Dissolving Tanks for Calcium Hypochlorite Feed System
April 18, 1912: Municipal Journalarticle. Water Purification at Trenton. By Howard C. Hottel. “As a result of investigations made by the New Jersey State Board of Health, the city of Trenton, on November 9, 1911, started to purify its drinking water supply, raw Delaware River water, by the use of calcium hypochlorite.
Previous analysis of the water had shown that there was more or less constant pollution, liable to increase under certain weather conditions, and at the time that the plant was ready to start operation there was a typhoid epidemic in progress at Trenton.
The chemical purchased when tested was found to have 35 per cent available chlorine and treatment was begun with a strength of about 0.4 to the million of available chlorine. This was found to be insufficient and on November 28 the dose was raised to 0.8 and has since then varied from 0.8 to 1.0 part per million, with a daily pumpage of about 20,000,000 gallons. In commercial terms this means that from 20 to 25 pounds of calcium hypochlorite are being added to every million gallons of water that is being pumped.
After the chemical had been increased the intestinal bacteria began to disappear, as shown by tests made by the State Board of Health. Inasmuch as the pipe area is rather large it took some time before the tap water gave negative tests for B. coli.
There has been considerable complaint from the taxpayers, who claim that the chemical gives a slight taste to the water. In fact, some would seem to prefer taking chances with typhoid rather than purification by treatment with calcium hypochlorite. The treatment, however, will probably continue until a permanent purification plant is established. Plans are already being drawn for the erection of a mechanical filtration plant, with the expectation of having the same completed within a year.
Shortly after the hypochlorite treatment was begun the typhoid dropped abruptly and a few statistics may prove interesting. During the month of November, 1911, there were 82 cases of typhoid reported, and during December 49. For the first three months of 1912 there has been a total of only 15 cases; in 1911 for the same three months there were 52; in 1910, 47.”
Reference: Hottel, Howard C. 1912. “Water Purification at Trenton.” Municipal Journalarticle. 32:16(April 18, 1912): 589.
Commentary: There were people in Trenton who opposed any move to treat the disease-laden water from the Delaware River. It is incomprehensible that they resisted all attempts. Below is an excerpt from my book The Chlorine Revolution: Water Disinfection and the Fight To Save Lives.
“Trenton, the capital of New Jersey, was home to about 97,000 citizens in 1911. The city’s water source was the Delaware River, which had been grossly contaminated with sewage for decades. Typhoid fever was ever-present in the city, and occasionally epidemics broke out, causing much higher death rates. The typhoid fever death rate during 1902–1911 ranged from 26.2 to 84.3 per 100,000 people, with an average of 49.7 per 100,000.
Despite the water supply’s wholesale killing of Trenton’s citizens, there was tremendous opposition to installing filtration or any other kind of effective treatment. Outstanding treatment experts such as Allen Hazen and George Warren Fuller prepared two separate designs for filtration plants, both of which languished without being implemented. Finally, the New Jersey Board of Health had had enough. In early 1910, the board issued a “compulsory order” for Trenton to treat its water supply and made the order effective shortly thereafter, on June 15. The Trenton Water Board began to install a chloride of lime feed system, but, incredibly, the local health board vetoed the plan. Wasting no time, the New Jersey Board of Health filed a lawsuit shortly after the June 15 deadline to compel the city to move forward with its plans.”
Solution Tanks for Calcium Hypochlorite Feed System