Projects

TANK REPLACEMENT PROGRAM

Tenney Tank Replacement

 Click here for plans: TENNEY TANK PLANS 

Background:    The Inverness Public Utility District (District) has 9 tanks in the system of which six are redwood and three are steel.  There is a total storage capacity of roughly 425,000 gallons that can supply 4 to 6 days of typical system demand for domestic potable use in normal weather conditions.  The problems specific to the redwood tanks are: 1) Seismically unsafe; 2) Leaking; 3) Producing higher chlorine demand loads; and, 4) Vulnerable to fire hazards.  The District’s Capital Improvement Program (presented in November 2016), identified the replacement of the most vulnerable tanks.

The existing Tenney water storage system is critical for the domestic drinking and life safety aspect as a fire water supply for Inverness.  The existing 10,000 and 60,000 gallon redwood tanks are referred to as Tenney Tanks #1 and #3.  (Tenney Tank #2; 10,000 gallon was removed in the 1990’s because of serious deterioration.)  Besides being in poor seismic condition, the redwood tanks exert a high chlorine demand.  The State Water Resources Control Board (SWRCB) inspection of the Tenney Tanks (conducted in June and August, 2017) documented the leaking tanks at the Tenney site.  The District is proposing to eventually replace all redwood tanks in the system.  The District can currently serve all existing and potential water meters.  This project will not be developing new connections.  The two new tanks will be situated in the same location as the prior three tanks.  The storage will increase from 80,000 to 118,000 gallons to help ensure sufficient capacity in future dry weather and drought years.

Project Description:  It is proposed to replace the original three redwood Tenney tanks with two steel tanks designed to current seismic criteria from the American Society of Civil Engineers-7 (ASCE-7) and the American Water Works Association (AWWA).  This requires a volume to allow for “sloshing” of water in the tank during a seismic event. The operating volumes will be 53,000 and 65,000 gallons. The tanks would be positioned to be roughly the same foot print and original water level elevation to maintain system pressure and fire flow capacity.  The two tanks would be installed in a phased approach by the same contractor.  Projected installation date is tentatively set for late 2018.  A new 4’ x 8’ building wooden shed (replacing the existing shed) will be constructed to house the chlorine pump and low wattage radio communications equipment.

Reason for Categorical Exemption: This project is categorically exempt under CEQA Article 19 Categorical Exemption, 15301(b)-Existing Facilities.  This Project undertakes no expansion of use by the District in providing domestic drinking water for the town of Inverness.  The project is also exempt under the California Environmental Quality Act (CEQA) Guidelines Section 15061(b)(3). The activity is covered by the general rule that CEQA applies only to projects, which have the potential for causing a significant effect on the environment. Where it can be seen with certainty that there is no possibility that the activity in question may have a significant effect on the environment the activity is not subject to CEQA.

Stockstill Tank Replacement

Click Here for Bid Documents – Stockstill Tank Replacement IPUD Rev.0

Currently, the Stockstill Tank Replacement project is in construction with completion set for December 2017.

The Work included the removal of two existing 20,000 gallon redwood tanks (referred to as Stockstill Tanks 1 and 2) that are being replaced with a single bolted steel tank.  An auxiliary building 6×6 ft. will be installed.

Background:  The Inverness Public Utility District (District) has 11 tanks in the system of which eight are redwood and three are steel.  There is a total storage capacity of 425,000 gallons that can supply 4 to 6 days of typical system demand for domestic potable use.  The problems specific to the redwood tanks are: 1) Seismically unsafe; 2) Leaking; 3) Producing higher chlorine demand loads; and, 4) Vulnerable to fire hazards.  The District identified in November 2016 the replacement of the most vulnerable tanks.  The two existing 20,000 gallon redwood tanks (referred to as Stockstill Tanks 1 and 2) are identified as the most vulnerable in the District.  They were installed as used tanks in 1955 (age unknown), leak, have deteriorated tank bands and are on a support system that is in poor condition.  Besides being in overall poor condition, the redwood tanks exert a high chlorine demand.  The State Water Resources Control Board (SWRCB) inspection of the Stockstill Tanks (performed in 2011) documented the leaking tanks at the Stockstill site.  The District is proposing to eventually replace all redwood tanks in the system.

Project Description:   The existing Stockstill water storage system is critical for the domestic drinking and life safety aspect as a fire water supply for the Seahaven (Third Valley) neighborhood of Inverness.  It is proposed to replace the two redwood Stockstill tanks with a single steel tank designed to current seismic criteria from the American Society of Civil Engineers-7 (ASCE-7) and the American Water Works Association (AWWA).  This requires a volume to allow for “sloshing” of water in the tank in a seismic event. The tank has been positioned (see story poles) to be roughly the same height by lowering into the ground.  It is proposed to install a single bolted steel tank that is 16.1 feet high by 32.68 feet in diameter.  Projected installation date is mid-to late 2017.  A 6’ x 6’ building wooden structure will be constructed for the chlorine pump and to house equipment for tank and water distribution operations.  Color will be likely be “forest green”.

Environmental Review:   The project is being considered as being categorically exempt under CEQA Article 19 Categorical Exemption, 15301(b)-Existing Facilities.  This Project undertakes no expansion of use by IPUD in providing domestic drinking water for the Seahaven neighborhood of Inverness.  The project is also expected to be exempt under the California Environmental Quality Act (CEQA) Guidelines Section 15061(b)(3). The activity is covered by the general rule that CEQA applies only to projects, which have the potential for causing a significant effect on the environment.