1. City of Pacifica 1

2. Why is this Project necessary? 2 City has a history of sanitary sewer overflows (SSOs) – January 2008 storm caused SSOs throughout the City especially the Lower Linda Mar area – In 2011, City was issued a Cease and Desist Order (CDO) by the San Francisco Regional Water Quality Control Board and also entered into a Consent Decree (CD) with Our Children’s Earth Foundation Required the City to update the Collection System Master Plan Required the City to implement a number of measure to reduce SSOs By January 1, 2019, the City should not have insufficient capacity caused SSOs

3. Why is this Project necessary? 3 Collection System Master Plan – Completed in 2011 which identified a cost effective program to reduce SSO – Identified three projects alternatives: 1.Capacity Enhancement Only 2.Collection System Capacity Improvements with Wet Weather Flow Equalization at Linda Mar (EQ Basin) 3.Collection System Capacity Improvements with Comprehensive Sewer Rehabilitation to reduce Inflow and Infiltration (I&I) – Alternative 2 was identified as the most viable alternative 1.Lowest Cost 2.Meets the deadline of the CDO and CD

4. Why is this Project necessary? 4 Wet-Weather Equalization (EQ) Basin Site Feasibility Evaluation – Completed in 2013 and finalized in August 2015 – 2.1 million gallon holding tank – Benefits Provides greater capacity Reduces potential for SSO in the Lower Linda Mar Allows repairs and maintenance on the wastewater force main Creates operational flexibility Reduces peak weather flows to the Calera Creek Water Recycling Plant Complies with the requirements of CDO and CD

5. EQ Basin Design 5 Flows diverted to basin for storage during large storm events Basin contents returned to sewer after events – Pumps and pipes sized to empty basin in 1 day Basin facilities include – Small control building – Full odor control How does it Work?

6. EQ Basin Design 6 Why is it circular? Strongest shape Easiest to construct Lowest Cost Will be designed according to the latest California Building Code Seismic Standards and other pertinent codes and standards

7. EQ Basin Design 7 How does it look underground?

8. EQ Basin Design (Pipelines) 8 Open Cut Installation – Will be used at shallower depths Underground Boring Installation – Will be used at deeper depths – Will be used along the existing public utility easement – There is low probability of private property improvements being damaged or displaced Methods for Pipe Installation Note: In the event any improvements are displaced or damaged during construction, these improvements will be replaced in-kind.

9. How are impacts minimized and controlled 9 VISUAL Site can maintain existing land use Control building is modest in size and can be designed to match surroundings Odor control bed is similar in appearance to a raised planter bed

10. How are impacts minimized and controlled 10 ODOR Basin used during rain events to capture dilute sewage Will be used only maybe 3 to 4 times annually at most Basin emptied and washed quickly and kept dry most of the time Odor control bed eliminates potential basin odors

11. How are impacts minimized and controlled 11 SAFETY and PARKING AVAILABILITY Basin is underground and fully covered Access to basin is via strong, locked hatches Control building is locked and vandal-proofed Site will be graded to maintain parking accessibility and availability

12. How are impacts minimized and controlled 12 DURING CONSTRUCTION Best Management Practices for light, dust, noise, runoff, traffic, etc. Construction method chosen for deep excavation – No vibration – No impact to nearby structures – Proven in high-rise urban construction

13. Five Site Alternatives Previously Presented on March 23, 2015 13 Site Alternative (Old Name) Site Alternative (New Name) A11A A21B B2A C13A D4

14. 2 Pipeline Routings Were Analyzed Pipelines Parallel to And Cross HWY 1 Pipelines Along Local Streets

15. 3 Additional Site Alternatives were evaluated since, totaling 8 Site Alternatives 15 Site Alternative Description 1A Located at the West End of Linda Mar Park-and-Ride 1B Located at the East End of Linda Mar Park-and-Ride 2A Located at the South End of Skate Park Parking Lot (with pipelines that cross and parallel to Hwy 1) 2B Located at the South End of Skate Park Parking Lot (with pipelines that avoid Hwy 1) 2C Located at the Mid Section of Skate Park Parking Lot (with pipelines that avoid Hwy 1) 3A Located at the South End of Crespi Parking Lot (with pipelines that cross and parallel to Hwy 1) 3B Located at the South End of Crespi Parking Lot (with pipelines that avoid Hwy 1) 4 Located at the Linda Mar Pump Station Parking Lot

