Attachment_13_Section_33_36_13.13_Precast_Concrete_Tanks_Final.pdf

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PRECAST CONCRETE TANKS

SECTION 33 36 13.13

PART 1 - GENERAL

1.1 SCOPE OF WORK

A. Furnish, deliver, install, and connect precast concrete sewer manholes, the wastewater grinder pump lift station vault, the appurtenant valve vault, and other valve vaults associated with the influent water lines from the wells to the treatment system.

1.2 REFERENCES

A. ASTM C 890 - Standard for Waste Water Structures

B. ASTM C 318 - Standard for Reinforced Concrete

1.3 QUALITY ASSURANCE

A. All precast concrete tanks are to be designed by Professional Civil & Structural Engineers licensed in the State of Washington.

B. All tanks are designed and constructed to be one hundred percent (100%) watertight.

Manufacturing processes shall provide detailed and comprehensive quality control procedures consistent with the National Precast Concrete Associations Plant Certification Program. Inlet and outlet pipe connections have gaskets to prevent leakage.

C. All building connections from buildings shall be made in accordance with the Uniform

Plumbing Code.

1.4 SUBMITTALS

A. Submit detailed dimensional drawings to the Contracting Officer ten (10) days prior to installation prepared and stamped by a Washington licensed professional engineer showing the lift station pump vault and dry pit valve vaults and its appurtenances along with anti-buoyancy measures that assume a ground water level equal to ground surface level. Also provide copies of manufacture’s literature, materials of construction and any other information necessary to determine compliance with the plumbing code, specifications and project requirements.

1.5 WARRANTY

RFP 140P8319R0001

Attachment # 13 Revised Section 33 36 13.13

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A. The overflow tank and grease interceptor manufacturer shall provide a minimum two (2) year warranty for lift station vault and valve vault tank defects, cracks, or failure to maintain watertight conditions. Lift station and valve vaults and their appurtenances found defective within two (2) years shall be replaced by the manufacturer at no additional cost to the government.

PART 2 - PRODUCTS

2.1 PRECAST CONCRETE TANKS

A. The tank shall be constructed of reinforced concrete, meeting ASTM C1613. Reinforced

Pre-cast concrete construction shall use concrete meeting four thousand (4,000) psi at twenty-eight (28) days. Tank shall not be moved from the manufacturing site to the project site until the tank has cured for at least fourteen (14) days or has reach two-thirds (2/3) of the design strength. Reinforcement steel shall be ASTM A615 Grade 60 fy = 60,000 psi.

B. The pre-cast tank shall be connected to a pump vault in accordance with contract drawings and Uniform Plumbing Code requirements.

C. All tanks shall be structurally sound and watertight and shall be guaranteed in writing by the tank manufacturer for a period of two years from the date of final acceptance. The tank guarantee/warranty shall be furnished at the time of submittal. Tank warranty shall not be limited liability to replacement cost of the tanks. The pre-cast tank shall be capable of withstanding long-term hydrostatic loading, in addition to the soil loading, due to a water table maintained at ground surface.

D. The pre-cast tanks and valve vaults shall be designed to accommodate AASHTO H20 loadings.

E. Tanks shall be manufactured and furnished with access openings in accordance with the plans. Modification of completed tanks will not be permitted.

F. All tanks shall be installed in strict accordance with the manufacturer's recommended installation instructions.

PART 3 – EXECUTION

3.1 INSTALLATION AND QUALITY CONTROL

A. The lift station tank and valve vault tanks shall be installed level on a solid bed, minimum six inches (6”) thick compacted granular bedding overlying a firm uniform base. Backfill must be performed on all sides simultaneously tamped in place and compacted to a minimum ninety percent (90%) of maximum dry density as tested in accordance with ASTM D 698 or manufacturer’s specifications. Ensure that select backfill is used within twelve inches (12”) of the tank and vault.

B. An experienced lift station tank and and inspection vault installer with at least five (5) years of tank installation experience shall be used to install the lift station tank and valve vault tank and appurtenances.

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C. The tank and vault manufacturer and its installer shall certify the tanks are sound, free of defects, and demonstrate the tanks are water tight.

D. All piping and appurtenances inside of the tank shall be appropriately installed in accordance with manufacturer recommendations. Work shall be performed to code and as required by

Section 22 00 00 – Plumbing General Requirements.

END OF SECTION