Hermosa Lagoon Expansion_Benesch Project Manual_v4_ and Appendices A and B.pdf

PROJECT MANUAL

Lagoon Expansion Project CWSRF No. C461278-03 Hermosa

Custer County, South Dakota

Prepared for

Town of Hermosa

230 Main Street

Hermosa, SD 57701

November 2024

Project No. 00112515.00

11/5/2024

PROJECT DIRECTORY

HERMOSA LAGOON EXPANSION

BENESCH PROJECT NO. 00112515.00

Owner:

Town of Hermosa

PO Box 298

230 Main Street

Hermosa, SD 57744

Contact:

Terri Cornelison

Finance Officer terri@hermosasd.com

(605)-255-4291

Civil Engineer & Wastewater Engineer:

Benesch

825 M Street, Suite 100

Lincoln, NE 68508

Contact:

Anthony Theodorou, PE, Senior Project Manager atheodorou@benesch.com

(605)-910-7095 Direct

(605)-569-3646 Cell

TABLE OF CONTENTS

PLANS AND SPECIFICATIONS FOR

HERMOSA LAGOON EXPANSION PROJECT

BID REQUIREMENTS AND CONTRACT DOCUMENTS

Section 0 – Information Summary …………………………………………………………………........................... 1 pages

Section 1 – Advertisement for Bids …………………………………………………………………......................... 2 pages

Section 2 – Instructions to Bidders ……………………………………………………………………………............ 11 pages

Section 3 – Insurance Requirements ……………………………………………………………………………......... 2 pages

Section 4 – Bid Items ……………………………………………………………………………………………................... 3 pages

Bidder’s Proposal …………………………………………………………………………………………….... 3 pages

Section 5 – Contract Documents ………………………………………………………………………………………. 4 pages

Performance and Payment Bond……………………………………………………………............... 2 pages

Bid Bond………………….……………………………………………………………………………….............. 1 pages

Section 6 – Notice of Award ………………………………………………………………………………………............ 1 pages

Notic to Proceed……………………………………………………………………………………................ 1 pages

Section 7 – Supplemental Conditions ………………………………………………………………………………........ 5 pages

Section 8 – Detailed Specifications ……………………………………………………………………………................. 14 pages

APPENDICES

Appendix A – AET Geotechnical Report........................................................................................................... 27 pages

Appendix B –State Revolving Fund General Conditions……………………….………………………..……….. 55 pages

PROJECT PLANS

Hermosa Lagoon Expansion ................................................................................................................................ 10 pages

SECTION 0 INFORMATION SUMMARY

Page | 1

SUBJECT INFORMATION PRIMARY STATEMENT

OF SUBJECT MATTER

PRE-BID

CONFERENCE: November 20, 2024 Advertisement for Bids; Page 2

Town of Hermosa Lagoon

389 Fairgrounds Pl

LAST QUESTIONS ACCEPTED: November 22, 2024

BID DATE: December 2, 2024

Town of Hermosa Offices

Advertisement for Bids; Page 1

230 Main St.

COMMENCEMENT:

COMPLETION:

By April 1, 2025

By October 31, 2025

Bidders Proposal; Page 3

Bidders Proposal; Page 3

LIQUIDATED DAMAGES:

$12,500 and $100/day substantial for both commencement and completion

Contract Documents; Page 1

WARRANTY BONDS: Supplemental Conditions; Page 4

In case of a discrepancy, the information provided at the location of the primary statement of subject matter shall govern.

+ +END OF INFORMATION SUMMARY+ +

SECTION 1 ADVERTISEMENT FOR BIDS

OWNER: Town of Hermosa

PO Box 298

Hermosa, SD, 57744

Benesch Project No. 00112515.00

ADVERTISEMENT FOR BIDS

The Town of Hermosa will be accepting sealed bids for the Hermosa Lagoon Expansion project until

2:00 P.M., December 2, 2024 at the Town of Hermosa Offices, 230 Main St., Hermosa, SD 57744, at which time the bids will be publicly opened and read aloud. The project will consist of the following.

Base Bid: This project includes furnishing materials, equipment, labor, and performing all work detailed in the HERMOSA LAGOON EXPANSION Plan and Specifications, including but not limited to the construction of a Pump Station, 4’ Dia. Manholes, 4” SDR 11 force main pipe 400 LF, 4” CL-54 D.I. pipe

238 LF, 4” SCH-80 PVC pipe 415 LF, 8” SCH-80 PVC pipe 532 LF, 12” SCH-80 PVC pipe 60 LF, including all pipework accessories, flow meter, pumps, controls, valves, and pump accessories. Earthwork includes a cut volume of 36,738 CU. YD, a fill volume of 19,209 CU. YD, Bentonite Liner of 189,000 SF and 700 CU YD. of gravel driveways. This project also includes fence installation, conduit, soil erosion control and grass restoration work as well as items listed in the bid schedule.

All work shall be performed in accordance with the City of Rapid City Specifications for Public Works

Construction, 2022 Edition. The successful bidder shall provide all materials, labor, equipment, and incidental items necessary to complete the work per the contract documents.

Contracts for work described in these Bidding Documents obligate the Contractor and Subcontractors to follow the South Dakota State Revolving Fund Specifications described in the State Revolving Funds

General Conditions Appendix and to be non-discriminatory in their employment practices.

