Document 9J1weGnozw7vkZ5KjY12q3ZDD
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A/C Pipe
Producers Association
Public Affairs Committee International Affairs Committee
J. F. Welch, Vice President
Internal Correspondence
April 27, 1982
DATE
AACPP Trade Releases REF: JFW correspondence, same title, February 12,1982 ACTION REQUIRED: Review for information
Enclosed are two articles published as a result of trade releases made under the
"A/C Advisory" program.
'
The April, 1982 issue of Journal of the American Water Works Association reproduced portions of the recent "A/C Advisory" on field performance of A/C water pipe.
The January 22, 1982 issue of Occupational Health and Safety Letter published the statements of Dr. Murray and Browne (Advisory #3) regarding the lack of association between asbestos fibers and gastrointestinal cancer. This article also resulted in an information request from the Director, Criteria and Standards, Office of Drinking W7ater, Environmental Protection Agency. Staff understands that the Journal of American Water Works Association also will publish parts of an AACPP trade release on the Murray-Browne statement.
If you have any questions, please do not hesitate to call.
JFW/ajb Enclosure
cc: A. Kahn, Esq.
copies to:
Public Affairs Committee
International Affairs Committee
H. Olson R. LeGault B. Cook W. Perrell J. Woods J. Baker T. Dougherty W. McCallie B. Collier
R02PI22601 Chrono
E. van der Rest R. Domer L. Giannitrapani N. Officer P. Hart A. Saoulis R. Jalan V. Pattabhi II. Hudson C. Barton S. Al-Tarkait M. Delcourt J. Cuvelier B. Giboin
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Occupational Health a Safety Letter
Volume 12. No. 2
GERSHON W. FISHBEIN, PUBLISHER
January 22,1982
Main Office 1097 National Press Building Washington, D.C. 20045 o (202) 347-3868
Published twice a month. Rate: $125 per year; $235 in combination with Environmental Health Letter. Checks and orders payable to Environews, Inc., 1097 National Press Bldg., Washington, D.C. 20045
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2 BRITISH SCIENTISTS SAY EVIDENCE FAILS TO LINK ASBESTOS, GI CANCER:
Two British scientists. Dr. Robert Murray and Dr. Kevine Browne, have written that the evidence from animal experiments, occupational exposure and epidemiology "is beginning to point strongly away" from any association between asbestos fibers and an excess mortality from gastrointestinal tumors.
Their findings were reported in The Lancet and were the subject of a news release by the A/C Pipe Producers Association in Arlington, Va. Dr. Murray is a Fellow of the Royal College of Physicians, Glasgow.
They relied on two major recent animal studies. One, conducted by the Institute of Occupational Medicine in Edinburg, "confirmed the absence of asbestos-related gut tumors in a large-scale study in rats monitored for their whole lifespan," they reported. The other reference was to studies now underway with animals by the National Institute of Environmental Health Sciences. On the latter, EPA was quoted as say ing "the initial results did not detect any adverse effects on the test animals from asbestos in the diet."
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> that it will not adhere to the tanks or pumps. The possibility f a power outage or mechanical breakdown makes this method nreliable; the material settles, and starting the stirring inhanism is impossible without emptying the storage vessel r diluting the sludge sufficiently to make a thin liquid. Other isad vantages are the constant power required for stirring, the ost of plant-capacity expansion, and the added power tquirements caused by such expansion. Air-diffusion, with application on farm land, is the latest and lost promising method of handling and disposing of limeoftening sludge that contains magnesium hydroxide. This lethod turns the thixotropic property of this compound into an dvantage; the sludge does not have to be agitated constantly, nly when it is being prepared for transport. The air-diffusion method of sludge liquefaction was develped by L.E. Bultman of the Missouri Cities Water Company, nstallations were made and tested in existing sludge-holding anks at several water treatment plants. From these test nstallations, empirical formulas were developed for air iuantities and grid spacing. Tanks varied from 3 to 15 m (10 to 0 ft) in diameter, with both sloping and flat bottoms. All nstallations did a good job of reliquefying the sludge. The u-ocess was patented, and work began on developing systems or manufacture. The Liberty, Mo., municipal water plant sludge diposal ystem was designed as a prototype for this patented process iy a consulting engineering firm.* The system consists of a lumping station to transfer the sludge blowdown from two olids-contact basins, two 228 000-L (60 000-gal)sludge storage anks with air-diffusion grids, a compressed-air blower, and a Judge hauler.
