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HomeMy WebLinkAbout2007-05-21 Ordinance 4951'j ORDINANCE NO. 4951 ORDINANCE OF THE COUNCIL OF THE CITY OF PALO ALTO APPROVING AND ADOPTING PLANS FOR IMPROVEMENTS TO ELEANOR PARDEE PARK The Council of the City of Palo Alto does ORDAIN as follows: SECTION 1. Findings. The City Council finds and declares that: (a) Article VIII of the Charter of the City of Palo Alto and Section 22.08.005 of the Palo Alto Municipal Code require that, before any substantial building, construction, reconstruction or development is commenced or approved, upon or with respect to any land held . by the City for park purposes, the Council shall first cause to be prepared and by ordinance approve and adopt a plan therefor. (b) Eleanor Pardee Park is dedicated to park purposes. (c) The City intends to authorize construction of certain improvement projects within Eleanor Pardee Park as shown on the Eleanor Pardee Park Well Site Map, Eleanor Pardee Park Well Site Conceptual Well Facility Structure, Conceptual Profile of a Below-Grade Well Facility, and Eleanor Pardee Park New Well Construction Plan (collectively "Plans") attached as Exhibits "A-I", "A-2", "A-3" and "A-4" including, without limitation, the following: 070531 syn 6050094 (1) Construction of a new well in the northwest area of the park. (2) Construction of an access hatch and vent structure that extends through the existing ground surface to the below grade well house structure. (3) Reconfiguration of the existing ground surface surrounding the access hatch such that the top of the hatch will be flush with the surrounding ground surface. (4) Clearing of vegetation and trimming of existing trees in accordance with City policies and as necessary to provide equipment access for construction. (5) Removal of an existing Modesto Ash tree that is in poor condition and presents a safety hazard. (6) Regrading of the existing ground surface surrounding the access hatch such that the ground slopes gently to the existing grade. 1 (7) Construction of below-grade well facilities including the well housing, a production well, chloramines system components, architectural, landscaping and soundproofing treatments, and lighting. (8) Connection to the existing distribution and storm water systems, or both, if feasible, via extension of an underground pipe from the well to the public right-of-way beneath the existing sidewalk. (d) The improvements at Eleanor Pardee Park will be located in the northwest area of the park away from the demonstration gardens. ( e) Areas disturbed by construction would be restored to conditions and uses similar to those prior to construction, with the exception of the above ground structures. (f) The project improvements will avoid protected trees and other sensitive resources to the extent possible. (g) The new well facility will be designed such to mlmmlze its impact on recreational uses and the access hatch and vent will be designed to incorporate a feature the compliments existing park uses. (h) The projects described above and as more specifically described on the Plans attached hereto as Exhibits "A-l ", "A-2", "A-3" and "A-4" are consistent with park and conservation purposes. (i) The Council desires to approve the projects described above and as more specifically described on the Plans attached hereto as Exhibits "A-l ", "A-2", "A-3", and "A-4". SECTION 2. The Council hereby approves the Plan for replacement and construction of improvements in Eleanor Pardee Park and hereby adopts the Plans attached hereto as Exhibits "A-l ", "A-2", "A-3", and "A-4" as part of the official plan for the construction of improvements in Eleanor Pardee Park. SECTION 3. The Council finds that the projects to construct new facilities at Eleanor Pardee Park are subject to review under the California Environmental Quality Act (CEQA) A Draft Environmental Impact Report for this project was prepared and circulated on November 8, 2006, and a Final Environmental Impact Report for this project was prepared and circulated on February 8, 2007. II II II II 2 070531 syn 6050094 SECTION 4. This ordinance shall be effective on the thirty-first day after the date of its adoption. INTRODUCED: March 05, 2007 PASSED: May 21, 2007 AYES: BARTON, BEECHAM, DREKMEIER, KISHIMOTO, MORTON, MOSSAR NOES: ABSENT: ABSTENTIONS: CORDELL, KLEIN, KLEINBERG APPROVED AS TO FORM: 3 070531 syn 6050094 N A pa207f7 -6542.ai Exhibit A·1 ELEANOR PARDEE PARK WELL SITE CITY OF PALO ALTO NOTES: Figure provides a conceptual simulation of the spatial requirements of the proposed below-grade facility and may be shifted on the site to avoid trees and other sensitive resources. (2) The site would be landscaped