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READ AND **REMOVE THIS PAGE** BEFORE PLACING

THE SPECIFICATION SECTION IN THE CONTRACT

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[DIVISION 15: MECHANICAL]{.underline}

SECTION 15456 - WATER FILTRATION DEVICES

USE: Furnishing and installing water clarification and filtration
equipment.

**NOTES TO SPECIFIER:**

A. Options within paragraphs are identified by enclosure in brackets;
blank spaces enclosed by brackets \[\_\_\_\_\_\] provide for information
to be inserted, as appropriate, to individual projects.

B. **TO AVOID CONFLICTING REQUIREMENTS AND COSTLY MISTAKES,** the
specifier must edit (delete, substitute or add to the text). The
remaining paragraphs must be renumbered.

C. DELETE FOR FINAL COPY: Notes to the Specifier, located between lines
of asterisks; all \[brackets\], [underlining]{.underline}, **boldface**,
and *italics*, within the paragraphs; and this page. (Open Reveal Codes
\[alt F3\] to do this accurately.)

D. [To Edit "(Footer B)":]{.underline} (Corel 8). **ENTIRE FOOTER SHOULD
BE BOLDED.** Click in the footer and delete the "Project Name (ftr B)"
text and replace it with the **Name of the Project (upper and lower
case)**. Replace date with current MM/YY (WITHOUT BRACKETS).

E. The Guide Specifications are intended to be continuously reviewed and
revised. User's technical comments are appreciated. Also, other related
or similar specification that are written "from scratch" that could
benefit others, or other questions can be sent to NSTC A/E Group, ST
110, or call (303) 987-6868.

**DRAWING DATA REQUIRED:**

**REQUIRED SPEC MODIFICATIONS:**

[GENERAL NOTES]{.underline}

A. Whenever entire articles, paragraphs or subparagraphs are not
applicable, the articles, paragraphs or subparagraphs should be deleted;
when necessary, reletter or renumber articles, paragraphs or
subparagraphs.

B. THIS GUIDE IS NOT INTENDED AS A SUBSTITUTE FOR READING THE ENTIRE
SECTION.

[TECHNICAL NOTES]{.underline}

A. 1.1B: Select or add applicable specification sections. Do not list
specification sections from Division 15.

B. 1.2A: Select applicable specification section.

C. 1.2B: Insert number of copies of the design data required. Normally 5
copies are required. Distribution after review is normally 1 copy to the
COR, 3 copies to the Contractor, and 1 copy to the project file.

D. 1.2C: Insert number of copies of Certificates of Conformance
required. Normally 3 copies are required. Distribution after review is
normally 1 copy to the COR, 1 copy to the Contractor, and 1 copy to the
project file.

E. 4.1 and 4.2: When a \"lump sum\" Contract is used, DELETE the title
PART 4: MEASUREMENT AND PAYMENT, and both articles from this section.
Measurement and payment will be addressed in Part 4 of Section 01010
-Summary of Work.

**REVISIONS OF THIS SECTION:**

CSI format, editorial changes: 12/01

Metric:

Technical Update: 01/91

SECTION 15456

WATER FILTRATION DEVICES

[PART 1: GENERAL]{.underline}

1.1 SUMMARY:

A. Section Includes: Furnishing and installing water clarification and
filtration equipment for pressurized operations.

1.2 SUBMITTALS:

A. General: Submittals shall be according to \[Section 01300 -
Submittals.\] \[and\] \[Section 01365 - Certificates of Conformance.\]

B. Design Data: Submit \[\_\_\_\_\] copies of the design of the proposed
equipment \[and connections to the existing system\] to be used on this
project.

C. Certificates of Conformance: Submit \[\_\_\_\_\] copies of written
certification from the manufacturer that the system as designed and
installed meets the requirements of this specification section.

1.3 MAINTENANCE:

A. Manuals: Submit three complete sets of manuals in plastic covered
3-ring binders to include parts lists and trouble‑shooting procedures.

[PART 2: PRODUCTS]{.underline}

2.1 MATERIALS:

A. General: The water filtration equipment shall be designed by the
manufacturer to work as a total system. The system shall be provided by
the Contractor complete with depth clarifier, depth filter, four
chemical feed tanks and pumps, backflush control, control valves, and
necessary valves and piping to connect the filter system into the water
system and make it operational.

B. Depth Clarifier: Shall function as a contact flocculator to enhance
particle size and as a clarifier by accumulating turbidity on the
surface of the media.

1\. Construction: The clarifier tank shall be a minimum of 36 inches in
diameter and a minimum of 60 inches high, supported on steel legs welded
to the shell. It shall be designed for a working pressure of 100 psi and
tested at 150 psi. The tank shall have a minimum 11 x 15 inch manhole
located in the top and a minimum 4 x 6 inch handhole near the bottom in
the side of the tank. The tank shall have a minimum 6 coat baked‑on
phenolic epoxy lining and an enamel primed or galvanized exterior. The
tank shall have a single point header to distribute raw water and
collect backwash water evenly over the top surface of the bed. The lower
distributor will be hub‑radial design fabricated entirely of schedule 80
PVC. Orifices will discharge laterally to evenly collect treated water
and distribute backwash air and water.

2\. Fill Material: Sufficient underbedding material shall be provided to
cover the lower distributor by a minimum of 4 inches. The material shall
be large enough to remain in place during both the backwash and air
scour cycles. It shall also be small enough to prevent the loss of
clarifier media to service. A bed depth of not less than 40 inches of
clarifier material shall be provided. It shall have a surface area of
not less than 215 square feet per cubic foot of material and shall be
non‑plugging to particles less than 100 micrometers in minimum cross
section.

