2602.01 DESCRIPTION.
This work shall consist of temporary control measures for all projects, to control water pollution caused by soil erosion. Additional measures are described in Section 2601, Erosion Control.

Projects that are regulated by the requirements of Iowa DNR National Pollutant Discharge Elimination System (NPDES), General Permit No. 2, for Storm Water Discharge Associated with Industrial Activity for Construction Activities, will be identified in the contract documents. The Prime Contractor for these projects will be required to complete, sign, and return, along with the signed contract, a certification statement for storm water discharge associated with industrial activity for construction activities. The affected Subcontractors for the project will be required to sign and return an affidavit identifying them as co-permittees with the Contracting Authority prior to starting work.

The temporary water pollution control work shall be coordinated with permanent erosion control work to ensure economical, effective, and continuous erosion control throughout the construction and post construction period.

2602.02 MATERIALS.
Materials shall be in accordance with Division 41.

2602.03 CONSTRUCTION.
At the preconstruction conference or prior to the start of construction, the Contractor shall submit for acceptance work plans and schedules for accomplishment of temporary and permanent erosion control. The Contractor shall also submit for acceptance the proposed method of erosion control on haul roads and borrow pits and the plan for the removal of excess materials from the project. Work shall not be started until the erosion control schedules and methods of operations have been accepted by the Engineer. All operations shall be scheduled and performed so erosion control features are placed in accordance with the approved work plan.

The Contractor shall provide immediate, permanent or temporary water pollution control measures to prevent contamination of adjacent watercourses and property. This work may involve construction of silt ditches, silt dikes, silt basins, and slope drains, and use of temporary mulches, mats, seeding, or other control devices or methods, as necessary to control erosion. Disturbed areas in which construction activity will not occur for a period of 21 calendar days shall be stabilized no later than the 14th calendar day after no construction activity has occurred. Stabilization shall include temporary seeding, permanent seeding, mulching, sod, or other methods approved by the Engineer.

The Contractor shall incorporate all erosion control features into the project at the earliest practicable time, as outlined in the accepted schedule. Water pollution control measures shall be constructed at locations shown in the contract documents and as determined by the Contractor, at locations where conditions develop during construction that were unforeseen during design, or where needed to control water pollution that develops during normal construction practices.

Water pollution control features shall be maintained in appropriate functional condition from initial construction through completion of the project. Where siltation control features have been reduced in capacity by 50% or more, the Contractor shall restore these features to their original condition.

Clean-out of Silt Fence and Clean-out of Silt Fence for Ditch Check includes excavation and disposal of silt material trapped by the silt fence or silt fence for ditch checks. Shaping of the ditch bottom to the original ditch template is incidental to this item. The Contractor shall dispose of the silt material off project unless otherwise approved by the Engineer to a suitable site within the project limits.

The Contractor shall limit clearing and grubbing, excavation, borrow, and embankment operations in progress to an area commensurate with their capability and progress in keeping the finish grading, mulching, seeding, and other pollution control measures current in accordance with the accepted work schedule. The Engineer may suspend operations if the Contractor fails to provide adequate erosion control measures in a timely manner.

In the event of conflict between these requirements and water pollution control laws, rules, or regulations of other Federal, State, or local agencies, the more restrictive laws, rules, or regulations will apply.

Water pollution control for work outside the right-of-way or easement obtained by the Contracting Authority shall be the responsibility of the Contractor.

2602.04 METHOD OF MEASUREMENT.
Water pollution control items will be measured as follows:

A. Silt Ditches.
Silt ditches will be measured to the nearest 0.1 foot (0.1 m).

B. Silt Fence.
Silt fence will be measured to the nearest 0.1 foot (0.1 m).

C. Silt Fence for Ditch Checks.
Silt fence for ditch checks will be measured to the nearest 0.1 foot (0.1 m).

D. Silt Dikes.
Silt dikes will be measured to the nearest 0.1 foot (0.1 m).

E. Silt Basins.
Silt basins will be measured by count for each silt basin.

F. Removal of Silt Fence.
Silt fence which has been properly removed will be measured in linear feet (meters) to the nearest foot (0.1 m).

G. Removal of Silt Fence for Ditch Checks.
Silt fence for ditch checks which has been properly removed will be measured in linear feet (meters) to the nearest foot (0.1 m).

H. Removal of Silt Basins.
Material used to fill silt basins will be measured in cubic yards (cubic meters) as Class 10 Excavation in accordance with Article 2102.13.

I. Clean-out of Silt Fence
Clean-out of Silt Fence will be measured in linear feet (meters) to the nearest foot (meter). The quantity for Clean-out of Silt Fence will be the linear feet of silt fence measured for the actual area cleaned.

J. Clean-out of Silt Fence for Ditch Check
Clean-out of Silt Fence for ditch Check will be measured in linear feet (meters) to the nearest foot (meter). The quantity for Clean-out of Silt Fence for Ditch Check will be the quantity of Silt Fence for Ditch Check constructed of each ditch check cleaned.

K. Removal and Reinstallation of Silt Fence.
Silt fence repaired through removal and reinstallation will be measured in linear feet (meters) to the nearest foot (meter).

2602.05 BASIS OF PAYMENT.
Water pollution control items will be paid for as follows:

A. Silt Ditches.
For the length of silt ditches properly constructed, the Contractor will be paid the contract unit price per linear foot (meter).

B. Silt Fence.
For the length of silt fence properly installed, the Contractor will be paid the contract unit price per linear foot (meter).

C. Silt Fence for Ditch Checks.
For the length of silt fence for ditch checks properly installed, the Contractor will be paid the contract unit price per linear foot (meter).

D. Silt Dikes.
For the length of silt dikes properly constructed, the Contractor will be paid the contract unit price per linear foot (meter).

E. Silt Basins.
For each silt basin properly constructed, the Contractor will be paid the contract unit price.

F. Removal of Silt Fence.
For the length of silt fence properly removed, the Contractor will be paid the contract unit price per linear foot (meter).

G. Removal of Silt Fence for Ditch Checks.
For the length of silt fence for ditch checks properly removed, the Contractor will be paid the contract unit price per linear foot (meter).

H. Removal of Silt Basins.
For each silt basin properly filled, the Contractor will be paid the contract unit price per cubic yard (cubic meter) for Class 10 Excavation in accordance with Article 2102.14.

I. Clean-out of silt Fence
For Clean-out of silt Fence the Contractor will be paid the contract unit price per linear foot (meter) of silt fence properly cleaned out.

J. Clean-out of Silt Fence for Ditch Check
For Clean-out of Silt Fence for Ditch Check the Contractor will be paid the contract unit price per linear foot (meter) of silt fence for ditch check properly cleaned out.

K. Removal and Reinstallation of Silt Fence.
Silt fence that must be repaired by removal and reinstallation, through no fault of the Contractor, will be paid at two times the contract unit price for the type of silt fence properly repaired.

When it is necessary for the Contractor to clean out, repair, or reconstruct a silt ditch, dike, or basin, the additional payment will be 100% of the contract unit price for construction of that item. When applicable bid items are not in the contract documents, payment for clean out, repair, or reconstruction will be in accordance with Article 1109.03, B.

If water control measures are required due to the Contractor's negligence, carelessness, or failure to install the controls as a part of the work as scheduled, and are ordered by the Engineer, this work shall be performed by the Contractor at no additional cost.

All water pollution control features are to be in functional condition before final acceptance of the contract.

Payment for construction of water pollution control items shall be full compensation for all labor, equipment and materials necessary to construct the items in accordance with the contract documents.