Specification- Septic Tank Systems.pdf

TECHNICAL SPECIFICATIONS

White Sands Missile Range

Directorate of Public Works

SECTION 333600 - SEPTIC TANK SYSTEMS

PART 1 - GENERAL

1.1 RELATED DOCUMENTS

A. Drawings and general provisions of the Contract, including General and Supplementary

Conditions and Division 01 Specification Sections, apply to this Section.

1.2 SUMMARY

A. Section Includes:

1. Septic tanks.

2. Distribution boxes.

3. Absorption systems.

1.3 ACTION SUBMITTALS

A. Product Data: For each type of product indicated.

1. Include construction details, material descriptions, dimensions of individual components, and profiles.

2. Include manhole openings, covers, and pipe connections.

B. Shop Drawings: For trench absorption systems, bed absorption systems, mound absorption systems and/or seepage pits.

1. Include manhole openings, covers, pipe connections, and accessories.

2. Include piping with sizes and invert elevations.

3. Include underground structures.

4. Include other utilities.

1.4 PROJECT CONDITIONS

A. Interruption of Existing Septic Tank System Service: Do not interrupt service to facilities occupied by Owner or others unless permitted under the following conditions and then only after arranging to provide temporary service according to requirements indicated:

1. Notify Owner no fewer than two days in advance of proposed interruption of service.

2. Do not proceed with interruption of service without Owner’s written permission.

1.5 REGULATORY REQUIREMENTS

A. Applicable regulations include, but may not be limited to:

1. New Mexico Environmental Department NMAC 20.7.3

2. 2021 International Plumbing Code

PART 2 - PRODUCT

2.1 POLYETHYLENE SEPTIC TANKS

A. Description: Molded, HDPE or PE construction; fabricated for septic tank application; two chambers each with an access riser and manhole.

B. Manholes: 18-inch-, 20-inch- or 22-inch- as specified minimum diameter opening with HDPE or PE access risers to grade and cover.

C. Filter Access: Include access hole, large enough to remove filter, over filter position.

D. Resilient Connectors: ASTM C 923 or other watertight seal, of size required for piping, fitted into inlet and outlet openings.

E. Capacity and Characteristics:

1. Capacity: 1,000 gallons.

2. Inlet and Outlet Size: As specified.

2.2 FILTERS

A. Description: Removable, septic-tank-outlet filter that restricts discharge solids to 1/8 inch.

B. Housing: HDPE or PVC.

C. Outlet Size: NPS 4 or NPS 6 as specified.

2.3 PLASTIC DISTRIBUTION BOXES

A. Description: Molded-HDPE or -PE, single-chamber box and cover.

B. Manholes: Manufacturer's standard cover or other access opening of size that permits access to distribution-box inlet and outlets.

C. Pipe Connections: With seal that prevents leakage. Include watertight plugs in outlets not required.

D. Capacity and Characteristics:

1. Inlet Size: As specified.

2. Number of Outlets: As specified.

3. Outlet Size: As specified.

2.4 TRENCH OR BED ABSORPTION-SYSTEM MATERIALS

A. Filter Material: ASTM D 448, Size No. 24, 3/4 to 2-1/2 inches, washed, crushed stone or gravel; or broken, hard-burned clay brick.

B. Filter Mat: Geotextile woven or spun filter fabric, in one or more layers, for minimum total unit weight of 3 oz./S.Y.

C. Fill Material: Soil removed from trench.

PART 3 - EXECUTION

3.1 EARTHWORK

A. Excavating, trenching, and backfilling for piping and seepage pits are specified in

Section 02300 "Earthwork."

1. Stockpile topsoil for reuse in finish grading without intermixing with other excavated material. Stockpile materials away from edge of excavation and do not store within drip line of remaining trees.