C. Depth Filter: Shall be designed to work in train with the depth
clarifier and remove suspended solids so that the water quality of the
effluent will be 1 NTU or 90% improvement compared to the influent
turbidity, which may be as high as 100 NTU. The filter shall remove
particles down to 10 micrometers with 90% efficiency.

1\. Construction: The filter tank shall be constructed the same as the
tank for the depth clarifier, to include the water collection and
distribution systems.

2\. Fill Materials: Sufficient underbedding material shall be provided
to cover the lower distributor by a minimum of 4 inches. Two layers of
underbedding material shall be provided. The top layer shall have
sufficient density to remain in place during backwash and small enough
in effective particle size to avoid media loss. The lower layer shall
perform the same as the top layer of underbedding in it. It shall
prevent loss of upper material and remain in place during backwashing.
It must also be larger than the openings in the collector openings. The
filter media shall consist of three layers having a total bed depth of
not less than 32 inches. Individual layers will have the effective
particle size, density, and uniformity coefficient selected to permit
high quality water during the filtering run as well as proper bed
re‑stratification after backwashing.

D. Piping and Plumbing: Piping and valves to connect the clarifier and
filter with each other, the drain and the existing system shall be
provided by the Contractor. All piping shall be 2‑inch diameter,
threaded, and designed for 125 psi. Not less than seven
hydraulically‑operated diaphragm valves shall be provided to operate the
clarifier/filter train during backwash, clarifier air‑scour, clarifier
air displacement, pre‑conditioning system rinse, and service cycles. The
Contractor shall provide all equipment, valves, controls, and plumbing
to make the filter train fully operational in this application. The
clarifier/filter piping harness shall include necessary apparatus for
air injection. The piping harnesses shall be designed to eliminate any
possibility of a cross‑connection.

E. Controls: The clarifier train shall be equipped with an electrical
panel to control the opening and closing of the diaphragm valves by
means of a pilot valve. The pilot valve shall be electrically, or
hydraulically activated. This control panel shall have provision for
individual adjustment of cycle length times for each of the four cycles
of filter/clarifier backwash, air scour, displacement, and system rinse.

1\. Flow Controls: The filter/clarifier train shall be equipped with
flow controls to regulate the flow of water during backwash and rinse
cycles. They shall be self‑adjusting to prevent media loss and restrict
wastewater discharge. Accuracy of regulation shall be within 15% of the
rated flow over the operating pressure range of the system.

2\. Time Clock: The controller shall be equipped with a timeclock for
initiating backwash on a time or day basis. It shall be adjustable for
any time on a 24 hour clock and any number of days in the week.

3\. Pressure Differential Switch: The controller shall be equipped with
a pressure differential switch so that backwash can be initiated when
the headloss through the system reaches a limit pre‑set by the user. The
switch shall be adjustable within a range of 3 psi to 20 psi.

H. Chemical Feeders: The Contractor shall provide four chemical feed
pumps and chemical holding tanks.

1\. The pumps shall have adjustable pump rates from 0.1 to 1.0 GPH. The
pumps shall be of the positive‑displacement, diaphragm type, capable of
working at 80 psi. The pump shall be powered by an
electronically‑controlled solenoid with manual, indexed, controls for
adjustment of stroke and stroke frequency. The chemical pump housing
shall be made of chemically resistant material such as glass fiber
reinforced thermoplastic with a fiber reinforced polypropylene solenoid
carrier. All exposed fasteners shall be stainless steel. Wetted parts
shall be selected for resistance to the material being pumped.

2\. Chemical Tanks: The chemical feed solution shall be molded
polyethylene with a cover and a minimum capacity of 30 gallons. The tank
shall include strainer and suction valve on the pump uptake. A propeller
type agitator shall be included where required by the chemical being
used. Tanks shall include markings or measuring devices to quickly
determine the amount of contents in the tanks.

3\. Diffusers: Chemical feed pumps shall inject chemicals into the water
stream by in‑stream diffusers which maximize mixing. Diffuser design
shall be approved by the Contracting Officer before installation.

[PART 3: EXECUTION]{.underline}

3.1 PREPARATION:

A. Connections: The Contractor shall perform necessary support work and
modifications to accommodate the filter system, to include connecting
piping and bypass valving.

3.2 INSTALLATION:

A. Requirements: The Contractor shall install all equipment and
supporting utilities.

3.3 FIELD QUALITY CONTROL:

A. Disinfection: The system shall be disinfected according to Section
02675 ‑ Disinfection of Water Distribution Systems.

3.4 ADJUSTMENTS:

A. Start-Up Operations: The Contractor shall put equipment into
operation, adjust chemical feed rates and backflush cycles for optimum
operation. The Contractor shall provide 24 hours of onsite support to
optimize operation of the equipment. Support provided by the Contractor
shall include operation and adjustment of existing equipment onsite. The
Contractor shall maintain a log of all changes and adjustments as well
as any water quality tests performed during this start‑up period.

3.5 DEMONSTRATION:

A. Requirements: Upon completion of installation and after circuitry has
been energized, the Contractor shall demonstrate capability and
compliance of system with requirements. Malfunctioning units shall be
corrected and retested by the Contractor to demonstrate compliance with
the specifications.

3.6 TRAINING OF GOVERNMENT EMPLOYEES:

A. Requirements: See Section 01700 - Contract Closeout.

[PART 4: MEASUREMENT AND PAYMENT]{.underline}

4.1 METHOD OF MEASUREMENT:

A. Units: The work described in this section will not be measured for
payment.

4.2 BASIS OF PAYMENT:

A. Payment: No direct payment for the work described under this section
will be made. The Contractor shall include consideration for this item
in the bid price for other items of the Contract.

END OF SECTION