16. Criteria Used to Evaluate Site Alternatives 16 Long-term impact to Residential and Local Amenities Construction Impact to Residents and Local Amenities Vulnerability to Sea Level Rise and Flooding Cost Schedule Permitting Compatibility with Existing and Planned Landuse Impact on City Revenue Geotechnical Considerations Biological Impact

17. Top Four Site Alternatives Site 1A Site 2B Site 2C Site 3B

18. Top Four Site Alternatives Comparison CriteriaSite 1ASite 2BSite 2CSite 3B Completion Date (Estimate) Jun 2018 Cost, $million$13.0$15.4$14.9$18.3 Caltrans and/or Coastal Commission Permit No Yes Right-of-Way Acquisition from Caltrans YesNo Yes Distance from nearest residential property line 20 ft (North) 30 to 45 ft (South) 80 to 130 ft (South) 290 ft (South) Basin Dimensions (Internal – diameter x depth) 81 ft x 70 ft95 ft x 55 ft 90 ft x 60 ft to 78 ft x 74 ft 100 ft x 52 ft Length of Pipeline350 ft2,220 ft 2,270 ft

19. Top Four Sites Alternatives Advantages and Disadvantages Site AlternativeAdvantagesDisadvantages Site 1A Least expensive ($13.0M) Least sewer pipe to maintain (350 ft) Hydraulically more advantageous because it’s closest to Linda Mar Pump Station Closest to the nearest residential property line (20 ft to the north) Second to the deepest basin (70 ft) Need to purchase property from Caltrans ($1.87M) Will disrupt Samtrans park-and-ride operation during construction Site 2B Second shallowest basin (55 ft) Third least expensive ($15.4M) No need to purchase real estate Additional parking space maybe added as final configuration of the parking lot after construction Second closest to the nearest residential property line (30 ft to 45 ft to the south) Second to the longest pipe to maintain (2,220 ft) The whole parking lot will be closed during construction Site 2C Second to the furthest from the nearest residential property line (80 ft to 135 ft to the south) Second least expensive ($14.9M) No need to purchase real estate Additional parking space maybe added as final configuration of the parking lot after construction Maybe the deepest basin( 60 ft to 74 ft) Second to the longest pipe to maintain (2,220 ft) The whole parking lot will be closed during construction Possible disruption to Skate Park operation Site 3B Furthest from the nearest residential property line (290 ft to the south) Shallowest basin (52 ft) Most expensive (18.3M) Longest pipe to maintain (2,270 ft) Need to purchase property from Caltrans ($2.3M). Upon purchase, City will take ownership of the adjacent wetland approximately 1.15 Acres Southern half of the parking lot will be closed during construction 10 parking stalls will be removed as final configuration of the parking lot after construction Loss of revenue because of the removed parking stall

20. Top Four Site Alternatives Ranking CriteriaSite 1ASite 2BSite 2CSite 3B Completion Date / Degree of City Control Over Schedule 2331 Total Project Cost (Less is Favorable)4231 Distance to Residences (Further is Favorable) 1234 Ease of Basin Maintenance2324 Length of Pipe Line to Maintain4221 Avoidance of Wetlands Maintenance4331 Preservation of Parking and Transportation Amenities 1432 TOTAL1819 14 1213 Note: Each Site Alternative is Given a Score from 1 to 4 ( a score of 4 being the most favorable). The highest score is Most Feasible.

21. Recommended Site Alternative 2C ParameterSite 2C Cost, $million$14.9 Completion Date (Estimate) Jun 2018 Basin Dimensions (Internal – diameter x depth) 90 ft x 60 ft to 78 ft x 74 ft Length of Pipeline2,220 ft Caltrans and Coastal Commission Permit No Right-of-Way Acquisition from Caltrans No Distance from nearest residential property line 80 to 130 ft (South) Staff recommends Site 2C for its lower cost and greater distance from residential area. Final soil investigation will determine the specific location of the basin.

22. Wastewater Department Equalization Basin Site Feasibility City of Pacifica Wastewater Department Equalization Basin Site Feasibility 22 City of Pacifica