McCann Construction Enterprises Inc 11/7/2018

I I1 Turbidity curtain materials, installation, and maintenance shall be sufficient to comply with 2 water quality standards. I 3 4 The Contractor shall notify the Engineer 10 days in advance of removing the turbidity 5 curtain. All components of the turbidity curtain shall be removed from the project. 6 I 7 8-01.3(1)C1 Disposal of Dewatering Water 8 This section is revised to read: 9 10 When uncontaminated groundwater is encountered in an excavation on a project it may 11 be infiltrated within vegetated areas of the right of way not designated as Sensitive Areas 12 or incorporated into an existing stormwater conveyance system at a rate that will not 111 13 cause erosion or flooding in any receiving surface water. 14 15 Alternatively, the Contractor may pursue independent disposal and treatment alternatives I 16 that do not use the stormwater conveyance system provided it is in compliance with the 17 applicable WACs and permits. 18 I 19 8-01.3(1)C2 Process Wastewater 20 This section is revised to read: 21 I 22 Wastewater generated on-site as a byproduct of a construction process shall not be 23 discharged to surface waters of the State. Some sources of process wastewater may be 24 infiltrated in accordance with the CSWGP with concurrence from the Engineer. Some 25 sources of process wastewater may be disposed via independent disposal and treatment I26 alternatives in compliance with the applicable WACs and permits. 27 28 8-01.3(1)C3 Shaft Drilling Slurry Wastewater I 29 This section is revised to read: 30 31 Wastewater generated on-site during shaft drilling activity shall be managed and I 32 disposed of in accordance with the requirements below. No shaft drilling slurry 33 wastewater shall be discharged to surface waters of the State. Neither the sediment nor 34 liquid portions of the shaft drilling slurry wastewater shall be contaminated, as detectable I 35 by visible or olfactory indication (e.g., chemical sheen or smell). 36 37 1. Water-only shaft drilling slurry or water slurry with accepted flocculants may be 38 infiltrated on-site. Flocculants used shall meet the requirements of Section 9- 1. 39 14.5(1) or shall be chitosan products listed as General Use Level Designation 40 (GULD) on the Washington State Department of Ecology's stormwater 41 treatment technologies webpage for construction treatment. Infiltration is I 42 permitted if the following requirements are met: 43 44 a. Wastewater shall have a pH of 6.5 — 8.5 prior to discharge. I45 46 b. The amount of flocculant added to the slurry shall be kept to the minimum 47 needed to adequately settle out solids. The flocculant shall be thoroughly I 48 mixed into the slurry. 49 I I