Section 157 — Soil Erosion and Sediment Control

Description

157.01This work consists of providing, constructing, maintaining, and removing soil erosion and sediment control measures to eliminate or minimize pollutants in stormwater discharges from the project.

Material

157.02Conform to the followin g Subsections: Fiber rolls 713.12 Filter rock 705.08 Floating turbidity curtains 713.21 General purpose tackifier 713.11(a) Geote xtile 714.01 Gravel bags 713.13 Mulch 713.05 Nonloadbearing concrete masonry units 725.07(c) Plastic lining 713.22 Prefabricated filter insert 713.20 Rock for riprap 705.02 Rock mulch 705.07 Rolled erosion control products 713.17 Sandbags 713.14 Sediment filter bags 713.19 Seed 713.04 Silt fence 713.16 Soil and soil- aggregate materials 704.01 Temporary culvert pipe 713.15 Temporary plastic fence 710.08 Turf reinforcement mats 713.18 Water for vegetation 725.01(b)

Construction Requirements

157.03Qualifications. Provide personnel with experience providing erosion and sediment control and pollution prevention. At least 14 days before starting earth disturbing work, submit a résumé for each individual describing at least 5 years ’ experience providing erosion and sediment control and pollution prevention on highway or road construction projects for approval . Include certifications in those states where applicable.

157.04General . Provide and construct permanent and temporary soil erosion and sediment control measures according to the plans, contract permits, Section 107, and this Section. Contract permits amend the requirements of this Section. Do not modify the type, size, or location of measures or practices without approval. Manage SWPPP documentation and reporting requirements according to contract permits. An alternate erosion and sediment control plan or SWPPP, with necessary permits, may be submitted for approval according to Subsection 104.06. S ubmit alternate erosion and sediment control proposals at least 30 days before their intended use. If soil erosion and sediment control measures are not functioning as intended, take corrective action to eliminate or minimize pollutants in stormwater discharges from the project.

157.05Controls and Limitations on Work . Mark clearing limits and construct sediment perimeter control measures before ground disturbing activities. Limit the combined grubbing and grading operations areas to 5 acres of exposed soil at one time. Construct and implement soil erosion and sediment control measures as follows:

(a)Construct temporary measures in incremental stages as construction proceeds.

(b)Following each day’s grading operations, shape earthwork to minimize and control soil erosion and sediment transport from stormwater runoff. (c) Divert runoff around exposed soils.

(d)Stabilize areas of exposed soil where construction activities have permanently ceased or will be temporarily inactive for the next 14 days. Complete the installatio n of stabilization measures as soon as practical, but no later than 14 days since last disturbance. (e) Construct outlet protection as soon as culverts or other structures are complete.

(f)Construct and maintain soil erosion and sediment controls on and around soil stockpiles.

(g)Maintain stabilized construction exits to minimize tracking of soil onto existing roads.

157.06Filter Barriers. Construct silt fence, berms, and fiber rolls to reduce the velocity of runoff to allow sediment to settle. 157.07 Sediment Retention Structures. Construct sediment retention structures of the following types:

(a)Temporary sediment traps. Construct temporary sediment traps to detain runoff from disturbed areas and settle out sediment. Provide outlet protection. (b) Sediment basins. Construct sediment basins to store runoff and settle out sediment for large drainage areas. Excavate and construct sediment basins according to Section 204. Construct riser pipes according to Section 602. Provide outlet protection.

157.08Outlet Protection . Construct riprap aprons or basins to reduce water velocity and prevent scour at the outlet of permanent and temporary erosion and sediment control measures. Construct riprap accor ding to Section 251.

157.09Water Crossings. Construct temporary culvert pipe or bridge at temporary crossings where construction vehicles cross a live waterway according to Section 107.

157.10Temporary Stormwater Diversions. Construct temporary channels, temporary culverts, earth berms, or sandbags to divert stormwater around disturbed areas and slopes. Stabilize channels according to Subsection 157.11. Provide outlet protection.

157.11Channel and Slope Protection and Stabilization. Use the following:

(a)Plastic lining . Use plastic lining to protect underlying soil from erosion. Place the plastic lining loosely on a smooth soil surface free of projection s or depressions that may cause the liner to puncture or tear. Anchor the lining in place using riprap, gravel bags, or sandbags. If plastic liner is being used for a temporary stormwater diversion channel, place seams perpendicular to the direction of stormwater flow and overlap at least 18 inches.

(b)Riprap. Construct riprap according to Section 251.

