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PROJECT BACKGROUND:
California Water Service (Cal Water) operates a groundwater well site at 825 Carlisle Way in the City of Sunnyvale. The site consist of a chemical building, communication (SCADA) tower, water well and a booster pump. The site previously utilized a 50,000 gallon steal bolted tank, but the water storage tank was removed in 2016.
SCOPE OF WORK:
The project scope consists of replacement of the existing groundwater well, demolition of the existing chemical building, booster pump, electrical control panel and associated water main/s. Once the facilities have been demolished, we will construct a new domestic water well, a new 50,000 gallon steel bolted tank (24’diameter x20’ height), water main, chemical feed equipment and an emergency electrical power generator.
CONSTRUCTION:
The project scope will be completed in 2 phases. The scope of work for the first phase will include the demolition of the site and capping existing well. Once the site has been cleared, the new well will be constructed. The second phase of the project includes the design and development of the support facilities and the overall site.
First Phase (Drilling, construction and testing of new well):
The new well will be constructed via borehole drilling equipment. The drilling activities will have phases where it will be 24 hours a day, 7 day a week continuous operation.
Continuous drilling operation is required to reduce the risk of possible collapse of the borehole on itself and damage to construction equipment. To drill approximately 1,000 feet, it is anticipated that the work will take approximately 2 week to complete the required depth for the well. The drilling contractor equipment includes the drilling rig, several tanks to re-circulate necessary water for the drilling process, back hoe or other construction equipment and a small shelter for their workers.
Second Phase:
The second phase of the construction will consist of the 50,000 gallon steel bolted tank, new water main, chemical shed and an emergency back-up generator. The construction duration is anticipated to take 60 working days. The work shall be done during normal working hours. At this time no evening work is anticipated for this project. The contractor will need various construction equipment for the construction. No mass grading is proposed for the site.
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NOISE:
At this time, it is unknown the noise level that will be generated from the construction of the site and normal operation of the site after construction. California Water Service will comply with all provision of the City’s Municipal Code 19.42.030 for “Noise or sound levels”.
Noise generated during construction will be variable and will likely be in excess of the local noise ordinance. For this reason, Cal Water will hire an acoustical engineer to take necessary measures to not exceed fifty dBA during at night and sixty dBA during the day time at any point on adjacent residential property. California Water Service will take necessary measures to come into full noise compliance.
Electrical Power Generator:
The back-up generator will operate only in a power outage in the area or once a month to test the system. California Water Service will comply with the City’s Municipal Code
19.42.030 by ensuring the testing will be done only during the day. A noise study will be conducted at the conclusion of the project. A noise attenuation system will be installed around the electrical power generator if necessary.
Booster Pumps:
We have not started with the design of the site. Based on other pumps in the area, we maybe utilizing a 100 horse power horizontal pump. The pumps generate 79.5 dBA at three (3) feet from the motor according to the manufacture. California Water Service will comply with the City’s Municipal Code 19.42.030 and ensure the noise from the booster pump does not exceed fifty dBA at the adjacent residential property. A noise study will be conducted at the conclusion of the project. If necessary, a noise attenuation system will be installed around the booster pump.
SITE OPERATION:
Although majority of the operation of this site will be done remotely, Cal Water will access the site daily to conduct daily maintenance. The routine maintenance will not require any heavy equipment. Typical daily maintenance activities will include cleaning of the chemical injector. On an as needed based, Cal Water’s vendor will be delivering necessary chemicals to treat the water prior to being discharged.
HAZARDOUS MATERIALS:
California Water Service plans to store 300 gallons of 12.5% sodium hypochlorite and 100 gallons of 19.5% ammonium hydroxide on site, inside their own separate, respective chemical enclosures. The back-up generator will have fuel stored in a double lined tank under the generator. To meet local and regulatory requirements, Cal Water will store its chemicals, fuel and feed line in a double containment system. This type of system reduces Attachment 7
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the risk of any chemical or fuel leaks. The chemicals are will be used to disinfect the treated water prior to sending into the distribution system. A Hazardous Materials Storage permit will be obtained from Santa Clara County Department of Environmental Health.
WATER DISCHARGE:
During the well drilling process, no water will be discharged from the site.
During the initial well drilling process, the contractor will be adding drilling additives in the water to assist with the drilling as well, stabilizing the well hole and reduce water loss to the surrounding soil. The drilling additive typically consist of bentonite clay and water called “drilling mud”. The drilling additive is approved by both Federal and State for this application. During the drilling process, the cutting is ejected from the drill bit. The cutting will consist of soil, water as well as the drilling mud. The cutting will that will be discharged by the drilling operation will be collected in a mud tank. The tank is typically 200-800 gallons and rectangular in shape with baffles to aid in the separation of the cutting from the drilling mud before it is it is recirculated back into the well. All of the sediments and additives that settles in the settlement tank will be collected and disposed according to Federal, State and local requirements.
Upon completion of the well drilling process and the installation of the well screen, California Water Service will be conducting a 24 hour water production testing. The production testing anticipate discharging approximately 2,000,000 gallons of raw water from the aquifer. The 2,000,000 gallons of raw water will be discharge into the storm drain system.
Upon completion of the site construction, normal operation of the well will require discharge of the initial raw water at start-up per Department of Health. The initial 15 minute of raw water discharge is to flush the system prior to the water going into the tank.
The current well on site already discharges to the existing 15” RCP storm drain line on Carlisle Way. California Water Service will continue to utilize the existing storm drain line and discharging approximately 18,000 gallon of water at the well start-up.
PERMITTING APPROACH
At this time, Cal Water would like to receive approval from the City of Sunnyvale for the project.
The project property is currently zoned R0. For this reason, the project will need to obtain a Conditional Use Permit (CUP) from the City of Sunnyvale. As previously stated, the project will be broken down to 2 phases. The well drilling, construction and testing only will be the first phase of the project. This will help determine the well capacity and water quality. There may be a small time gap between the well installation and the development of the project site. In Attachment 7
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this time gap, California Water Service will submit for necessary permits for the second phase of the project. California Water Service will need to obtain a building permit for the steel bolted tank as well as an electrical permit.
For project consideration by the Site Plan Review Committee, the following document is attached for information purpose. The following documents are:
1. Proposed and existing site plan
2. Site rendering
3. Project description with operational information and construction impact
4. Title report
CEQA
Since a Conditional Use Permit may be necessary for this project, it is assumed that the City will be the CEQA Lead Agency. California Water Service has identified several potential pathways for the CEQA process. The following CEQA exemptions may be applicable:
15301. Existing Facilities consist of minor alteration of existing private structures or facilities involving negligible or no expansion of existing or former use. 15301 (b) Existing facilities of investor owned utilities used to provide public utility services. 15302. Replacement or reconstruction of existing structures and facilities where the new structure will be located on the same site as the structure replaced and will have substantially the same purpose and capacity. 15302 (c) Replacement or reconstruction of existing utility systems and/or facilities involving negligible or no expansion.
This section of the CEQA is applicable to our project because the proposed work on site will not differ to the existing condition. Prior to 2016, the site had a 50,000 gallon steel bolted tank because it was obsolete. California Water Service will be re-installing a new 50,000 gallon steel bolted that meets all current seismic and building standards.
The new well that is being proposed will take place of the existing well on site. The new well is being proposed to be deeper than the current well on site to accommodate future needs of our customers.
The proposed new chemical building as well as the booster pump will replace the existing. At this time, it is not anticipated that the size of the booster pump nor the chemical building or the rate of pump will remain the same. For this reason, the site will not have any modification from the current condition.
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