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THE SPECIFICATION SECTION IN THE CONTRACT

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DIVISION 2:  SITE CONSTRUCTION

SECTION 02241 - DRY WELLS

USE:	Furnishing and installing dry wells.  

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, boldface, and italics, within the paragraphs; and this page.  (Open Reveal Codes [alt F3] to do this accurately.)

	D.	To Edit “(Footer B)”: (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: 

REVISIONS OF THIS SECTION:
CSI format, editorial changes: 12/01
Metric:  
Technical Update:  9/91

SECTION 02241						

DRY WELLS

PART 1:  GENERAL

1.1	SUMMARY

A.	Section Includes:  Furnishing and installing dry wells.

1.2	SUBMITTALS

A.	General:  Submittals shall be according to [Section 01009 - General Information and Requirements]  [Section 01330 - Submittal Procedures] [and] [Section 01331 - Certificates].

B.	Manufacturer's Literature:  Submit three copies of the manufacturer's descriptive data for the rigid insulation.

C.	Shop Drawings:  Submit three copies of the shop drawings for the grate and frame to be used on this project.

D.	Certificates of Conformance:  Submit three copies of written certification from the supplier of the Contractor-furnished gravel aggregates to be used on this project that they conform to the requirements of this specification section.  

1.3	QUALITY ASSURANCE

A.	Failure Criteria:  Not limited to the following:  Units that are warped, broken, cracked, or spalled are not acceptable.

1.5	PROJECT/SITE CONDITIONS

A.	Adjacent Structures:   Gravel around the dry well shall remain intact after backfill for the adjacent structure has been placed. 

PART 2:  PRODUCTS

2.1	MATERIALS

A.	Gravel:  [Shall be from [1/2] to [2 1/2] inches maximum diameter and shall be free from excessive amounts of fines, dust, sand, or clay.]  [The gravel used in the filter pack around the dry well shall have a minimum cross-section 5% larger than the perforations in the concrete sections.]  

B.	Grate:  Shall be [[Standard Convex] [Beehive Grate] [____] with frame, gray iron, according to ASTM A 48, Class 35B, of uniform quality, free from blowholes, shrinkage, distortion, and shall be smooth and well cleaned by shotblasting.] 

C.	Precast Perforated Concrete Sections:  Shall have minimum 1 inch diameter perforations spaced no greater than 2 ft apart in circumference and 1 ft in height.  The overall diameter of the section shall be no less than 4 ft nor greater than 5 ft.  The sections shall be designed so that they key together at the joint and they shall conform to ASTM C 478.

D.	Rigid Insulation:  Shall be extruded polystyrene rigid foam insulation [of thickness according to the drawings] [with a minimum R value of 5.0] and [ a minimum compressive strength of [60 psi], complying with ASTM C 578.

E.	Concrete:  Shall be according to [Section 03306 - Minor Concrete.]  [Section 03310 - Structural Concrete.]

F.	Geotextile Filter:  Shall be synthetic polymer fibers, composed of at lease 85% by weight of polyolephins, polyesters, or polyamides, tensile strength of 80 lb according to ASTM D 1682, puncture strength of 25 lb according to ASTM D 751, a burst strength of 130 psi according to ASTM D 3786, trapezoid strength of 25 lb according to ASTM D 1117, and with apparent opening size less than 0.6 mm.

2.2	FABRICATION

A.	Precast Sections:  Shall be fabricated to the dimensions shown in the drawings within casting tolerances.  Concrete shall be minimum 28 day compressive strength of 3000 psi.

2.3	MIXES

A.	Concrete Mix Design:  Shall be according to [Section 03306 - Minor Concrete.]  [Section 03310 - Structural Concrete.]

2.4	SOURCE QUALITY CONTROL

A.	Concrete Testing:  Shall be according to [Section 03306 - Minor Concrete.]  [Section 03310 - Structural Concrete.]

PART 3:  EXECUTION

3.1	INSTALLATION

A.	[Excavation:] [Drilling:]  Dry holes shall be [excavated] [36 inches in diameter] [drilled] to a depth of [40 ft] [without the use of drilling mud.]  [Drilling] [Excavating] to a depth greater than the water table [plus [5] ft will not be] [allowed.]  [required.]

B.	Compaction:  The bottom of the hole shall be compacted to existing densities before the footing is poured.  Should non-compactable material be encountered, the hole shall be excavated an additional two feet and backfilled with gravel specified in Part 2 before being compacted.  After the dry well is installed, the unclassified fill material over the dry well shall be compacted to the density of the surrounding soil.

C.	Concrete:  Shall be according to [Section 03306 - Minor Concrete.] [Section 03310 - Structural Concrete.]

D.	Precast Perforated Concrete Sections:  Shall be installed, plumb in the hole.  Holes for drain pipe inlets shall be neatly cut or broken in the rings so that the pipes can be grouted in place before the gravel pack covers.

E.	Rigid Insulation:  Shall be installed as indicated on the drawing, to completely cover the concrete top.  Backfill shall be placed so as not to disturb the foam.

F.	Gravel:  The [drilled] [excavated] hole shall be filled with the specified gravel to a depth of [2 inches above the bottom on the concrete apron.]

G.	Precast Concrete Lid:  Shall be installed to cover the rings and support the fill and loads above.

H.	Grate:  Shall be installed as shown on the drawings.

3.2	FIELD QUALITY CONTROL

A.	Inspection:  The interior and exterior of the dry well will be inspected and approved by the Contracting Officer before backfill is placed. 

B.	Testing:  The Contractor shall coordinate testing of piping systems required under Section 15495 - Roof Drainage Piping Systems, before placing precast concrete lid and backfill.

PART 4:  MEASUREMENT AND PAYMENT

	4.1	METHOD OF MEASUREMENT

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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 01009 - GENERAL INFORMATION AND REQUIREMENTS OR SECTION 01010 - SUMMARY OF WORK.

WHEN NOT A "LUMP SUM" CONTRACT, SELECT APPLICABLE PHRASES; USE THE "NO MEASUREMENT" PHRASE WHEN NONE OF THE PAY ITEMS IN THIS SECTION ARE INCLUDED IN THE BID SCHEDULE.
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A.	Units:  The work described in this section will [not be measured for payment.]  [be measured and paid for] [on a lump sum basis.] [by the number of units constructed.]

4.2	BASIS OF PAYMENT

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WHEN NOT A "LUMP SUM" CONTRACT, SELECT APPLICABLE PHRASES; USE THE "NO DIRECT PAYMENT" PHRASE WHEN NONE OF THE PAY ITEMS IN THIS SECTION ARE INCLUDED IN THE BID SCHEDULE.

WHEN NOT A "LUMP SUM" CONTRACT AND PAYMENT IS TO BE MADE UNDER THIS SECTION, SELECT APPLICABLE PAY ITEMS.  DO NOT CHANGE PAY ITEM NUMBER.
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A.	Payment:  [No direct payment for the work described under this section will be made.  Consideration for this item shall be included in the bid price for other items of the Contract.]  [Prices and payment will be full compensation for the work described in this section.  Payment will be made under:]

Pay Item												Pay Unit

		02241(01)  Dry Well . . . . . . . . . . . . . . . . . . . . . Lump Sum
	02241(02)  Dry Well . . . . . . . . . . . . . . . . . . . . . Each

END OF SECTION