Document aJ98e03Qw5XD5MyE3opZRpLjb

Effluent Treatment GRP Fabrications Our Ref: BDR/DLC 29 May 1985 Air Products Limited Hersham Place Molsley Road Hersham WALTON ON THAMES Tel 0274-729361 C T' I Telex 517153 Dear Sirs RE: LEGIONAIRES DISEASE We enclose for your information a note we have prepared on the very topical subject of Legionaires Disease. , The object of the note is to allay some of the concerns which recent uninformed publicity may have produced and to indicate the necessary treatment which can effectively eliminate the problem. If you require any further help please do not hesitate to contact us. Yours faithfully Davenport Engineering Co Ltd B D Ripley Marketing Manager Encs O.ivonnc.t t Mi- me C*-. < j.rnit* *d H.itri:? St r s:r-.id. W.\5t Yorkshire. RD1 5jD. AP00036676 Effluent Treatment GRP Fabrications Our Ref: BDR/DLC 29 May 1985 Air Products Limited Hersham Place Molsley Road Hersham WALTON ON THAMES Tei 0274-729361 Telex 517153 C T' I *1MEM1BER-: Cc >"i"Q InMItutP MEMBER Fflf*Cion of Civil EngmotriAf Coniiociot Dear Sirs RE: LEGIONAIRES DISEASE We enclose for your information a note we have prepared on the very topical subject of Legionaires Disease. The object of the note is to allay some of the concerns which recent uninformed publicity may have produced and to Indicate the necessary treatment which can effectively eliminate the problem. If you require any further help please do not hesitate to contact us. Yours faithfully Davenport Engineering Co Ltd B D Ripley Marketing Manager Encs D.rvonpf.ji C mitcci Hai ns Sir* :.n!Vjii. Yorkshire. RDl 5JI). AP00036677 LEGIONAIRES DISEASE - THE CAUSE AMD PREVENTION OF LEGIONELLA PNEUMOPHILA IN WATER COOLING TOWERS Legi.oaai.res disease is caused by the bacterial cell Legionella Pneumophila. It was first identified in 1977 as a result of research into the cause of the mysterious deaths of several ex legionaires following the Philadelphia convention in 1976. A few cells of the bacteria were isolated in samples taken following the convention and were named after the convention outbreak. Subsequently, many other members of the Legionella genus have been identified aa possible causes of the infection. Although relatively new in name, Legionaires disease will over the years have been responsible for the outbreak of many epedemics throughout the world. Symptoms of the disease manifest themselves within 2 to 10 days of exposure and include headache, high temperatures, muscle aches, coughing, vomiting and diarrhoea. In a natural environment Legionella has been identified around the world in the muds found in rivers and lakes with the highest infestations being where soil and water contact each other. The risk of infection from natural sources in the UK is insignificant due to the very low concentrations and the adverse temperature and other conditions for the proliferation of the bacteria. The favourable environment for the growth of the bacteria found in certain man made water systems, such as cooling towers, humidifiers, hot and cold water pLped vicar systems and shower heads can allow the development of high concentrations of bacteria, vhich greatly increase the risk of infection. Growth of Legionella is favoured in neutral pH conditions and where temperatures are in the region of 20 Deg C to 70 Deg C, with temperatures in the mid range being most favourable, at lower temperatures the bacteria can exist in a dormant state in deposits of silt and other debris. ALso essential for growth is a source of nutrients which include nitrogen, iron and the amino acid cysteine. In addition the evaporation of water vapour, vhich occurs in cooling towers causes the concentration of dissolved solids and biological organisms in the circulating water to be increased from 2 to 10 times that in the make-up water supplied to the cooling tower. Airborne spread of the bacteria through the inhalation of water dropLets arising from the carry over from cooling towers and the spray from showers is s frequent cause of infection. ------- f AP00036678 ... .2 Tests for the presence of the organism in the circulating water of cooling towers, in which the water quality is adequately controlled and treated have invariably proved negative. It is, however, occasionally Identified vhere Che water quality is inadequately managed. Although cooling water systems have previously been wrongly blamed as a major source of the infection, it has been confirmed that contaminated cooling water has been associated with outbreaks of the disease . Good maintenance of the cooling water system ensures that conditions in the circulating water are not conducive to the growth of the organism* Scale and corrosion cause the build up of deposits within heat exchangers, pipework, the cooling tower and its sump. These deposits provide a sheltered environment for the development of high concentrations of the organism. Dosing the waters with appropriate scale or corrosion inhibitors is essential. In addition its effect is to increase process efficiency and to decrease maintenance costs. Organic materials can enter the cooling water through process contamination, contaminated make-up water derived from rivers etc or be carried into the cooling tower with the air. These organic materials provide a food source for the growth of micro organisms such as Legionella pneumophila as well as the more usual bioLogical slimes, algae and fungi found in cooling towers. Chlorine and organic based biocides are added to the circulating water in slug doses to oxidise the organic matter and to sterilise Living organisms. Chlorine based biocides such as gaseous chlorine, sodium hypochlorite end chlorine dioxide are very effective, but have short system lives as the residual chlorine is stripped from the water as it passes through the cooling cover. It is usually added at a race of 1 to 5 ppm over a 30 minute period on a daily basis. Organic biocides are available from water treatment chemical suppLiars containing blends of active compounds and dispersants, being non volatile, extended contact periods are possible so