There is regulation which concerns utilization of Disadvantaged/Minority Business Enterprises

(DBE/MBE) and Women’s Business Enterprises (WBE). The goal for MBE is 1.0% of the total dollar value of the project. The goal for WBE is 4.0% of the total dollar value of the project. The Owner does not discriminate on the basis of race, color, national origin, sex, religion, age, or disability, and are required to comply with the Equal Opportunity Clause published at 41 CFR Part 60 and Executive Orders 11246, 11518, and 11625, as amended. Bidders on this work will be required to comply with the President’s

Executive Order No. 11246 (Equal Employment) and the regulations in 41 CFR Part 60 – 1.4(b).

Bidders on this work will be required to comply with Public Law 115-232 Prohibition of Certain

Communication Technologies.

Davis-Bacon and Related Acts wages apply to this project in its entirety. All provisions relative to those acts must be met. Wage rate determinations for the project have been included in Instructions to

Bidders Sec 2.23.

The low, responsive bidder will be required to certify to compliance with the American Iron and Steel

SECTION 1 ADVERTISEMENT FOR BIDS

Page | 2 provision of the Consolidated Appropriations Act of 2014. This certification form may be found on page AIS-21 and 22 of the State Revolving Fund (SRF) General Conditions and must be included in the bid proposal.

Please be advised that waivers or exemptions from the American Iron and Steel provision that cite

International Trade Agreements DO NOT comply with the Consolidated Appropriations Act of 2014 as it applies to the SRF programs. Claims from suppliers that the American Iron and Steel provision does not apply to certain products based on the International Trade Agreement exemptions of the

Consolidated Appropriations Act of 2014 will not be accepted.

This project may be partially funded using American Rescue Plan Act (ARPA) funds. As a condition of the ARPA funding guidelines, the Contractor shall meet the minimum requirements outlined in the

Instructions to Bidders, Article 2.20.

Prospective Bidders may examine the Bidding Documents at the Town of Hermosa Office on Mondays through Fridays between the hours of 8:00 am and 5:00 pm and may obtain copies of the Bidding

Documents from the Town of Hermosa Offices as described below. Printed plans and specifications for the project may be obtained from the Town of Hermosa Offices, 230 Main St., Hermosa, SD 57744, WITH A $120.00 REFUNDABLE DEPOSIT. Bidding documents are also available on a flash drive (as portable document format (PDF) files) for a non-refundable charge of $10.00, excluding shipping charges. There is no P&S fee for South Dakota Bidders.

The pre-bid conference will be held at 2:00 p.m. local time on, November 20th, 2024 at the Town of

Hermosa Lagoon, 389 Fairgrounds Pl, Hermosa, SD 57744. Attendance at a pre-bid conference is not mandatory. Last Questions accepted at 5:00 p.m. local time, November 22,, 2024.

Bids shall be submitted on the Bid Forms provided and in accordance with the Bidding Documents.

No bids will be considered unless sealed and filed at the Town of Hermosa Office, 230 Main St., Hermosa, SD 57744. Each bid must be accompanied by a certified check, cashier's check or a bank draft drawn on a State or National Bank for five percent (5%) of the amount bid, payable to the Town of

Hermosa or in lieu thereof, a bid bond for ten percent (10%) of the amount bid by a surety authorized to do business in the State of South Dakota, payable to the Town of Hermosa, as a guarantee of the bidder entering into a contract with the Town of Hermosa for the HERMOSA LAGOON EXPANSION.

The checks of all unsuccessful bidders will be returned within thirty (30) days after the bids have been opened. Any deficient Bid will be resealed and returned to the Bidder.

The Owner reserves the right to reject any and all bids and to waive any irregularities or informalities therein and to award the Contract in the best interests of the Owner. The Contractor shall be able to demonstrate that he has successfully completed municipal work of a similar nature and scope as that required for the project. No Bidder may withdraw their bid for a period of thirty (30) days after the bid opening. The Owner will award the bid within ten (10) days after the bid opening and/or at the next board of trustees meeting (1st and 3rd Tuesday of the month).

+ + END OF ADVERTISEMENT FOR BIDS + +

SECTION 2 INSTRUCTIONS TO BIDDERS

Page | 11

2.28 FEES, PERMITS AND TAXES

The Contractor shall obtain all necessary permits associated with the project. Including but not limited to erosion control permits, SWPPP permits, utility connection fees, tapping fees, and all other fees, taxes and costs shall be borne by the Contractor.

2.29 PRE-BID CONFERENCE

All Bidders on this project are highly encouraged to attend the pre-bid conference, but attendance is not mandatory. Interested contractors will have the opportunity to gain a full knowledge of the work involved, the bidding procedure, and other information required to prepare and submit their bid. They will be held at the following time and place:

Wednesday, November 20 @ 2:00 p.m.

Town of Hermosa Lagoon

389 Fairgrounds Pl

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SECTION 4 BIDDERS PROPOSAL

BIDDER'S PROPOSAL FOR

FURNISHING LABOR, EQUIPMENT, AND MATERIALS

FOR THE CONSTRUCTION OF:

Hermosa Lagoon Expansion

Benesch Project No. 00112515.00

PLACE: Town of Hermosa Offices

230 Main St.

DATE/TIME: 2:00p.m. Local Time, Monday, December 2, 2024

TO: Town of Hermosa

PO Box 298

230 Main Street

In compliance with your invitation for bids to furnish all necessary labor, tools, materials, and equipment to construct complete in all detail.

