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Licensed for the sole use of the purchaser.See license agreement penalties for distribution. CGA G-'1.8-2017 COMPRESSED GAS ASSOCIATION INC. PAGE 7 7.4.2 Removal as slurry Most carbide lime users are equipped to receive lime in bulk form as a water-based slurry. While use require- ments for slurry concentration can vary, carbide lime slurry is typically shipped at a solids concentration of 30% to 40%.To lessen transportation costs,the solids content of the slurry should be maximized. Removal of lime paste from a pond in slurry form can be accomplished using several methods. Screening of lime may be necessary to protect equipment and ensure consistent lime quality. Lime slurry methods include: • Floating barge/pump—This method uses a pump mounted on a floating barge. An operator on the barge uses the pump in recirculation mode to mix lime to slurry form and then transfers the slurried lime to a storage tank or transport vehicle; • Remote or manually operated dredge—Both models are usually equipped with submerged cutting head(s) to grind harder, carbonated lime and homogenize paste.An on-board pump conveys slurry to a storage tank via a floating transfer hose; and • Direct slurry pumping from pond side—This method uses existing water in a pond or water from an external source. A pump placed on the side of the pond can be used to slurry lime and transfer it into a storage tank or transport vehicle. A common method for maximizing solids content is to pump the slurry into a decant tank system. In a decant system, a series of tanks with sequential overflow lines are used to concentrate and store slurried lime from the pond. With time, the lime solids settle to the bottom of the tank and excess water overflows to the next tank in the series. Excess decanted water can be used for pond slurry makeup or reused in acetylene generation. The size and number of tanks used varies and depends upon lime production needs and customer demand, 8 Lime pond closure procedures Generally, it is recommended that all marketable lime be removed from the pond before conducting final closure activities. CGA recommends a four-phased approach to the closure of lime ponds to facilitate a cost-effective and efficient closure program in compliance with all applicable regulations. The phases involve the following: a) Phase I—Site characterization and regulatory review; b) Phase II—Work plan development; c) Phase III—Work plan implementation/field closure activities; and d) Phase IV—Postclosure. Phase I is designed to assist the owner/operator of the lime pond to collect pertinent and relevant physical, chemical, geotechnical, and regulatory information.This information is used to develop and implement an accu- rate work plan (Phase II), to complete the field activities (Phase III), and bring the facility to final regulatory closure (Phase IV). The owner/operator of the lime pond may choose to contract the services of a professional consultant to assist in the completion of Phase I, Phase II,and/or Phase III.The consultant can also assist in preparing the technical bid specification to select a qualified contractor to close the pond in accordance with the work plan and specifi- cations. 8.9 Phase I—Site characterization and regulatory review Phase I of the lime pond closure program is designed to collect the physical, chemical, geotechnical, historical, and regulatory information necessary to develop an accurate lime pond closure work plan and, if appropriate, bid documents. This document licensed for the sole use of the purchaser It may not be shared with any other person or used after the expiration date without the express written permission of the CGA_ Any unauthorized use. reproduction, distribution,or modification of this printed page will result in a$5,000 liquidated damages fee plus loss of access to CGA publications for one year for your company.