611TREATMENT OF EXISTING FIELD TILE SYSTEMS

610.09 Basis of Payment. Inlet boxes, complete in place, will be paid for at

the contract unit price per each for TYPE E INLET BOX, STANDARD 610001; TYPE F INLET BOX, STANDARD 610001; or TYPE G INLET BOX, STANDARD 610001. Pipe drains will be measured and paid for according to Section 601. End sections will be measured and paid for according to Section 542. Thrust blocks will be paid for at the contract unit price per each for CONCRETE THRUST BLOCKS. The portland cement concrete slab will not be paid for separately but shall be considered as included in the cost of the inlet box. Shoulder curb will be measured and paid for according to Section 661 or Section 662. SECTION 611. TREATMENT OF EXISTING FIELD TILE SYSTEMS

611.01 Description. This work shall consist of locating and treating existing

field tile systems within the limits of the right-of-way. CONSTRUCTION REQUIREMENTS

611.02 Locating Existing Field Tile. Existing field tile in those areas where

they are reported or suspected to exist shall be located by constructing an exploration trench according to Section 213.

611.03 Existing Field Tile Intercepted by Backslopes. Existing field tile

which are intercepted by the backslopes of the roadway after the ditches have been cut shall have the upstream ends tightly sealed with Class SI concrete or brick and mortar. If specified on the plans, the existing field tile within the limits of the pavement and paved shoulders shall be removed or crushed. Removing or crushing existing field tile shall be accomplished by constructing exploration trench along the line of the tile. All trenches cut for the purpose of removing or crushing existing tile within the limits of 2 ft (600 mm) outside the proposed pavement and paved shoulders shall be backfilled to the existing ground line in fill sections and to the elevation of the earth subgrade in cut sections with trench backfill according to Section 208 and compacted according to Article 550.07. Pipe drains, according to the applicable portions of Section 601, shall be used for the terminal 10 ft (3 m) of the existing field tile where it is outletted into the roadway ditch. The pipe drain shall be a single length section of a diameter equal to the diameter of the existing field tile plus 2 in. (50 mm), but not less than 6 in. (150 mm). Pipe drains outletting into a roadway ditch shall have a concrete headwall constructed at the outlet end according to the details shown on the plans. The Treatment of Existing Field Tile Systems Art. 611.07 headwall shall be constructed of Class SI concrete according to the applicable portion of Section 503.

611.04 Field Tile Not Intercepted by Backslopes. Storm sewer shall be

used to replace existing field tile within the right-of-way at locations where the existing tile crosses under the roadway and below the roadway ditches, and shall be constructed according to Section 550. Storm sewer protected shall be used to replace existing field tile within the right- of-way at locations where the existing tile crosses under the roadway and below the roadway ditch. The kinds of material permitted for storm sewer protected shall be Class A according to Article 550.03. Additional protection shall be provided for the storm sewer at roadway ditches by constructing a concrete slab or paved ditch section over the pipe according to the details shown on the plans. The concrete slab shall be used whenever the cover over the slab at the bottom of the ditch is 4 in. (100 mm) or more. The paved ditch section shall be used when the cover is less than 4 in. (100 mm). The concrete slab and paved ditch section shall be constructed of Class SI concrete according to the applicable portions of Section 503. Storm sewer (special) shall be used to replace existing field tile within the right- of-way at locations where the existing tile does not cross under the roadway and is not outlet into the roadway ditch. The kinds of material permitted for storm sewer (special) shall be according to Article 550.03 for storm sewers, Type 2. Storm sewer (special) shall be constructed according to Section 550, except that in lieu of the sand bedding the pipe may be installed according to Article 601.03 and joints between pipe sections shall not be sealed. At locations where storm sewer (special) is outletted into a headwall according to

Article 601 — 05 for pipe drains shall be constructed at the outlet end.