Hermosa Lagoon Expansion complete and ready for use as shown on the detailed plans and specifications, the undersigned Bidder, 1) a Corporation organized and existing under the laws of South Dakota,

2) A Partnership consisting of

3) An Individual D/B/A

Of the City of State of having examined the detailed plans and specifications and contract with bond hereto attached, and being fully advised of the materials to be furnished and the work to be done in the construction of the said project, does hereby propose to furnish all necessary labor, tools, materials, and equipment and do all the work as specified to fully complete said work as shown by said plans and specifications, and as shown on said Bidder’s Proposal.

The Bidder's Proposal is based upon the conditions and stipulations within the Contract Documents and shall be considered a part of this Contract as if written herein at length. The work to be performed under this Contract shall commence within ten (10) calendar days after the

Contractor is notified by the Owner to proceed.

The contract award will be based on the lowest bid price arrived at in accordance with the Bid

Schedule set forth below.

The said Bidder further agrees and states that he/she has read the advertisement calling for bids, has studied the Contract Documents, is familiar with the terms and conditions stipulated therein, agrees to enter into the attached Contract, and acknowledges the receipt of the following Addenda.

Addenda No. Dated

Name of Company (Party of the Second Part)

Authorized Representative

Authorized Signature Date

Title

Address

Phone Number

Fax Number

Email

SD Sales & Use Tax No.

SD Contractor’s Excise Tax License No.

Page | 3

SPECIAL BID CONDITIONS AND

EXPLANATION OF BID SCHEDULES

1. All work as shown in the Hermosa Lagoon Expansion, Benesch Project No. 00112515.00 shall commence by the following:

a. April 1, 2025, for all work shown in the project plans within the project limits.

Liquidated damages will be charged for failure to commence the project on or before the completion dates.

2. All work as shown in the Hermosa Lagoon Expansion, Benesch Project No. 00112515.00 shall be completed by the following:

a. October 31, 2025, for all work shown in the project plans within the project limits.

Liquidated damages will be charged for failure to complete the project on or before the completion dates.

3. Work on the project cannot start without prior authorization from the Engineer.

4. The project work shall be bid by unit prices as provided in the Bidder’s proposal and shall include sales tax and all other applicable taxes and fees.

5. Payment will be made for actual work completed in accordance with payment conditions explained in this Project Manual.

6. In the case of an error in the extension of a unit price to an item total, the unit price shall govern, and the corrected item total used in evaluating bids. In case of an error in the summation of bid item totals, the corrected summation will govern the incorrect bid total shown.

7. Weather days shall be considered for completion date extensions.

8. Bid award will be made to the lowest responsive and responsible bidder. The Owner reserves the right to select the Base Bid and/or the Alternates whichever is in the Owner’s best interest.

9. Final Completion includes completion of all work including site stabilization as required by the

Contract Documents.

10. Estimated Start Date is to be December of 2024 pending agreements and permitting approval from Town, State, and County agencies.

SECTION 8 DETAILED SPECIFICATIONS

DETAILED SPECIFICATIONS FOR

HERMOSA LAGOON EXPANSION

1. MOBILIZATION

A. Payment

When there is a bid item for "Mobilization" in the Bid Proposal, payment for this item will be made for preparatory work and operations performed by the Contractor, including, but not limited to those necessary for the movement of his personnel, equipment, supplies, and incidentals to the project site;

for the establishment of all offices, buildings, and other facilities necessary for work on the project; and for other work operations that must be performed, or for cost incurred before beginning work on the various items on the project site.

2. POND BYPASS

A. General

The two west ponds (Cell A and C) are connected to each other and will remain untouched during the construction phase. Cell A is the current primary cell and Cell C is the current secondary cell. South of Cell C, the wastewater treatment plant will be constructed. During construction of the new ponds, Cell A and C shall treat all flows from the town pending the wastewater treatment plant construction and commissioning

3. CONSTRUCTION STAKE OUT

This work shall consist of furnishing and placing construction stakes necessary to construct the project.

The staking work includes establishing project centerline; re-establishing plan and Network control points; setting additional benchmarks and control points as needed; measuring volumes of necessary topsoil stockpiles; topographic surveys for final cross sections earthwork quantities; verifying undercut, muck, rock and dig-out removal quantities; staking right-of-way (ROW), easements, and project limits;

and other miscellaneous construction survey work.

The surveyor performing work under this section shall either be licensed or shall be under the direct supervision of a Registered Land Surveyor. Surveyor shall perform all construction layout and reference staking necessary for accurate control and completion of all structure construction, grading, paving, drainage, fence, permanent control points, ROW monuments and all other appurtenances required for the complete construction and acceptance of the work. The layout shall include, but not be limited to, staking clearing line; removal limits; slope staking and slope stake referencing; grade staking (blue top dirt grade and base course grade hubs); paving hub staking; staking of water mains, fittings, hydrants and valves; staking of sewer mains, bends, manholes, and services; staking of culvert pipes and structures; re-establishing property corners; and performing the miscellaneous staking as described in the plans and in these specifications.

