New Britain herald., 1924-09-04
CITY IN NEED OF
 NEW SEWAGE PLANT
(continued from First page)

Continued from First page) and adequate installation of same is the great problem ahead of the city. will give the rest of my time to e discussion of the work of the ex- perimental station. This station was located 'at the site of the New Britain sewage disposal plant. Continuous 24 hours sampling and operating began May 24, 1920. The station consisted of pumping plant. grit chamber, main weir box, activated sludge plant Imhoff sprinkling filter plant, Miles acid plant. screening plant. and an oper- ating building.
 ''The systems considered were the present process of large area filter beds for intermittent operation useA with or without preliminary screen. actiyated sludge process, Imhoff sprinkling filter process, Miles acid process.
 "The present system consists Of sewer beds built in 1904, 32 beds of one acre each, and one added later of five acres area. A small per cent of the area Is clay, the rest fl gravel and lpam. The beds are un- drained and when working properly the process k as follows:
 ''1'he sewage is run onto filter bed and then shut eff from that bed and run onto another. The watei passes through the bed to tn, drains. The bed Is allowed to dr! and the sun and air on the sur. face. and the air ell down through the Alter bed act on the sewage ant exidiZe it to a stable condition This bed again B flooded and the action repeated. About once as month the dry solids are taker from the surface and truoked tc the. dump.
 Factory Wastes Clog Filters.
 One of the great troubles ha, been due to factory wastes whicf have clogged the filters and under drains thus preventing the filter from drying. This prevents ail from passing down through the fil ters and oxidising this sewage.
 When the filters clog then tn, unfiltered sewage overnows into Will
 low Brook, and 50 into the Matta bessett river.
 Recently Dorr screen was in stalled through which the sewag, passes before going to the filter beds This Dorr screen takes out abou
 25 per cent of the suspended solids
 and thus greatly relieves the load O,
 the filters. The effluent from tn
 Dorr screen goes onto the beds an,
 is acted on by sun and air, as de
 scribed above. This arrangement o
 screen and filters has been operatini
 for some time and conditions ar
 somewhat better than before tn
 screen was added but they are yer
 far from satisfactory, and we ar
 faced with the immediate necessit
 of Installing an up-to-date efficien
 system for disposing of the sewage T "The results of the tests made a
 the experimental station are yer
 valuable in giving us information { make it possible to decide on tn
 proper plant to put in, and the sig this plant should be. There can b no excuse for further delay, and tn money must be appropriated.
 "As I said above, the three plar , studied were: Miles acid process, ac tivated sludge, 1mhoff sprinklin , filter. In the Miles acid process , sulphurous anhydride, s o 2. is ir : troduced into the sewage. The re , action that follows liberates fire j fatty acids, and also has germ,
 cidal effect on the bacteria. Tn sludge is dried and treated wit !, naphtha or a similar solvent, an the grease thus recovered is used fc soaps and greases.
 '"The experimental plant consist ed of a tank about it. in diamete I } and Il ft deep. The sewage wa r run in through four inch pipe, TUT 7 ming down about one foot below tt
 water level, then horizontal to tf
 center of the tank. and then dow to a point IS inches from the bo tom. The low end of the pipe ws expanded to bell shape.
 'The S O gas was introduce into the sewage from cylinder an the most satisfactory place to 1T troduce 1t was found to be in tn vertical pipe about three feet aboy the bell end. This process prove unsatisfactory and was dropped. "The two other processes, activat ed sludge and Imhoff sprinklfng fl ter, were tried and both proved sal isfactory. Both processes plan t make the sludge or residue stabl through oxidation and bacteriologi cal action. More or less of the solid become soluble by the process an are carried of in a clear and odor less effluent.
 "The activated sludge process use
 the Arobic bacteria, which require
 plenty of air for their life an
 growth. The 1mhoff sprinkling filte process uses a septic tank in whic