2012-054 RES AWARDING CONTRACT FOR REHABILITATION OF EAST ELEVATED STORAGE TANK TO CLASSIC PROTECTIVE COATINGS INC

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SSPC-Guide 6 October 1, 2004 5.5.6 Method F-Water and Sediment Analysis for Toxic Metals: Pre-job and post-job assessment of toxic met- als (e.g., lead) in sediment can be useful in determining if proper protection of a water body has been achieved. Pre-job sampling should be accomplished in discrete locations around and beneath the project site to a sediment depth of no more than 6 in (15.6 cm). Samples should be removed at the same locations upon project completion. Sampling of water may or may not provide valuable infor- mation due to the transient nature of the toxic metai (e.g. lead) in fast moving water bodies (sediment analysis may be a more reliable indicator). However, for sedentary bodies of water or if a drinking water intake is located nearby, pre-job and post-job water sampling and analysis may be beneficial. 5.5.7 Method G-Visual Assessment of Site Cleanli- ness: A visual assessment of the cleanliness of the work site and surrounding property is made each day and upon project completion. Pre-existing debris is identified and mapped in advance, or preferably is removed prior to work or as part of the contract. By removing the debris in advance, disputes over the responsibility for clean up are eliminated. By having a visually clean project site before the work begins, it provides another means forverifying the suitability ofthe projectcontrols. For example, the presence of spent abrasives on the ground will indicate that a containment leak or breach has occurred. Under this method, the site and surrounding property are free of accumulations of debris each day and are free of all visible debris upon project completion. 6. Disclaimer 6.1 While every precaution is taken to ensure that all in- formation furnished in SSPC guides is as accurate, complete, and useful as possible, SSPC cannot assume responsibility nor incur any obligation resulting from the use of any materials, coatings, or methods described herein, or of the guide itself. 6.2 This guide does not attempt to address problems concerning safety associated with its use. The user of this specification, as well as the user of all products or practices described herein, is responsible for instituting appropriate health and safety practices and for ensuring compliance with all governmental regulations. 7.2 The OSHA Interim Final Rule on Lead in Construc- tion (29 CFR 1926.62) does not specify air velocities moving through containment, but it states that engineering and work practice controls must be utilized as necessary to reduce airborne exposures. 7.3 The construction industry ventilation standard (29 CFR 1926.57) refers to ANSI Z9.2-1960 with regard to abra- sive blast cleaning. ANSI Z9.2-1960 was revised in 1979 and again in 2001. ANSI Z9.2-1979 in Tabie A2 suggests a down- draft velocity in abrasive blasting rooms of 60 to 100 feet per minute. The 2001 version has removed the technical design data from the standard and instead refers to other resources for this information (described below). ANSI Z9.4-1985 (revised in 1997) addresses ventilation in abrasive blasting rooms. Both the 1985 and 1997 versions suggest provision of a downdraft ranging from 60 to 90 feet per minute (the larger the floor area, the lower the air flow recom- mendation), or across draftof 100 feet per minute when remov- ing coatings containing toxic metais by dry abrasive blasting. Both ANSI Z9.2-2001 and ANSI Z9.4-1997 refer to "In- dustrial Ventilation, A Manual of Recommended Practice" published by the American Conference of Governmental Industrial Hygienists (ACGIH) as the definitive resource in the area of industrial ventilation. Figure VS-80-01, Abrasive Blasting Room, of"Industrial Ventilation" suggests adown draft velocity of 50 to 100 feet per minute (with a typical choice of 80 feet per minute) and a cross draft velocity of 100 feet per minute. These recommendations are for operator visibility and to control the escape of contaminants into adjacent work areas. SSPC recognizes that fixed abrasive blast rooms are not the same as field containment structures, and is making no representations regarding the suitability of the velocities (whethertoo much ortoo little). Forexample, Federal Highway Administration research involving air movement inside contain- ment when removing lead paint by abrasive biast cleaning Research Report Number RD-94-100) found no significant differences in worker lead exposures at cross-draft veloci- ties of 70 to 300 feet per minute. (The abrasives involved in the study were steel grit and mineral sand.) The blast room information is presented in these Notes due to the link to ANSI Z9.2 that is provided through 29 CFR 1926.57, and because it may provide information that could be beneficial to some users of the guide. 7. Notes 7.1 In the preamble to 29 CFR 1926.62, OSHA states (pg 26614) that it believes an exposure reduction factor of 50%will be achievable for mechanical ventilation systems. If feasible engineering controlsdo not reduce the exposure belowthe PEL, administrative controls, good work practices, and effective use of respiratory protective equipment are needed in addition to feasible engineering controls to help control worker exposures to lead and other toxic metals. 7.4 ANSI Z9.2-1979 and 2001 indicates that large solid particles usually cannot be captured by conventional air flow patterns, but that air flow patterns should ensure that hy- gienically significant particle sizes are captured. Hygienically significant particle sizes are defined as those which are less than 10 micrometers in size. It suggests that the larger particle sizes should be aliowed to fall to the floor to be removed by housekeeping practices. As a result, when designing ventila- tion systems for containment, primary consideration should be given to the movement of the hygienically significant particle 9-11