4. MANHOLE

This work consists of furnishing and installing sanitary sewer mains, manholes, service lines, and appurtenances. This includes all equipment, tools, materials, labor, and other incidentals to provide sewer mains and service lines complete and ready for use. The work also includes, but is not limited to, all necessary excavation, backfilling, compaction, testing, clean up, and restoration. All connections to the City sanitary sewer system, directly or indirectly, need to be designed and constructed in accordance with City Criteria.

B. Materials

1. Manholes shall be pre-cast reinforced concrete, manufactured using Type II cement, and shall have diameters as shown on the plans. The manholes shall be manufactured at a precast facility that is certified by the American Concrete Pipe Association, is approved for supplying manholes to the South

Dakota Department of Transportation, or has been approved by the Engineer. Manholes 48 inches in diameter shall meet the current requirements of ASTM-C-478.

2. Pipe Connections to Existing Manholes: Are not allowed unless prior approval of the Engineer has been obtained. If approved the connection shall be made by coring the existing manhole and installing a boot-type flexible connector consisting of a rubber gasket or boot, metal expansion ring and double metal take-up clamps, as manufactured by Press Seal Gasket Corporation, or approved equal. A stainless steel “power sleeve” shall be supplied for connecting the boot to the manhole. The boots shall be type PSX as manufactured by Press Seal Gasket Corporation or approved equal. Rubber boots and gasket material shall meet or exceed ASTM C-923. The existing manhole inverts shall be reconstructed to meet specifications. Refer to Section 9.3 regarding Construction Requirements and the Standard Detail for further guidance with this installation.

C. Basis of Payment

1. Standard Manhole, Standard Shallow Manhole, and Termination Manhole: 0 - 6 feet. Payment will be made at the unit price bid for each type and diameter, furnished and installed including but not limited to the following ancillary items to the manhole: adjusting rings, frame, cover and external joint seals

2. Sanitary Sewer Cleanouts: Payment will be at the unit price bid for Sanitary Sewer Cleanout furnished and installed, including all labor and materials.

5. FORCE MAIN

A. Materials

Polyvinyl Chloride (PVC) Pipe and Fittings 4 Inch and larger - Shall conform to Section 8A Water Piping

Systems, subsection 8A.2 Materials and Section 8B – Corrosion Protection – Plastic Pipe Systems. PVC force main shall utilize a green dye resin for color in order to represent wastewater or a green locator

Page | 3 ribbon with the word “sewer” stenciled shall be used.

6. PVC PIPE

A. Materials

PVC Pipe and Fittings: 4 inches through 15 inches diameter, shall conform to the requirements of ASTM

D-3034, Type PSM, SDR-35 minimum. PVC pipe 18 inches through 24 inches diameter shall conform to the requirements of ASTM F679, minimum wall thickness T-1. PVC pipe shall be manufactured in a continuous extrusion process employing a prime grade of un-plasticized PVC plastic material that meets the requirements for this product as specified in ASTM D1784. The pipe shall be made of PVC plastic having a cell classification of 12454-B, 12454-C, 12364-C, or 13364-B. SDR-35 is a minimum and the design engineer shall determine if depths and soil conditions require additional wall thickness.

PVC Sewer Pipe shall have a flexible elastomeric seal (O-ring or rubber sealing elastomeric gasket joint), and conform to the latest revisions of ASTM D3212. Solvent cement joints are not allowed for sewer pipe and fittings.

Nominal laying lengths shall not be less than 12.5 feet, except shorter lengths may be used adjacent to manholes and for the installation of inline wyes and tees. Each length of pipe shall be marked, as a minimum, with size, SDR, "Sewer Pipe" and ASTM number.

B. Basis of Payment

1. Sewer Main Pipe: Payment will be at the unit price bid for the appropriate size and depth of sewer pipe, furnished and installed, including trenching, excavation, Type 1 bedding material, compacting, backfilling, dewatering, sheeting or shoring, compaction, and testing.

2. Sewer Service Pipe: Payment will be made at the unit price bid for the appropriately sized pipe, furnished and installed, including trenching, excavation and backfilling, bedding material, compacting, dewatering, tracing wire, and sheeting or shoring. The cost for any connections between the new service line and existing service lines shall be included in the unit price bid for the appropriate sized pipe.

7. GATE VALVES IN BOX

Valve Box for Gate Valves 12 Inches and Smaller and All Butterfly Valves: Shall be a 2-piece screw-type construction with five and one-fourth (5 1/4) inches riser and shall be adjustable from four and one half (4 1/2) feet to 6-feet, with the top section to be at least 24 inches in length. Drop lids shall be marked "Water" and are to be of all-metal construction. Acceptable Products are Tyler 6850-666-S series heavy duty valve box with adapter; or approved equal.

B. Installation

Valve Boxes: Shall be installed straight and plumb directly over the valve stem and placed over a valve box adaptor. The top of the valve box shall be placed flush to ¼ inches below flush with the surfacing

Page | 4 in paved or graveled areas and shall be flush with the finished grade in grass surfaced areas. Where the construction plans indicate that the future grade at the valve location will be higher or lower than the existing grade at the time of valve installation, the Contractor shall provide the correct combination of extension pieces so that the valve box can be adjusted to the future finished grade without replacing the valve box. A Valve Box Adaptor shall be installed on the valve bonnet prior to installing the valve box. The Valve box shall be wrapped with polyethylene.

