STORMWATER MANAGEMENT FACILITIES SECTION 910 612 SECTION 910 — STORMWATER MANAGEMENT FACILITIES
910.1Description.
This work consists of constructing stormwater management facilities.
910.2Materials.
anti-seep collars .
STORMWATER MANAGEMENT FACILITIES SECTION 910 613 E. Infiltration Trench
910.3Construction.
before starting construction on stormwater management facilities.
Dewater in accordance with Sections 902 and 906.
lifting lugs to lift and transport pre -cast concrete risers. Do not use the top slab to lift the riser structure. Fill space between pipes and the pre -cast ri ser walls with non -shrink grout. The largest allowable dimension for the opening in the riser of connection of the outfall pipe is the outfall pipe diameter plus 4 -inches.
the collars. Use the excavation as the form for the bottom half of the anti -seep collars. Place formwork for the top half of the anti -seep collars.
Construction Details. Use concrete shims to establish grade and alignment of the pipe. Do not use lumber, masonry bricks, or any other non -concrete material for shims. ii. When placing the principal spillway outfall pipe partially or completely in fill, construct the fill embankment 24 -inches above the proposed top of pipe. Excavate the trench once the fill is in place. STORMWATER MANAGEMENT FACILITIES SECTION 910 614 f. Maintain the outlet structure until project completion by removing accumulated sediment and trash, stabilizing eroded areas, maintaining watertight joints, and as determined by the engineer. Dispose of sediment in accordance with Section 106.8.
stumps, roots, brush, boulders, sod, topsoil, and rubbish. Grade all surfaces under the foundation to remove irregularities.
contract.
maintaining the slope required as shown on the plans. Do not allow construction equipment to travel within 2 -feet of the designed bottom of an infiltration basin. Do not stockpile within the bottom footprint area of the infiltration basin. Install silt fence of compost filter logs between stockpiles and the top of bank.
material to the bottom of an infiltration basin. Remove the material by working from the middle of the facility to the outside edges or from 1 side to the other. Limit the amount of ingress and egress points to as few as possible. Upon removal of the last 2 -feet of material, scarify the bottom elevation. Immediately stabilize ingress and egress points when no longer needed in accordance with Section 908.
the infiltration basin bottom elevation. If the engineer allows, deposit the materials unsuitable for use in the dam foundation and embankment on slopes. Otherwise, use excess material meeting the requirements for embankment to construct embankments. Remove excess and unsuitable material. Excavate rock in accordance with Section 202.
Excavate the foundation cutoff trench to a minimum bottom width of 4 -feet before placing the dam embankment. Construct side slopes for the cut -off trench no steeper than 1 to 1.
the contract.
includes:
STORMWATER MANAGEMENT FACILITIES SECTION 910 615 d. removing noxious or invasive plant species listed by the Delaware Department of Agriculture; and
from the stormwater engineer. Do not allow construction equipment to travel within 2 -feet of the infiltration trench bottom area. Do not stockpile within 10 -feet of the infiltration trench area . Install silt fence or compost filter log between stockpiles and the infiltration trench .
2-feet of the designed bottom elevation.
geotextile with a 12 -inch minimum overlap on the trench sides. Provide enough geotextile to completely cover the stone surface with a minimum of 2 -feet overlap. Secure in place using excess infiltration stone or other methods approved by the engineer. Remove excess geotextile covering the stone surface after a satisfactory stand of permanent vegetation establishes itself, as determined by the enginee r, and with concurrence of the stormwater engineer.
of 3/8 -inch diameter holes evenly spaced around the pipe and 6 -inches on center vertically. Place a removable cap on the top and place an 18 -inch length of rebar through the pipe from side to side and secure on the bottom to serve as an anchoring system. Extend the inspection port from the bottom of the trench to 1 -foot above the top stone elevation.
caps on both ends.
and
equipment to travel within 2 -feet of the designed bottom of the bioretention area. Do not stockpile on or within 10 -feet of the bioretention area . Install silt fence or compost filter log between stockpiles and the infiltration trench .
contract. STORMWATER MANAGEMENT FACILITIES SECTION 910 616 2. Excavate to the design subgrade elevation and scarify. Do not allow construction equipment to travel within 2 -feet of the designed bottom elevation.
diameter holes, evenly spaced around the pipe and 6 -inches on center vertically. Wrap perforated pipe with a metal screen with openings no bigger than 1/2 -inch and no smaller than 3/8 -inch. Place a removable cap on the top and place an 18 -inch length of rebar through the pipe from side to side and secure on the bottom to serve as an an choring system. Extend the inspection port from the bottom of the trench to 1 -foot above the top biosoil mix elevation.
holes, evenly spaced around the pipe and 6-inches on center vertically in accordance with the contract . Wrap perforated pipe with a metal screen with openings no bigger than 1/2 -inch and no smaller than 3/8 -inch. There are no perforations in the cleanout pipe.
mix.
stormwater engineer. Do not allow construction equipment to travel within 2 -feet of the channel bottom areas. Do not stockpile within 10 -feet of the bioswale area.