exercising control in stagnant areaa vhere chlorine would not have the opportunity to penetrate. Organic biocides are usually added in slug doses on a weekly basis often in association with daiLy chlorination. The dispersants present in the solutions help detach dead cellular material from the heat transfer surfaces and keep them in suspension for discharge from Che system in the blow down. ----- / AP00036679 The effecCiveaess of the biological control programme can be established through regular counts of micro biological population within the system with biocide dosage the rates being adjusted to maintain acceptable counts. These can be backed up by annual selective counts for Legionella pneumophila, the absence of the bacteria is not necessarily confirmed by a lov count of the total population. Silt deposits can build up very rapidly in water cooling systems where untreated river vater is used as the make-up source or where there is a dusty environment. The basin of the cooling tower, distribution troughs and stagnant areas in process plants allow suspended solids to settle, so creating a suitable breeding environment for Legionella pneumophila. To minimise the-effects of silt deposits dispersants can be added to the water to keep them in suapensionor side stream filtration facilities can be provided to remove solids from the circulating water. The level of silt deposits in the cooling tower basin and cooling tower internals should be checked at least on an annual baaia and arrangements made for cleaning. The process line diagram shows a typical cooling water treatment system, which would effectively control the use of water and treatment chemicals associated with a medium to large scale cooling tower in a hard vater area. When operated in a competent manner the system would ensure that all reasonable steps had been taken to prevent the ) development of Legionella pnuemophila and the spread of Leglonaire* disease. TYPICAL ARRANGEMENT OF DAVENPORT SCHEME AP00036680 PETROLEUM COKE DUST AP00036681 .V^emcrEntum ) C <Z PRODUCTS " To: From: Date: Subject: D. S. Zuck __ Dept.: E. C. Grassland 9 July 1985 Dept./Ext.: Long Beach Industrial Hygiene Survey IGD Specialty Gas - Long Beach IGD Technical Affairs/5589 cc: E. H. Alkire (without attachment) J. A. DeSanto K. A. Eaton N. R. John R. J. Lomicky R. 0. Wood (without attachment) In response to the safety review conducted by R. Flaska on 5 March 1985, which noted potential worker exposures to emissions from neighboring plants, an industrial hygiene survey has been requested by IGD Techni- V cal Affairs. The results of this survey conducted by the Corporate /\ Medical Department are attached. There'were no exposure levels found above any regulated occupational exposure standards. However, Corporate Medical's report makes several suggestions which would reduce the poten tial for health impact from these releases. Below is a summary of the suggestions which can and should be imple mented by you immediately on a local level. It is my understanding based on our recent conversation that most of these Items have already been initiated. The suggestions include: Providing self-contained breathing apparatus (2 units) along the north fenceline for use as necessary, Supplementing the site's emergency procedures to Include responses to HS releases. Providing dust masks (3M-8710 or equivalent) to employees working outdoors for extended periods of time or during excessively dusty periods. Discontinue sweeping of coke dust-contaminated areas and replace with wet or dry vacuuming procedures. J. A. DeSanto will develop cost estimates for the recommendations re quiring capital improvements. These are the installation of a multi.ple point H$ monitor/alarm and the enclosure of the specialty gas building. c The periodic employee physical examinations and followup air monitoring also suggested In Corporate Medical's report will be initiated by Corporate Medical and Technical Affairs. If you should have any ques tions or are in need of any assistance in this matter, please do not hesitate to contact me at Extension 5589. ECC/cn Attachment AP00036682 Memorandum To: From: E. H. Alkire R. d. \ s-/ Deal , Technical Affairs Deot. s.xt.. Corporate Medical Date. 26 June 1985 Subject; Industrial Hygiene Survey Long Beach, Specialty Gas MR J* PRODUCTS SZ cc: E. C. Crossland Attached are the results of the industrial hygiene survey conducted April 15-17, 1S85 at the Long Beach, California, Specialty Gas facility. The following comments are based on observations and measurements made during the survey. If you have any questions, please feel free to call. Summary 1. Hydrogen Sulfide (H2SI A potential H2S hazard exists for all Long Beach site personnel. The primary source of H2S emissions is the sulfur extraction plant on the north side of the APCI site. A multiple-point continuous H^S monitor and alarm system should be installed. Employees working near the north fence line should have access to SCBA escape packs and site emergency procedures should be written. 2. Petroleum Coke Dust s-- Air monitoring was conducted both Inside and outside the Spec Gas building. Analysis of the samples indicated elevated total particulate concentrations and the presence of polynuclear aromatics (PNA's). The Spec Gas building should be enclosed to the greatest extent feasible. A ventilation system having proper filtration capabilities should be installed In the building. Employees working outside the building for extended periods of time should wear respirators. Work areas should be vacuumed to minimize airborne dust generation caused by housekeeping activities. AP00036683 Page Two Periodic physical examinations should be offered to site personnel and periodic exposure monitoring should be conducted. 3. Arsine Arsine exposure monitoring was conducted during the disposal of arsine through the dopant scrubber. Both personal and area arsine concentrations were well within acceptable limits. Provisions should be made for securing dopant cylinders to the rack during the unloading procedure. RDW:bmw Att. AP00036684