8. 6’ HIGH CHAIN LINK FENCE

The entire pond area shall be enclosed with a suitable fence to provide for public safety, to exclude livestock, and to discourage trespassing. The pond area should be fenced with at least 6-foot woven wire and two strands of barbed wire at the top. A vehicle access gate of minimum 12-foot width to accommodate mowing equipment should be provided unless the installation is small;

then 8 foot will be satisfactory. All access gates shall be provided with locks. Fences shall be located away from the outside toe of the dike to facilitate dike mowing and maintenance operations.

Warning Signs: Appropriate signs should be provided along the fence around the pond to inform the public of the facility and advise against trespassing. A minimum size of 20 inches by 12 inches with a minimum size letter of two inches is recommended. There shall be at least one such sign on each side of the pond and every 500 feet along the fence.

9. EXISTING 6’ HIGH CHAIN LINK FENCE RELOCATED

Cavities left by structure removal shall be filled to the level of the surrounding ground and shall be compacted to the satisfaction of the Engineer under the same specifications as embankment.

B. Remove and Salvage

Designated salvageable material shall be carefully removed in sections or pieces, which may be readily transported and shall be stored at places specified.

10. EARTHWORK

1. Comply with local codes, ordinances, and requirements of agencies having jurisdiction. Slope sides of excavations to comply with local codes, ordinances, and requirements of agencies having jurisdiction. Shore and brace where sloping is not possible because of space restrictions or stability of material excavated. Maintain sides and slopes of excavations in safe condition until completion of backfilling. The contractor is responsible for the stability and safety of all excavated

Page | 5 areas.

2. Dewatering: Prevent surface water and subsurface or ground water from flowing into excavations and from flooding project site and surrounding area. Do not allow water to accumulate in excavations. Remove water to prevent softening of foundation bottoms, undercutting footings, and soil changes detrimental to stability of sub-grades and foundations. Provide and maintain pumps, well points, sumps, suction and discharge lines, and other dewatering system components necessary to convey water away from excavations.

3. Establish and maintain temporary drainage ditches and other diversions outside excavation limits to convey rainwater and water removed from excavations to collecting or runoff areas. Do not use trench excavations as temporary drainage ditches.

4. Storage: Stockpile excavated materials acceptable for backfill and fill where directed. Place, grade, and shape stockpiles for proper drainage. Locate and retain soil materials away from edge of excavations. Stockpile on site, as directed, the excess excavated soil material and materials not acceptable for use as backfill top-soil or fill.

5. Excavations for Pavements: Cut surface under pavements to comply with cross-sections, elevations and grades as indicated.

6. Trench Excavation for Pipes: Excavate trenches to uniform width, sufficiently wide to provide ample working room and a minimum of one foot of clearance on both sides of pipe or conduit. Excavate trenches and conduit to depth indicated or required to establish indicated slope and invert elevations and to support bottom of pipe or conduit on undisturbed soil. Beyond building perimeter, excavate trenches to allow installation of top of pipe below frost line or to the depth indicated on the contract drawings. For pipes or conduit less than 6 inches in nominal size, and for flat-bottomed, multiple-duct conduit units, do not excavate beyond indicated depths. Hand-excavate bottom cut to accurate elevations and support pipe or conduit on undisturbed soil. For pipes and equipment 6 inches or larger in nominal size, shape bottom of trench to fit bottom of pipe for 90 degrees (bottom 1/4 of the circumference). Fill depressions with tamped sand backfill.

At each pipe joint, dig bell holes to relieve pipe bell of loads ensure continuous bearing of pipe barrel on bearing surface.

7. Cold Weather Protection: Protect excavation bottoms against freezing when atmospheric temperature is less than 35 degrees F.

11. FILL MATERIAL

Place soil material in layers to required subgrade elevations, for each area classification:

1. Under grassed areas, use satisfactory excavated or borrow material.

Page | 6

2. Under walks and pavements, use subbase material.

3. Under piping and conduit and equipment, use subbase materials where required over rock bearing surface and for correction of unauthorized excavation. Shape excavation bottom to fit bottom 90 degrees of cylinder.

12. GRADING AND COMPACTION

A. Grading

Uniformly grade areas within limits of grading under this section, including adjacent transition areas. Smooth finished surface within specified tolerances, compact with uniform levels or slopes between points where elevations are indicated or between such points and existing grades.

Finish surfaces free from irregular surface changes and as follows:

1. Lawn or Unpaved Areas: Finish areas to receive topsoil to within not more than 0.10 foot above or below required subgrade elevations.

2. Walks: Shape surface of areas under walks to line, grade, and cross-section, with finish surface not more than 0.10 foot above or below required subgrade elevation.

3. Pavements: Shape surface of areas under pavement to line, grade, and cross-section, with finish surface not more than 1/2 inch above or below required subgrade elevation.

4. Grading Surface of Fill under Building Slabs: Grade smooth and even, free of voids, compacted as specified, and to required elevation. Provide final grades within a tolerance of 1/2 inch when tested with a 10-foot straightedge.

B. Compaction

1. Compaction: After grading, compact subgrade surfaces to the depth and indicated percentage of maximum or relative density for each area classification. Compact each layer to required percentage of maximum dry density or relative dry density for each area classification. Do not place backfill or fill material on surfaces that are muddy, frozen, or contain frost or ice. Control soil and fill compaction, providing minimum percentage of density specified for each area classification indicated below. Correct improperly compacted areas or lifts as directed by Engineer if soil density tests indicate inadequate compaction.