2-feet of the designed bottom elevation.
Place the geotextile with a 12 -inch minimum overlap on the trench sides. Provide enough geotextile to completely cover the stone surface with a minimum of 2 -feet overlap. Secure in place using excess infiltration stone or other methods approved by the engineer. Remove excess geotextile covering the stone surface after a satisfactory stand of permanent STORMWATER MANAGEMENT FACILITIES SECTION 910 617 vegetation establishes itself, as determined by the engineer, and with concurrence of the Stormwater Engineer.
BMP approval, in accordance with DNREC regulations. All stormwater BMPs must be approved by the Department prior to Final Acceptance.
910.4Method of Measurement.
pond in accordance with Section 202.4.
910.5Basis of Payment.
Price and payment will constitute full compensation for subgrade preparation and providing and placing all materials .
Price and payment will constitute full compensation for stripping, excavating, hauling, placing, and compacting borrow material.
each or lump sum . Price and payment will constitute full compensation for excavating, dewatering, ground preparation, providing and placing all materials, placing and curing PCC, and welding. STORMWATER MANAGEMENT FACILITIES SECTION 910 618 D. The Department will pay the quantity of stormwater management ponds at the contract unit price per cubic yard. Price and payment will constitute full compensation for:
yard. Price and payment will constitute full compensation for :
yard . Price and payment will constitute full compensation for :
payment will constitute full compensation for preparing the subgrade and providing and placing material.
will constitute full compensation for :
STORMWATER MANAGEMENT FACILITIES SECTION 910 619 a. Stone check dam in accordance with Section 907 .
post construction verification.
ponds prior to final acceptance. ITEM DESCRIPTION UNIT 910001 INFILTRATION STONE, NO.3 CY 910002 INFILTRATION STONE, NO.8 CY 910003 INFILTRATION STONE, NO.57 CY 910004 CLAY BORROW, CUT-OFF TRENCH CY 910005 CLAY BORROW, POND LINER CY 910006 OUTLET STRUCTURE EACH 910007 OUTLET STRUCTURE LS 910008 STORMWATER MANAGEMENT POND CY 910009 INFILTRATION TRENCH CY 910010 BIORETENTION AREA CY 910011 BIOSOIL MIX CY 910012 BIOSWALE CY
PLANTINGS SECTION 911 620 SECTION 911 — PLANTINGS
911.1Description.
This work consists of providing and planting specified plants, shrubs, and trees and the replacement and cultural care of the material.
911.2Materials.
911.2.1 Plant Material.
variety. The plants shall have a normal habit of growth with well -developed branch systems and vigorous root systems. Provide sound, healthy, and vigorous plants, free from defects, disfiguration, injury, disease of any kind, insect eggs, borers, and any infestation. The plants shall have been growing under similar climatic conditions to those of the locality of the project for at least 2 years before planting. Prov ide plant material grown in a soil similar to the area where the plants are designed to be installed . Do not provide plants grown in a muck type soil or other foreign type.
requirements. Provide freshly dug plants. The Department will not accept heeled -in or cold storage plants with the exception of plant material delivered before planting as outlined in
Provide plants conforming to all sizes and measurements specified in the plant list provided with the contract. The Department will not accept plants that do not have a normal balance between height and spread. When the contract does not contain any requir ement or exact measurement, provide plants normal for the species and variety as listed in "American Standard for Nursery Stock" (ANSI Z60.1). Match plants as closely as possible where the contract requires symmetry. Measure plants for height and spread with the branches in the normal position. Measure the trunk diameter of all trees up to and including 4 -inches in diameter sizes at a point 6 -inches above the ground. Measure from 12 -inches above the ground level for larger sizes. If the tree branches are not in accordance with the required height, prune the lower branches, without leaving unsightly scars and damaging the trunk to ob tain the correct height. Do not prune branches for this effect before delivery to the site unless approved. The contractor may use plants larger in size than specified. For larger plants, provide with an earth ball or root spread proportionate to the incre ased size.
Provide certificates of inspection of plant materials required by federal, state, or other authorities with the shipment of plants. Provide complete information as to the location of all plants intended to supply and use. The Department reserves the right to inspect, tag, and approve all plants at the source of supply. This inspection and tagging shall not in any way eliminate the right of rejection at the project site. The engineer will inspect and approve plants before planting. The engineer may reject pl ants placed without prior inspection. Protect the plant materials according to best horticultural practices while in transit in to prevent drying or possible desiccation of plant tissue.