Granite Construction Company 5/1/2018

1 liquid portions of the shaft drilling slurry wastewater shall be contaminated, as 2 detectable by visible or olfactory indication (e.g., chemical sheen or smell). I 3 4 1. Water-only shaft drilling slurry or water slurry with approved flocculants may be 5 infiltrated on-site. Flocculants used shall meet the requirements of Section 9- 6 14.5(1) or shall be chitosan products listed as General Use Level Designation 7 (GULD) on the Washington State Department of Ecology's stormwater 8 treatment technologies webpage for construction treatment. Infiltration is I 9 permitted if the following requirements are met: 10 11 a. Wastewater shall have a pH of 6.5— 8.5 prior to discharge. I 12 13 b. The amount of flocculant added to the slurry shall be kept to the minimum 14 needed to adequately settle out solids. The flocculant shall be thoroughly 15 mixed into the slurry. I 16 17 c. The slurry removed from the shaft shall be contained in a leak proof cell or 18 tank for a minimum of 3 hours. I 19 20 d. The infiltration rate shall be reduced if needed to prevent wastewater from 21 leaving the infiltration location. The infiltration site shall be monitored I 22 regularly during infiltration activity. All wastewater discharged to the 23 ground shall fully infiltrate and discharges shall stop before the end of 24 each work day. ■ 25 i26 e. Drilling spoils and settled sediments remaining in the containment cell or 27 tank shall be disposed of in accordance with Section 6-19.3(4)F. I 28 29 f. Infiltration locations shall be in upland areas at least 150 feet away from 30 surface waters, wells, on-site sewage systems, aquifer sensitive recharge 31 areas, sole source aquifers, well head protection areas, and shall be I 32 marked on the plan sheets before the infiltration activity begins. 33 34 g. Prior to infiltration, the Contractor shall submit a Shaft Drilling Slurry I 35 Wastewater Management and Infiltration Plan as a Type 2 Working 36 Drawing. This Plan shall be kept on-site, adapted if needed to meet the 37 construction requirements, and updated to reflect what is being done in I 38 the field. The Working Drawing shall include, at a minimum, the following 39 information: 40 I 41 i. Plan sheet showing the proposed infiltration location and all surface 42 waters, wells, on-site sewage systems, aquifer-sensitive recharge 43 areas, sole source aquifers, and well-head protection areas within 1 44 150 feet. 45 46 ii. The proposed elevation of soil surface receiving the wastewater for 47 infiltration and the anticipated phreatic surface (i.e., saturated soil). I 48 49 iii. The source of the water used to produce the slurry. 50 I 51 iv. The estimated total volume of wastewater to be infiltrated. 52 53 v. The approved flocculant to be used (if any). 1 54 HOT MIX ASPHALT OVERLAY-2018 PAGE 29 OF 53 March 6,2018 I WORK ORDER#3667 AMENDMENTS TO STANDARD PROVISIONS