Sludge blowdown from the solids contact basins is pumped nto the bottom of one of the storage tanks. Supernatant is run >y gravity back to the plant to be processed into finished water. \fter the first tank is filled with sludge, use of the second tank legins. Free water is decanted from the first tank, and the 'wer is run for a few minutes to liquefy the sludge prior to
ling. The sludge can be liquefied with no problem, even r several days' settling. i'he sludge hauler is a large tank truck with flotation tires ihd a vacuum pressure system for both loading and unloading. The sludge is mixed by compressed air during transit and applied by means of a specially designed splash plate. The lime is spread uniformly in a 10.8-m (36-ft) swath at the desired rate.
"Larkin and Assoc., Kansas City. Mo.
Sludge of 46 percent dry solids by weight is routinely applied with this equipment. As more requests come in for this new source of agricultural lime, the city hopes to sell the product to defray fuel costs.
The air-diffusion system can be readily adapted for retro fitting and can easily be tailored to any size water treatment plant. In a new plant designed for future capacity expansion, only the first tanks and the blower are required in the initial installation. The same blower will serve additional tanks as they are brought on line.
Reference
1. Thompson, C.G., & Black. A.P. Magnesium Carbonate: A Recycled Coagulant for Water and Waste Treatment. Trans. 22nd Ann. Conf. on Sanitary Engrg. Univ. of Kansas (Feb. 2.1972).
For adcttfinnal information concrrmn# the air-diffusion mrf hod. contact L.E. Bultman at Missouri Cities Water Co.. P.O. Bn< t077, St. Charles. MO 63301. or C. Percy at Larkin tv Assoc.. 9233 Ward Parkway. Suite 300. Kansas City. MO 64114.
AC pipe retains strength in corrosive water environment
An ongoing quality assurance program' shows nearly all asbestos-cement (AC) waterdistribution pipes still exceed structural requirements for new pipe even after many years' use.
Forty-five samples of AC pipe from geographically diverse areas and of varying ages were analyzed for loss of structural integrity and evidence of corrosive water attack. Emphasis was on older pipe installations conveying waters-that ranged from nonaggressive to highly aggressive (corrosive). More than 50 percent of the systems were 30 years old or older; several were 40 to 45 years old.
New AC pipe is subjected to physical inspection followed by strength and composition testing to control finished quality. Four tests are used; hydrostatic, flexure, crushing, and free lime. Detailed test procedures are set forth by two nationally recognized standards-setting organizations." All except the free-iime lest were used in this evaluation of the AC pipe field
samples. Field technicians obtained and verified the service history of
AC pipe samples provided by cooperating water utilities. Testing was carried out in a laboratory, for the most part on l2-in.-long samples. In addition, a depth-of-penetration anal
* rrjn mao
ysis was performed on a coupon from each sample. This was done by scraping away any soft material present on the inside surface of the pipe and then measuring the remaining wall thickness with a micrometer.
Overall, the data substantiate the ability of AC distribution pipe to convey moderately to highly aggressive water over a long period of time with little or no apparent loss of strength. The degree of corrosive attack is correlated with the aggressive index of the water. Even where corrosion was measured bydepth of penetration, structural integrity was maintained.
References
1. Hkrr, J.F.Trnnsite Pipe Field Study Program. ]nhns-ManvilleCorp. Res. & Dev. Ctr.. Rept. E 425-T-1424 (Aug. 22.1980).
2. AWWAC400-80, Asbestos-Cement DistributionPipe.4 in.Through 1G in., and AWWA C402-77, Asbestos-Cement Transmission Pipe. 18 in. Through 42 in. AWWA. Denver. Colo.
3. ASTM C296-78. Standard Specification for Asbestos-Cement Pressure Pipe; ASTM C500-79a. Standard Methods Tor Testing Asbpstos-Cenient Pipe; and ASTM CP88-79. Standard Specification for Asbestos-Cement Transmission Pipe. ASTM. Philadelphia. Pa.
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