to blend in with the surrounding environs and would be developed through a public process including review from the ARB. (3) Site regrading activities would be conducted such that the access hatch rim would be above the flood plain to prevent flood waters from entering the facility. It is anticipated that the ground surface elevation would be raised approximately 2 feet at the access hatch and gradually sloped to existing grade at the edges of the site. pa207f8.8542.ai Exhibit A-2 ELEANOR PARDEE PARK WELL SITE CONCEPtUAL WELL FACILITY STRUCTURE CITY OF PALO ALTO Proposed Above Ground Access Hatch with ventilation (approximately 7 feet x 7 feet) pa20719-S542.ai Site Regrading to Raise Elevation (approximately 2 feet) Exhibit A-3 CONCEPTUAL PROFILE OF A BELOW GRADE WELL FACILITY CITY OF PALO ALTO Exhibit A-4 ELEANOR PARDEE PARK NEW WELL CONSTRUCTION PLAN The proposed Emergency Water Supply and Storage Project (Project) is intended to correct the deficiency in the City's emergency water supply, when compared to the standards recommended by the Department of Health Services (DHS). Impleme~tation of the proposed project includes the construction of a new well at Eleanor Pardee Park. The proposed project design is preliminary and the final project facility design would incorporate input from the public (including property owner and neighbors) received throughout the project planning and environmental review process. The final project design would be subject to review by the City of Palo Alto Architectural Review Board to ensure that project design is consistent with that of the surrounding community. Eleanor Pardee Park Well Introduction Eleanor Pardee Park, located on Center Drive, consists of demonstration gardens surrounded by areas of open space, the September 11 Memorial Gardens, playgrounds and picnic facilities. Eleanor Pardee Park is a 9.6-acre neighborhood park surrounded by single family residences. The proposed well would be located below-grade in the northeast area of the park, away from the existing demonstration gardens. Exhibit A-I identifies the potential development area. Under the proposed project, a new well would be constructed at Eleanor Pardee Park to provide for emergency water supply as one component of the City's Emergency Water Supply and Storage Project. Proposed Well Construction Activities New Well Construction The construction area required for the proposed well site is approximately 100 feet by 100 feet. The project siting would avoid areas with identified sensitive resources to the extent possible. The well site would accommodate the proposed structure (well house containing the pump, valves and piping, electrical equipment), pipeline connections and access, and staging areas required during construction activities. Construction activities include: Site Grading -Well construction activities would require initial site clearing and grading of approximately 10,000 square feet (100' x 100'). The ground surface elevation would be graded such that the top of the access hatch for the below grade well structure above the 100 year flood elevation. In addition the existing ground 1 070227 syn 6050103 surface would be regraded such that the ground slopes gently to the existing grade. This grading feature is consistent with other features already in existence at the park. Tree Removal -An existing Modesto Ash, that is in poor condition, would be removed as it presents a safety hazard according to the City arborist (Dave Dockter). Drilling -The production well borehole (approximately 28 inches) would be drilled using rotary drilling methods, followed by well construction, well development, and pump testing. The 24-hour well drilling would require portable flood lighting for night time construction activities. Installation -Following well drilling, the well casing and well screen would be installed. A sorted gravel envelope would be placed around the screen to prevent sediment from entering with the water during pumping operations. A conductor casing would be installed to a depth of around 100 feet below ground surface, to provide a concrete seal, in accordance with DRS requirements for potable water wells. Pump Testing -Following the installation of the well, a pumping test would be conducted. The test would consist of a step test lasting 8-hours, followed by a 24-hour constant rate test. The step test would be conducted to establish the performance of the well (e.g. production capacity) and to provide the required information to design the pump station facilities. A 24-hour constant rate test would be performed to develop the well and to establish the production capacity. Well Facilities and Connections -Upon establishment of