2. Method: Specified Density Method shall be the method of compaction used. Soil shall be compacted within the moisture specification range in accordance with Table 1, unless otherwise specified in detailed plans and specifications. Optimum moisture will be determined by the

AASHTO T 180 (Modified Proctor).

Page | 7

Table 1.

3. Moisture Control: Where subgrade or layer of soil material must be moisture conditioned before compaction, uniformly apply water to surface of subgrade or layer of soil material. Apply water in minimum quantity as necessary to prevent free water from appearing on surface during or subsequent to compaction operations. Remove and replace, or scarify and air dry, soil material that is too wet to permit compaction o specified density. Stockpile or spread soil material that has been removed because it is too wet to permit compaction. Assist drying by discing, harrowing, or pulverizing until moisture content is reduced to a satisfactory value.

13. ROAD SUBGRADE PREP

1. The excavation and embankments for the roadway, intersections, and entrances shall be finished to smooth and uniform surfaces. Materials shall not be wasted without written permission. Grading operations shall be conducted so that material outside of the limits of slopes will not be disturbed.

Unsuitable material encountered in the subgrade or slopes shall be removed and the area backfilled to the finished graded section with approved material. Unsuitable material shall be disposed of at locations acceptable to the Engineer.

2. The subgrade shall be finished to within minus 0.08 feet to plus 0.02 feet from the design grade and typical section shown in the plans and to within ± 0.5% of the typical section cross slope. The quarter crown within any 12 foot transverse length shall not exceed 0.04 feet above or below a straight edge, string line, or by other suitable equipment measuring between the crown and edge of roadway. The centerline shall be finished to a transverse distance within ± 0.25 feet of the plans shown location of centerline.

14. MATERIALS TESTING

A. Soil Tests

1. AASHTO T 180 (Modified Proctor): The Contractor shall provide the Engineer with the results of the modified proctor soil compaction test, as determined by AASHTO T-180. If no locations are

Soil Type

Density Specification

(Percent of Maximum

Dry Density)

Moisture Specification

(Percent of Optimum

Moisture)

Cohesive 92% or Greater -3% to +8%

Non-cohesive 95% or Greater Workable

Page | 8 indicated on the plans, proctor test results shall be provided for locations determined by the

Engineer. Should it become apparent during construction that the soil types encountered are significantly different from the initial samples, additional sampling and testing may be required.

If requested by the Engineer, the Contractor shall provide the Engineer with no less than 25 pounds of each sample appropriately labeled with the project title, the location from which the sample was obtained, the date of sample collection, and name of the person who collected the sample, and the name of the person or firm who conducted with compaction test. A City Inspector shall be present during sample collection.

2. AASHTO T 238 (In-place Nuclear Density): Unless otherwise specified in the Detailed Specifications, field density tests, will be performed by the Engineer. The field density shall be measured with a nuclear density machine in accordance with SD DOT Materials Manual SD114 (AASHTO T 238).

Contractor will be required to provide a prepared surface in the embankment shaped to facilitate testing at locations requested by the Engineer.

When embankment contains over 40% by weight of durable material passing an 8 inch square opening and retained on a 3/4 inch sieve, specified density requirements will be waived. Material retained on a 3/4 inch sieve will be considered durable when, after soaking in water for 24 hours, this retained material cannot readily be broken with the fingers and passed through the sieve. The embankment shall be compacted with sheepsfoot or other approved rollers to the satisfaction of the Engineer. Moisture requirements will be determined in accordance with SD DOT Materials

Manual SD104, except the optimum and field moisture will be determined using material passing a

3/4 inch sieve.

For non-cohesive soil, embankment shall be spread in layers not exceeding an 8 inch loose depth and adequately compacted, with approved vibratory or pneumatic rollers, at the moisture content needed to obtain stability.

3. Proof Rolling: Proof rolling shall be performed prior to placing base course. Equipment shall be a tandem-axle dump truck or tri-axle dump truck with the third axle raised, and shall have a minimum gross weight of 24 tons. Tires shall be properly inflated to the recommended pressure. Rolling operations shall be done in the center of each driving lane at walking speed. Inspection of the subgrade response at the rear axle shall be performed by the Engineer. To achieve passing results, no more than 1 inch of deflection shall be observed, and no cracking or pumping of the subgrade shall be present.

B. Submittals

Test Reports: Submit the following reports directly to Engineer from the testing services, with copy to Contractor:

1. Test reports on borrow material.

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2. Verification of suitability of each footing subgrade material, in accordance with specified requirements.

3. Field reports; in-place soil density tests.

4. Report of actual unconfined compressive strength and/or results of bearing tests of each strata tested.

15. POND CONSTRUCTION DETAILS

A. Embankments and Dikes

1. Embankments and dikes shall be constructed of relatively impervious and stable material, and compacted to at least 90 percent of Standard Proctor Density (ASTM D698 or AASHTO T99);

however, 95 percent of Standard Proctor Density with a moisture content near to 3% wet of optimum is recommended. The compaction and moisture conditions shall be sufficient to limit the seepage through the dike to 1/16 inch per day for all primary cells and shall not exceed 1/8 inch per day for all other cells.

