Rodarte Construction Inc Everett Station Parking Expansion

I I1 1. Water-only shaft drilling slurryor water slurry with accepted flocculants may be 2 infiltrated on-site. Flocculants used shall meet the requirements of Section 9- I 3 14.5(1) or shall be chitosan products listed as General Use Level Designation 4 (GULD) on the Washington State Department of Ecology's stormwater treatment 5 technologies webpage for construction treatment. Infiltration is permitted if the I 6 following requirements are met: 7 8 a. Wastewater shall have a pH of 6.5—8.5 prior to discharge. 1 9 10 b. The amount of flocculant added to the slurry shall be kept to the minimum 11 needed to adequately settle out solids. The flocculant shall be thoroughly 12 mixed into the slurry. I 13 14 c. The slurry removed from the shaft shall be contained in a leak proof cell or 15 tank for a minimum of 3 hours. I 16 17 d. The infiltration rate shall be reduced if needed to prevent wastewater from 18 leaving the infiltration location. The infiltration site shall be monitored regularly 19 during infiltration activity. All wastewater dischargedto the ground shall fully I 20 infiltrate and discharges shall stop before the end of each work day. 21 22 e. Drilling spoils and settled sediments remaining in the containment cell or tank I 23 shall be disposed of in accordance with Section 6-19.3(4)F. 24 25 f. Infiltration locations shall be in upland areas at least 150 feet away from I 26 surface waters, wells, on-site sewage systems, aquifer sensitive recharge 27 areas, sole source aquifers, well head protection areas, and shall be marked 28 on the plan sheets before the infiltration activity begins. 29 I30 g. Prior to infiltration, the Contractor shall submit a Shaft Drilling Slurry 31 Wastewater Management and Infiltration Plan as a Type 2 Working Drawing. 32 This Plan shall be kept on-site, adapted if needed to meet the construction I 33 34 requirements, and updated to reflect what is being done in the field. The Working Drawing shall include, at a minimum, the following information: 35 I 36 I. Plan sheet showing the proposed infiltration location and all surface 37 waters, wells, on-site sewage systems, aquifer-sensitive recharge areas, 38 sole source aquifers, and well-head protection areas within 150 feet. 49 I40 ii. The proposed elevation of soil surface receiving the wastewater for 41 infiltration and the anticipated phreatic surface (i.e., saturated soil). 42 I 43 iii. The source of the water used to produce the slurry. 44 45 iv. The estimated total volume of wastewater to be infiltrated. I 46 47 v. The accepted flocculant to be used (if any). 48 I49 vi. The controls or methods used to prevent surface wastewater runoff from 50 leaving the infiltration location. 51 I City of EverettPage AM 75 Amendments Everett Station 80 Stall Parking Expansion June 2019