a proposed well, the engineer would complete design of the well facilities including sizing the pumps, designing the well enclosure, and connection to the distribution and storm drain systems. Well House -For Eleanor Pardee Park, a below ground structure, with above grade features of less than 50 square feet, is proposed. The foundation, walls, and roof deck would be constructed of poured in place concrete. The structure would house the production well (including valves and piping), pumping facilities (including pump and motor), electricaV instrumentation as well as the chloramine system components. Construction activities for the below ground structure include excavation and shoring for the below grade features, construction of poured in place elements (including forming, reinforcing, concrete placement and curing), and construction of above ground elements including the access hatch and vent structure. The below ground facilities at Eleanor Pardee Park would be approximately 58 feet by 42 feet in plan, with above grade features of less than 50 square feet in plan. The above grade features, including at grade access hatches and ventilation, would be designed to blend in to the park setting and preserve public access to the parklands (Exhibit A-2). Exhibit A-3 shows a conceptual cross section of the proposed well facility. Chloramine Facility -System components include: prefabricated storage tanks, ammonia and chlorine gas detection features, pressure relief valves with a scrubber tank to prevent discharge of ammonia and chlorine gasses, metering pumps, secondary 2 070227 syn 6050103 containment to prevent any leaks (e.g. concrete containment berms), instrumentation, and controls. Connection to Distribution System and Storm water System. -New 12 inch piping would be installed below ground from the new groundwater well to the existing distribution system pipes. Another pipeline would be constructed connecting the new well to the existing storm drain system. Where possible, the pipeline would be constructed in the same trench as the distribution system piping. It is anticipated that 500 to 2,000 feet of pipe would be installed. Lighting -Lighting at site would be dependent on the security requirements, and public input. If external lighting is required, motion sensor lighting would be installed. Site Restoration -Following completion of well construction activities, construction work areas and staging areas would be regraded, contoured, and returned to conditions and uses similar to conditions prior to construction activities, with the exception of above ground structures (Le .• access hatch) or as desired by the local community. Bare ground would be seeded with native plant species or plantings. Power • Power would primarily be supplied to the well pump station via an electrical line off of an existing transformer. Access • Access to the selected well sites would be via existing roads and it is not anticipated that new access routes would be required. Construction of a new well at Eleanor Pardee Park would not require permanent closure of the park to public use and no loss of parklands would occur, as the ancillary features (approximately 50 square feet) would be blended into the park features. During construction, construction of below ground pipelines could temporarily restrict the use of additional park areas and the demonstration gardens. Construction Schedule Well construction activities (including drilling, construction. and testing activities) would require approximately four to six weeks to complete. Once the well is constructed, the final design of the well equipment and housing would commence, followed by selecting the contractor and construction of the actual well. Overall construction activities would take approximately 10 months to complete. The overall project (including preliminary design, design, and construction) would last up to 47 months. Construction, with the exception of the 24-hour drilling/well testing, would likely occur during weekdays from 8:00 a.m. to 5:00 p.m. Anticipated Results The anticipated benefits of the new well include: .:. The ability to meet the Emergency Water Supply and Storage Project's objective to provide a supplemental water supply during "emergency" conditions through providing 11,000 gallons per minute of reliable well capacity and 2.5 million gallons of water storage for emergency use in Pressure Areas 1,2 and 3. Construction of a well at Eleanor Pardee Park would support this objective by: 3 070227 syn 6050103 ~ Providing for a new high production well (approximately 1,000 gpm). ~ Producing chloraminated water that is compatible with the water in the distribution system. 4 070227 syn 6050103