2. Place, grade, and shape stockpiles to drain surface water. Cover to prevent windblown dust.

B. Excavating and Backfilling for Septic Tanks:

1. Excavate sufficient width and length for tanks to depth determined by tank inlet elevation. Provide level bottom.

2. Backfill with excavated soil, mounding soil above original grade without compacting.

C. Excavating and Backfilling for Trench Absorption Systems:

1. Excavate for trench absorption systems 36 inches wide and 28 inches deep, minimum.

2. Backfill with excavated soil, mounding soil above original grade without compacting.

D. Excavating and Backfilling for Chamber Absorption Systems:

1. Excavate for trench-type chamber absorption systems as indicated deep, minimum.

2. Excavate for bed-type chamber absorption systems of width and depth indicated.

3. Backfill chamber absorption systems with excavated soil, mounding soil above original grade without compacting.

3.2 SEPTIC TANK INSTALLATION

A. Install septic tanks level.

B. Connect septic tank to inlet septic pipe.

C. Install filter in septic tank outlet. Secure filter to septic tank wall. Make direct connections to distribution piping.

D. Fill septic tank with water.

3.3 DISTRIBUTION BOX INSTALLATION

A. Install PE distribution boxes at invert elevations indicated and according to manufacturer's written instructions. Set level and plumb.

3.4 PIPING INSTALLATION

A. Comply with requirements for sewer pipe installation specified in Section 02530 "Sanitary

Sewerage."

B. Install distribution piping according to the following:

1. PE Tube and Fittings: ASTM F 481.

2. PVC Sewer Pipe and Fittings: ASTM F 481.

3.5 PIPE JOINT CONSTRUCTION

A. Join distribution piping with or according to the following:

1. Install pipe and fittings for trench, bed or mound absorption systems with closed joints unless otherwise indicated.

2. PE Tube and Fittings: With PE band couplings.

3. PVC Sewer Pipe and Fittings: With solvent-cemented joints according to ASTM F 402 and ASTM D 2321.

B. Join dissimilar pipe materials according to ASTM D 5926, with couplings and gaskets compatible with pipe materials being joined.

3.6 TRENCH OR BED ABSORPTION-SYSTEM INSTALLATION

A. Filter Material: Place supporting layer of filter material over the compacted trench or bed base to a compacted depth not less than 6 inches below bottom of pipe.

B. Install sewer piping at minimum slope of 1 percent and maximum slope of 2 percent unless otherwise specified.

C. Install distribution piping solidly bedded in filter material, with full bearing for each pipe section throughout its length. Maintain pipe alignment with no slope.

1. Install perforated pipe with perforations down and joints tightly closed. Install couplings as required.

2. Install elbow fittings with tight joints.

3. Install absorption-system materials as follows from surface of excavation to grade:

a. Trench Size: As specified.

b. Bed Size: As specified.

c. Bottom Filter Material Layer: As specified.

d. Intermediate Filter Material Layer: As specified.

e. Top Filter Material Layer: As specified minimum thickness above distribution piping.

f. Filter Mat: Above final filter-material layer.

g. Fill: Above filter mat to final grade.

D. Install filter mat over filter material before backfilling.

3.7 MOUND ABSORPTION-SYSTEM INSTALLATION

A. Place layers of sand, aggregate, cap, and topsoil above prepared/excavated bottom area. Provide grass topping to match adjacent vegetation. Provide side slope not steeper than 3:1. Tie slope toe smoothly into existing grade.

B. Provide solid vent pipe with vent cap extending as specified.

C. Install sewer piping as specified.

D. Install distribution piping solidly bedded in filter material, with full bearing for each pipe section throughout its length. Maintain pipe alignment with no slope.

3.8 CHAMBER ABSORPTION-SYSTEM INSTALLATION

A. Install sewer piping as specified.

B. Install chambers with no slope above plowed area.

1. Install chamber distribution piping with tight joints throughout chambers.

3.9 IDENTIFICATION

A. Identification materials and their installation are specified in Section 02300 "Earthwork."

Arrange for installation of green, detectable warning tape directly over piping, at outside edges of underground structures, and at outside edges of absorption systems.

3.10 FIELD QUALITY CONTROL

A. System Tests: Perform testing of completed septic tank system piping and structures according to New Mexico Environmental Department NMAC 20.7.3.

B. Additional Tests: Fill underground structures with water and let stand overnight. If water level recedes, locate and repair leaks and retest. Repeat tests and repairs until no leaks exist.

3.11 CLEANING

A. Clear interior of piping and structures of dirt and other superfluous material as work progresses.

B. Maintain swab or drag in piping, and pull past each joint as it is completed. Place plugs in ends of uncompleted pipe at end of workday or when work stops.

END OF SECTION 333600

Specification- Septic Tank Systems