2. All vegetation, roots, and topsoil shall be removed from the area upon which the embankment is to be placed. The embankment material must not contain any organic material, debris, frozen material, large clods or stones larger than 6 inches in diameter. Topsoil shall only be used in the outer portions of the embankment and blended with the other soils. Pond bottom and embankment seals consisting of soils, bentonite, or synthetic liners may be considered provided the permeability, durability, and integrity of the proposed material can be satisfactorily demonstrated for the anticipated conditions.

3. The minimum embankment top width shall be eight (8) feet to permit access of maintenance vehicles. Lesser top widths could be considered for very small installations, one acre or less.

4. Interior embankment slopes should not be steeper than three horizontal to one vertical (3:1) and not be flatter than six horizontal to one vertical (6:1) on the inside. Flatter slopes are sometimes specified for larger installations because of wave action but have the disadvantage of added shallow areas conducive to emergent vegetation and mosquito breeding. The exterior slopes should be three or more horizontal to one vertical for prevention of erosion.

5. Minimum freeboard shall be three (3) feet except for very small installations, one acre or less, where two (2) feet will be permitted.

6. The normal minimum liquid depth in any cell shall not be less than two (2) feet.

7. The embankment exterior shall be covered with at least 4 inches of fertile topsoil.

8. Embankments shall be seeded from the outside toe to the high-water line on the interior slope

Page | 10

9. wherever riprap, soil sterilant, and bank stabilization is not utilized. Low growing and spreading perennial grasses that withstand erosion are most satisfactory. In general, alfalfa, clover and other long-rooted vegetation should not be used, since the roots of this type of plant are apt to impair the water holding efficiency of the dikes. For sediment and erosion control, refer to the

Department Guide, BMPs "Best Management Practices". The County Agricultural Extension Agent or local Conservation District can usually advise as to hardy, locally suited permanent grasses which would be satisfactory for embankment seeding. Prior to filling or prefilling, the newly seeded vegetation shall be well established if submergence and wave action will occur.

10. A method shall be specified which will prevent vegetation growth over the bottom of the ponds and up to the high-water line on the interior embankment slopes. If prefilling is specified before weed growth is established, then soil sterilants may not be necessary up to the prefilled water level.

11. Provisions shall be made for riprapping or bank stabilization of the interior slopes of any cell of five acres or more. Protection for outer embankments (riprap) may be necessary where the dikes are subject to erosion due to severe flooding of an adjacent watercourse. Riprapping or bank stabilization is highly recommended for all cells.

B. Riprap and Bank Stabilization Requirements

1. The riprap or bank stabilization shall be provided on the interior slopes from the toe to the top of the freeboard. It shall be hard and durable and be stable after placement.

2. The riprap should be approximately 6 to 18 inches in diameter.

3. The riprap shall be placed in depths of 8-18 inches depending upon size, location and configuration of cells.

4. Since riprap is usually placed against fine material, a filter of sand with gravel or spalls shall be placed on the embankment slopes prior to riprapping. The depth of the filter material should be at least four (4) inches. Another alternative available is synthetic filter blankets which shall be securely anchored and shall have been satisfactorily demonstrated by prior use to be suitable and durable for such purposes.

16. POND BOTTOM

1. The pond bottom should be as level as possible at all points. Finished elevations should not vary more than three inches from the average elevation of the bottom.

2. Prior to scarifying, all topsoil shall be removed. In cut areas, the bottom shall then be scarified to a depth of 12 inches and cleared of vegetation and debris. Organic material thus removed shall not be used in the dike core construction. However, suitable topsoil relatively free of debris may

Page | 11

3. be used as cover material on the outer slopes of the embankment. If preliminary tests have determined that the soils exposed on the pond bottom are capable of meeting the allowable seepage limits, a minimum of six (6) inches of the scarified soil shall be removed, the remaining scarified soil shall be brought to the proper moisture content and compacted to the specified density, and then the removed soil shall be uniformly spread and compacted, at the proper moisture content, as specified.

4. Soil boring information and results of percolation, porosity or permeability tests to determine the characteristics of surface soil and subsoil shall be compared to visual observations at the select pond sites and any discrepancies brought to the attention of the town’s engineer immediately.

Gravel, gypsum and limestone areas must be avoided.

5. The ability to maintain a satisfactory water level in the ponds is one of the most important aspects of design. Removal of porous topsoil and proper compaction of subsoil improves the water holding characteristics of the bottom. Porous areas within 2 feet of the finished pond floor, such as gravel or sand pockets, shall be removed and replaced with well-compacted clay or other suitable material. Where excessive percolation is anticipated, sealing of the bottom with a clay blanket, bentonite, synthetic liners or other sealing material may be required to achieve a percolation rate not to exceed 1/16 inch per day for all primary cells and shall not exceed 1/8 inch per day for all other cells. The proposed seal should be substantiated by a soils engineering report.

6. Clay for liners shall be placed and compacted in at least two (2) lifts, the depth of any lift shall not exceed 8 inches.

7. The suitability of sealing the pond with bentonite will depend on the type of soil and conditions encountered in the field. Application rates for an effective seal can be determined by the use of a particle size analysis and the Atterberg limits tests. The application rate shall be specified in terms of pounds per square foot. The blanket application method is preferred to the soil-bentonite mix application because it provides a complete seal using approximately one-half of the amount for a mix application. A minimum of one to two inches (1-2) of Bentonite may be required to make a complete seal.

Bentonite should be applied only on well packed and smooth surfaces. After bentonite has been applied, at least two (2) inches of soil should be placed on top of the bentonite and moderately packed to ensure that bentonite material will remain in place until the pond is put into operation.

