Attachment_1_-_Draft_Statement_of_Work_1.pdf

Draft Draft Draft

Statement of Work Cottonwood Drain Field Replacement and Expansion

Part 1: Scope/Background/Objective

1.1 Scope of Work

The contractor shall remove and replace existing drain field media and leach lines.

In addition, contractor shall design new drain field with an additional 2 leach lines by expanding the current drain field’s footprint up to 30 feet west of the current edge of the existing drain field. The contractor will relocate the lift station PV array and move it north and out of the drain field while also installing a new utility vault around the multiport valve and the filter that are currently installed. The contractor will also ensure each new line has a vent and inspection port located on the ends of the lines. The lift station pump will also be replaced with one that pumps at 15 gallons per minute and/or perform in accordance with the design of the new drain field expansion; provide submittal for government acceptance.

Upon completion of work the contractor will provide the park an as-builts of the new drain field.

1.2 Background

Cottonwood Visitor Center is the southernmost visitor center for those entering Joshua Tree from interstate 10 located approx. 20 miles west of Indio California. The current septic system was installed in 1999. Currently the visitor center averages at peak season 7,500 visitors per week during the month of March. Visitation falls off to less than half that during summer months.

As Joshua Tree’s National Park visitation has risen over the last decade, the septic systems have been pushed past capacity. At this location the septic system drain field has been saturated and needs to be replaced while also expanding capacity.

Currently the septic system is made up of 2 septic tanks 4,500 and 3,500 gallons in size along with two cylindrical concrete holding tanks. These tanks are inline and as one fills it spills over into the other holding tank which includes a sump pump. This pump is activated when a float detects the holding tank is full or it can be started manually.

Upon activation the sump pump sends fluid through an above ground filter and into a separate vault which has a 4-way automatic diverter that sends the fluid into one of 4 leach lines. Each time the sump pump is activated the 4 port diverter switches automatically to the next leach line in the series and all fluid gets pumped into that one line. After pumping is complete the float deactivates the sump pump and remains off until the next time the holding tank fills. Upon the next pump activation, the 4-port diverter switches to the next leach line in the series.

Existing leach line diameter is unknown. The current lift station pumps at 15 gallons-per-minute.

The pump is run by a PV array with battery backup located within a modern enclosure.

No maintenance nor components located in the system before the lift station pump require maintenance or modifications. All work in this contract will be conducted from the lift station pump to end of leach lines.

It is believed the existing leach lines are an infiltrator type system with each leg being 90 feet long; Each line has an inspection port and vent on the end of the line.

Currently the comfort station at Cottonwood is closed and will not be reopened until the drain field is fixed. The park has porta john service located in the parking lot for visitors to use. Contractor will not have to worry about providing any temporary services while work performing work.

1.2 Objective

The objective of this contract is to expand the existing drain field to meet current demand. The existing drain field to include media and infiltrator lines need to be replaced and reinstalled with additional capacity. The existing PV array and inverter/battery storage compartment will need to be relocated off the existing drain field to a position 50’ north of its current location. PV array and enclosure will need to be installed on concrete slabs and piers identical to its current location.

The Cottonwood Maintenance Yard is available for equipment and materials storage during project. It is located .40 miles away from jobsite.

Part 2: Contractor Tasks & Supplies

2.1 The contractor will conduct the following:

• Design a new drain field which has 50% more capacity than existing drain field.

• Create and provide as-built drawings for new drain field.

• Ensure proper permitting requirements are met and acquired before work begins.

• Add additional 2 leach lines.

• Remove and relocate photovoltaic array to approx. 50 feet north of the current location and out of the existing and new drain field. Remove all existing concrete slabs and piers currently supporting PV system.

• Install PV array and battery enclosure on a concrete slab and piers echoing how it is currently installed.

• Remove and replace drain field media.

• Install a total of 6 new infiltrator type leach lines with inspection ports and vent tubes on the ends of each line.

• Replace the sump pump utilized in the lift station that has a capacity to pump at 15 gallons-per-minute.

• Install new utility vault which encompasses filter and multi-position valve;

provide submittal for government acceptance.

• Install new multiport valve to accommodate all 6 leach lines and/or propose an alternative to controlling which lines receive waste; provide submittal for government acceptance.

Part 3: Contract End Items

Replacement of drain field media to include expansion to a total of 6 leach lines.

Moving of photovoltaic array and battery backup housing for lift station to 50 feet north of current location, replacement of 4-way valve to one that can handle 6 individual leach lines. Replacement of sump pump in lift station and installation of new utility vault which will house the filter and new valve. Proper permitting of drain field and ensuring all work is done to code is required.

** Government submittals to be provided to Joshua Tree National Park Maintenance Division with seven-day review time for government acceptance; continuous communication and partnership between contractor and park’s Maintenance Division is recommended.