Proposed Project (Alternative 4.1)

8. Environmental Considerations
The Project was reviewed in accordance with the California Environmental Quality Act (CEQA).
All impacts have been reduced to a less-than-significant level.

9. Environmental Setting

10. Environmental Setting

11. ENVIRONMENTAL IMPACTS
Aesthetics
Biological Resources
Geology & Seismicity
Hazards
Hydrology
Land Use
Noise
Traffic & Circulation

12. Aesthetics
Impacts:
Road and turnaround
Road segment leading up from Chanate
Retaining wall
Other components of the sewer – manholes
Mitigation: soil and seed spread over road; color added to asphalt on road segment; some curves added to the road.

13. Maintenance Access Road Extending up from Chanate Road

14. Retaining Wall

15. Biological Resources
Impacts: removal of 8 trees, 4 of which are heritage trees.
Mitigation Measures: Arborist on-site; hand-digging in the root zone; tree replacement per the Santa Rosa Tree Ordinance.

16. Geology and Seismicity
Impacts:
Substantial grading --trench up to 23 feet deep
Proximity to the Rodgers Creek Fault
Mitigation: Construction during the dry season; best management practices for stock-piling of soils; use of flexible connections to allow for longitudinal displacement.

17. Hazards
Impacts: Beneficial impact removing active sewer from the creek; some hazards related to excavation of deep trenches.
Mitigation Measures: Accidental Spill and Emergency Response Plan in place prior to construction; excavation conducted in accordance with OSHA requirements.

18. Hydrology and Water Quality
Impacts:
Potential for sedimentation to Paulin Creek
Potential for encountering high ground water levels.
Mitigation: Construction during the dry season; placement of silt fencing around staging area and active construction zones.

19. Land Use
Impacts:
Addition of components such as maintenance access road, but does not alter land uses on the site.
Project generally consistent with General Plan policies and creek setback.
Mitigation: New easement would be required for the change in alignment.

20. Placement of the sewer line outside of the creek setback area

21. NOISE
Impacts: Substantial noise during the construction period; Some ground-borne noise and vibration.
Mitigation: Construction hours would be established, and equipment properly out-fitted.

22. Traffic and Circulation
Impact: Traffic during the construction period on narrow roadway.
Mitigation Measure: on-site flagger; neighbors notified of project construction period.

23. Access on to Narrow Roadway

24. Mitigation Monitoring Program
A Mitigation Monitoring Program – ensure implementation of mitigation measures.
A monitor would be part of the construction team to ensure protection of resources on the site.

25. Questions…? Topics covered: Project Components History of the project
Engineering Overview /Answers to Key Questions
Environmental Considerations