(c)Check dams. Construct riprap, filter rock, gravel bags, sandbags, and fiber rolls for check dams to reduce the velocity of runoff in ditches and swales.

(d)Rolled erosion control products. Use rolled erosion control products before or after temporary or permanent seeding. Install according to Section 629.

(e)Temporary slope drains. Use drain pipe, riprap, or plastic lined channel for temporary slope drains. Channel water into the slope drain with an earth berm, gravel bag, or sandbag headwall constructed at the top of a cut or fill. Anchor slope drains to the slope. Provide outlet protection.

(f)Floati ng turbidity curtains. Install floating turbidity curtains within a body of water to minimize the migration of silt laden stormwater out of the construction area.

157.12Temporary Soil Stabilization. Control soil erosion on unprotected slopes. Do not impo rt wood chips without approval. Use the following:

(a)Temporary cover. Use mulch, plastic lining, RECP, or tackifier. Apply according to the manufacturer’s recommendations or as approved. (b) Temporary turf establishment. Apply seed and mulch for soil erosion protection at the rates shown in Table 157 -1. Protect and care for seeded areas, including watering, until permanent turf establishment is in place. Table 157-1 Application Rates for Temporary Turf Establishment

Material Application Rate,

pounds/acre Seed 45 Wood fiber or grass straw cellulose fiber mulch 2000(1)

(1)Apply mulch using hydraulic method according to Subsection 625.08(b) . For other mulch products and application methods, use the manufacturer’s rate as approved.

157.13Permanent Soil Stabilization. Control soil erosion on completed permanent slopes. Use the following:

(a)Turf establishment. Apply turf establishment according to Section 625.

(b)Plants , trees, shrubs, vines, groundcovers, and other plants. Plant trees, shrubs, vines, groundcovers, and other plants according to Section 626.

(c)Sod. Place sod of perennial turf -forming grasses according to Section 627.

(d)Rock mulch. Place rock on finished surfaces.

157.14Inspection and Reportin g. Inspect erosion and sediment control measures according to contract permits. If no contract permits apply, inspect at least once every 7 days and within 24 hours of the occurrence of a storm event of 0.25 inch. Within 24 hours after each inspection, submit an inspection report. Include the following:

(a)Date and time of the inspection;

(b)Names and titles of persons making the inspection;

(c)Summary of the inspection;

(d)Weather since the last inspection or since the start of work, if the first inspection. For each storm event, include the starting date and time, duration, precipitation quantity in inches, and whether discharge occurred;

(e)Weather and description of discharges occurring during the inspection;

(f)Locations of discharges or other pollutants from the site;

(g)Locations of erosion and sediment control measures that need maintenance;

(h)Locations of erosion and sediment control measures that failed to operate as designated or proved inadequate for a particular location; (i) Locations where additional erosion and sediment control measures are needed; and

(j)Other necessary corrective actions including act ion taken, locations, dates, and times.

157.15Maintenance and Cleanup . Maintain temporary and permanent erosion and sediment control measures in working condition until final acceptance or the measures are no longer needed. Remove sediment trapped in pe rimeter protection control measures before deposits reach 50 percent of the above ground height. Remove sediment from sediment retention structures when their capacity is reduced to 50 percent of design capacity. Use removed sediment in the work if approved or dispose of it according to Subsection 204.14. Replace erosion and sediment control measures that cannot be maintained and those that are damaged by construction operations. When vegetation coverage meets permit require ments , conforms to Subsection 625.09, and drainage ditches and channels are lined and stabilized , remove and dispose of temporary erosion and sediment control measures according to Subsections 203.05 and 203.07. Restore the ground to its natural or intended condition and provide permanent erosion control measures.

157.16Acceptance . Material for erosion and sediment control measures will be evaluated under Subsections 106.02 and 106.03. Construction, maintenance, and removal of erosion and sediment control measures will be evaluated under Subsections 106.02 and 106.04.

Measurement

157.17Measure the Section 157 pay items listed in the bid schedule according to Subsection 109.02 and the following as applicable: When measuring soil stabilization by the acre, measure on the ground surface. Do not measure replacement items.

Payment

157.18The accepted quantities will be paid at the contract price per unit of measurement for the Section 157 pay items listed in the bid schedule. Payment will be full compensation for the work prescribed in this Section. See Subsection 109.05 . Progress payments for erosion control measures will be paid as follows:

(a)25 percent of the pay item amount will be paid after installation.

(b)An additional 50 percent of the pay item amount will be prorated based on total work completed under this Section. (c) The remaining portion of the pay item amount will be paid after the temporary erosion control measure is removed from the project or at final acceptance.