HomeMy WebLinkAboutCORRESPONDENCE - PURCHASE ORDER - 9166427FC Golden Meadows- Lake Aeration 2016
Aquatics Associates, Inc.- Prepared 9/19/16
AQUATICS ASSOCIATES, INC.
3013 E. Mulberry St.
Fort Collins, CO 80524
970.493.2626 fax 970.493.3636
DATE: September 19, 2016
TO: Matt Pflieger
City of Fort Collins - Parks
Mpflieger@fcgov.com
FROM: Tami L. Schneck
Sr. Aquatic Biologist
tami@aquaticsassociates.com
SUBJECT: Scope of Work and Estimated Costs
FC Golden Meadows Pond – Aeration Equipment
AERATION EQUIPMENT
Costs are provided below for an aeration system for the 3.3 acre pond at the City of Fort Collins, Golden
Meadows Park. A brief scope description of work and associated costs are provided below.
A subsurface aeration system was designed for the Golden Meadows Pond based on surface area, water
depth, and bottom configuration. Aeration equipment will be installed to oxygenate and circulate lake
waters, to oxidize suspended and bottom organic matter, and to ensure sufficiently high dissolved oxygen
levels throughout the water column to improve and maintain the pond’s overall water quality.
One aeration system consisting of one compressor and three diffusers will be adequate for the 3.3-acre
pond. Air will be supplied to the diffusers by one Gast 1/2-hp rocking piston compressor (230-v, 1-ph)
capable of delivering ~4.3-4.5 cfm of air to the diffusers (minimum) against the discharge pressure of 10-
12 psi and a maximum pressure of 30 psi. Note that this compressor is the same as installed by Aquatics
Associates, Inc. (AAI) at Fossil Creek Park in 2015, which will allow for consistency in your maintenance
(Steve Wixson knows how to rebuild this compressor).
This system will mix the pond water volume every 8-12 hours (2-3 turnovers per day) using three
Duraplate flexible membrane type diffusers (also same as installed at Fossil Creek Park). The bubble
size will not be greater than 1/8” diameter to provide maximum oxygen transfer. This aeration system is a
low-intensity type that creates non-turbulent mixing. The three diffusers will be strategically positioned in
the pond in the deepest areas (maximum depth contours 6.0’) to sufficiently oxygenate and circulate the
entire water column. Diffusers will be appropriately spaced to provide the best water circulation and
prevent stagnation. Compressor run-times will be controlled by 24-hour programmable time clocks to
allow for 24/7 or intermittent run-times. The compressor should operate at least 12-16 hours per day and
at intervals of 4-6 hours on a year-round basis.
The compressor, air control valves, and fittings will be mounted inside the existing irrigation pump house
in the back left corner. The compressor will be mounted on a steel shelf. Three air lines will be installed
off the compressor, which will be housed inside one PVC conduit sleeve (4-6” sleeve) through the wall of
the pump house to the pond shore. Flexible self weighted ¾” air hose (0.64 lbs./ft.) will extend from the
shore to the diffusers, while CTS direct bury pipe will be used inside the PVC sleeve.
Aquatics Associates, Inc. (AAI) will supply all aeration equipment and installation. Any electrical work
required (i.e., receptacles and wiring of compressors, timers, lighting) will be provided by client and
coordinated by Tami Schneck. Electrical requirements for this compressor at 230-v, 1-phase is 3-5 amps
with minimal load for the time clock (230-v). Electrical service to this equipment should be fed by one 20
amp circuit.
In addition to the electrical, the client will be responsible for 1) boring a hole in the pump house wall, 2) the
PVC sleeve, 3) trenching (2’ minimum depth) from the pump house to the pond shore, and 4) clearing the
cattails in the area where the air lines enter the pond.
FC Golden Meadows- Lake Aeration 2016
Aquatics Associates, Inc.- Prepared 9/19/16
AAI will warrantee aeration equipment for two years against defects in workmanship or materials. There is
a one-year manufacturers warranty on the compressor and time clocks, and a five-year warranty on the
diffusers (FOB manufacturer).
SCHEDULE
The aeration system can be installed in October, with the installation dependent on completion of tasks
outlined above that are the client’s responsibility. Work can be scheduled as soon as authorized and a
Purchase Order is received. I will coordinate this work with Matt Pflieger.
A certificate of insurance for the current year can be provided via email (to John Stephen?). Let me know
if you have any questions or need additional information.
AERATION SYSTEM COSTS
1. Aeration Equipment
Cost
(in existing pump house)
1- 1/2 hp rocking piston compressor (115/230-v, 1-ph, 30 psi max.)
3- Duraplate flexible membrane diffusers w/ PVC ck valve
compressor fittings (pressure relief valve, liquid filled pressure gage,
3-way air assembly, Vicont 400 oF brass check valve, ½” 300 psi high
pressure air hose, copper & bass fittings)
1,100-1,200’ ¾” self-weighted air hose, 250’ 1” CTS feeder lines,
compressor installation fittings & hardware pkg., misc. materials
1- Intermatic 24-hour time clock and additional trippers (230-v)
Steel shelf for compressors (~72-84”x20”x30-32”- materials, fabrication,
finishing, mounting hardware)
Subtotal- Equipment $5,415 - $6,305
Installation- *
Assemble & install all equipment (steel shelve, weighted
& CTS air lines, 3 diffusers, 1 compressor & fittings;
coordinate all work (electrical, sleeves, pump house specs);
equipment start-up
Subtotal- Installation $1,400-1,680
_____________
Estimated Cost- Aeration Equipment $6,815 - $7,985
TOTAL COST Not-To-Exceed $7,985
• FC Parks will be responsible for trenching and installing PVC sleeves from pump house location to pond
shore, clearing cattails at pond edge, and electrical service to the equipment.