SOW_Revision_1 _Acid_Washing_Water_Well_Degasifiers _2014-09-18.docx

Statement of Work Revised 19 Sep 2014 F4D3D94216A001 Acid Wash Water Well Degasifers

Background: Vandenberg AFB (VAFB) utilizes two degasifiers/air strippers for the primary use of hydrogen sulfide removal from four (4) source wells. Each degasifier services two (2) wells. As a secondary treatment technique, the units also pull out iron and manganese from the source water. VAFB typically operates two (2) wells at a time, but will run three (3) at time if needed.

Technical Information:

Each tank has a volume of ~1,500 cubic ft. where packed media is present:

Flow rates for each well:

*Degasifier #1: 705 gpm - 1215 gpm *Degasifier #2: 650 gpm - 660 gpm

Detected range for iron (Total) at well field, 2013: 110-440 ppb

Detected range for manganese (Total) at the well field, 2013: 43-73 ppb

Detected range for total dissolved solids (TDS) at the well field, 2013: 420-520 ppm

Description of Services: Two water well degasifiers towers located at the Barka Slough Area are in need of an acid washing. Contractor will supply chemicals and equipment necessary to acid wash and remove fouling of both degasifiers - one at Facility 22406 and the other at Facility 22408.

Degasifier/Scrubber tank towers have an approximate capacity of 25,000 gallons. Each is 25 feet tall and has a diameter of 12 feet. There is no 120 volt single phase power source on site so contractor will have to furnish its own generator.

After washing the media in the degasifier units the solution needs to be tested. Provided the solution meets a non-hazardous level (see below), a government supplied vacuum truck will be made available to collect and/or haul the diluted acid washed solution resulting from the tank washing. If the solution is considered hazardous, the contractor shall provide their own vehicle and shall be responsible for disposal at an alternate off-site location.

Definition of Hazardous: RCRA (Resource Conservation and Recovery Act) compliance, defines waste as hazardous if it meets certain criteria. To qualify as hazardous or RCRA waste, a substance must first be a solid waste. It must then fit the EPA's definition of a "listed" or "characteristic" waste. The Code of Federal Regulations Title 40, Part 261 defines and lists the various RCRA wastes.

Attachment 1