Dr Frank Seymour's report to the Local Government Board on the occurrence of lead poisoning in the Urban District of Guisborough, and its relation to the public water supply.

  • Seymour, Frank.
Date:
1913
Catalogue details

Licence: In copyright

Credit: Dr Frank Seymour's report to the Local Government Board on the occurrence of lead poisoning in the Urban District of Guisborough, and its relation to the public water supply. Source: Wellcome Collection.

    13/26 (page 11)
    by Dr. J. C. Thresh, showed no lead in solution, but the samples were reported to be “ capable of acting on lead to a sliglit extent.” Reporting’ on two samples taken from town mains on 28th December, 1911, Di\ Thresh said :—“ The waters contain an intinitcsimal and qiutc negligible quantity of lead, but both are capable of taking up a considerable quantity of that metal, fully ^ grain per gallon in 24 hours.” 3. A few cases of lead poisoning had occurred before 1912 which were referable to the water.* Definite complaints of the activity of the water in regard to lead were made to the Company in 1910. 4. The ability of the water to act on lead was recognised in con- nection with the issue of the Board of Trade Order of 1911, which contained a clause requiring treatment to prevent action on lead to be undertaken after January 1, 1914. ' Treatment of the water before 1912. According to the information supplied to me by the water com- pany, the sole method of treatment of the water up to 1904 was by means of sand filtration, adopted for the purpose of removing organic impurities, and without reference to the question of action on lead. About that time difficulty in obtaining suitable sand was experienced, and the filters gradually fell into disuse. Two mechanical filters were then supplied by the Candy Filter Com- pany, Limited. These filters, which were supplied for the same purpose as the sand filters, are situated close to the town, and filtration in them is carried out by means of polarite and sand. Their size is such that the total superficies of filtering surface is about 56^ square feet. Since the average daily consumption of water is 130,000 gallons, the water must pass through the filters at an average speed of about 3 inches per minute ; since the filters are 8 feet deep the water is only in contact with the filtering material for 32 minutes. In practice the water will sometimes pass through the filters much more rapidly, the demand being greater at certain times of the day than at others. The filters are washed periodically twice a week. In order to do this the filter which is undergoing washing is necessarily thrown out of action, while a considerable proportion of the water passing through the second filter is employed to produce a back flow in the first, so that for filtering purposes about half the capacity of a single filter is all that is available at such times. The result of this is either that water drawn off immediately after the filters have been washed has been “ rushed ” through the filters, or that the distributing mains get partially emptied, and when refilled, any incrustation or deposit in the pipes is disturbed, rendering the water turbid.t Treatment in 1912 and mb&eijuently, Two samples taken from town mains on 22 January, 1912, were found by Dr. Thresh to contain no lead in solution, but one of them was capable of dissolving about *07 grains of lead per gallon. See p. 2. t This was pointed out l)y the Candy Filter Company in 1910. An eifort has been made to counteract this tendency by washing the filters at a time when little water is likely to be drawn off in the town.