8. Prior to putting the ponds into operation, percolation tests shall be conducted and submitted to the engineer. Suggested methods for conducting percolation tests are double ring infiltrometer, laboratory permeability tests on thin wall tube samples, with the neutron method supplement weighing lysimeters or seepage tests on the entire pond in which the pond is filled and the water level and pan evaporation rate are monitored daily. If tests indicate seepage limits are exceeded, the seal shall be modified and retested until it meets those limits as required.

8. Prefilling the pond should be considered in order to protect the liner, to prevent weed growth, to reduce odor, and to maintain moisture content of the seal.

Page | 12

17. INFLUENT LINES

1. Any generally accepted pipe material for underground sewer construction will be given consideration for the influent line to the pond. The pipe material selected should be adapted to local conditions. Special consideration must be given to the character of the wastes, possibility of septicity, corrosion, exceptionally heavy external loadings, abrasion, the necessity of reducing the number of joints, soft foundations and similar problems. Surcharging of gravity flow sewers upstream from the inlet manhole is not permitted.

2. A manhole shall be installed at the terminus of the gravity line or force main to the primary cell and located as close to the dike as topography permits. The invert of this manhole should be at least six (6) inches above the maximum operating level of the primary cell to provide sufficient hydraulic head without surcharging the manhole. Flow distribution structures shall be designed to effectively split hydraulic and organic loads equally to multiple primary cells.

3. Influent lines shall be located along the bottom of the primary cell and shall be securely anchored to the bottom of the pond so that the invert elevation is near the bottom of the pond. This line can be placed at zero grade. The use of an exposed dike to carry the influent line to the discharge point is prohibited, as such a structure will impede circulation and cause localized deposition of sludge. Influent lines shall not be located within or below the seal.

4. Influent piping should be located to minimize short-circuiting within the cell. Each primary cell of a multiple-celled pond operated in parallel shall have a separate inlet, but this does not apply to those cells following the primary cell when series operation alone is used. Influent lines or interconnecting piping to secondary cells of multiple-celled ponds operated in series may consist of pipes through the separating dikes. Influent lines to rectangular ponds should terminate at approximately one-third of the length from the upstream end of the cell and its outlet structure, except that it shall be at approximately the mid-point for cells without an outlet.

5. The end of the influent line shall be provided with a concrete headwall and shall rest on a suitable concrete apron that is at least four (4) feet by four (4) feet. The influent line shall discharge horizontally into a shallow, saucer-shaped depression.

18. CONTROL STRUCTURES

1. Interconnecting piping and overflow piping should be of cast iron, corrugated metal, or other suitable materials of at least eight (8) inches in diameter. Piping shall have capacity to permit transfer of water at a minimum rate of six (6) inches of pond water depth per day at the available head.

Page | 13

2. Control structures shall be provided for each cell. No discharge structure will be permitted for a single cell installation. The control structure should provide a positive visual means of directing and controlling the flow and be accessible for maintenance and adjustment of controls. The control structure should consist of a manhole or box equipped with multiple-valved pond drawoff lines or an adjustable overflow device so that the liquid level of the pond can be adjusted to permit operation between the minimum and maximum operating levels. At least one drawoff line shall be located at the two (2) foot level. The lowest of the drawoff lines to such structure should be 12 inches off the bottom to control eroding velocities and avoid pickup of bottom deposits. Erosion protection should be provided at the inlet and discharge end of the piping. The overflow from the pond during ice-free periods should be taken near, but below, the water surface to release the best effluent and ensure retention of floating solids. A locking device should be provided to prevent unauthorized access to and use of the level control facilities. The outlet structure should be located to minimize short-circuiting within the cell, if possible, on the windward side. Consideration must be given in the design of all structures to protect against freezing or ice damage under winter conditions.

3. Interconnecting piping for multiple unit installations operated in series should be valved or provided with other arrangements to regulate flow between structures and permit flexible depth control. Interconnecting piping to secondary cells should discharge horizontally near the pond bottom to minimize the need for erosion control measures and should be located as near the dividing dike as construction permits. Consideration must be given in the design of all piping to protect against freezing or ice damage under winter conditions. Interconnecting piping shall be provided with splash pads. Anti-seep collars may be necessary on pipes penetrating the dikes, to discourage seepage and scouring.

4. The outlet end of the discharge pipe should be screened to prevent the entrance of wildlife.

19. MISCELLANEOUS

A. Access Roads

An all-weather access road conditions to the pond site shall be maintained to carry out the routine inspections and maintenance which are required year-round on even the smallest installations. The existing easement will permit light shaping and gravel surfacing for a ten foot roadway. Such minimums may only be satisfactory where the drainage is good and the distance from a maintained roadway is less than one-half mile. Minimum access fulfilling these requirements should be provided in all cases.

B. Flow Measurement

Provisions for flow measurement devices shall be provided at the inlet and outlet of controlled-discharge systems. Flow measurement devices shall be capable of measuring the

Page | 14 maximum anticipated flows. Recording equipment shall be protected from the weather and flow conditions.

C. Depth Measurement

Pond depth indicators shall be provided. Due to ice conditions, a calibrated, inclined concrete section anchored into the dike slope is the most desirable. The outlet structure of each cell may also be utilized if properly and permanently calibrated.