Transactions of the American Society of Civil Engineers, vol. LXXII, June, 1911 Water Purification Plant, Washington, D. C. Results of Operation.

=======+===========+===========+=================+==================== |Preliminary| Final | Turbidity. | Bacteria. | Filter. | Filter. | | Date. |-----+-----+-----+-----+-----+...

~Table 19--Record of Experimental Filter Plant. No. 3.~ ========+===============+============================ | ~Sand Filter.~| ~Turbidity.~ +---------------+-------+----------+...

In late years, however, there has been a tendency to depart from this fundamental doctrine of slow sand filtration. Various new processes for cleaning the sand surface have been...

~Table 18--Record of Experimental Filter Plant No. 2.~ ========+=====================+===================== |~Preliminary Filter.~| ~Final Filter.~ +-----------+---------+------...

A clearer conception of the capacities of the filters under these different conditions may be obtained from the four diagrams, Figure 12, showing, for the four different groups,...

~Table 4--Bacteria.~ Averages by Months. =============+======================================================= | ~Reservoirs:~ +----------+----------+----------+-------------+--...

~Table 23--Relative Cost of Filtering at Different Rates.~ ======================+=================================================== |Nominal rate, in millions of gallons per a...

Another topic in Mr. Hardy's paper which has interested the writer is that of preliminary filters. The experiments described at length indicate clearly that such devices would p...

The Washington filtration plant has already been fully described.[2] At the time that paper was written (November, 1906), the filtration plant had been in operation for only abo...

~Table 20--Summary of Results of Experimental Filters.~ ==================+========+========+========+=========+=========+======== Filter number.....| 1 | 2 | 3 | 4 | 5 | 6 | |...

~Table 19~--(_Continued._) ========+==============================+============ | ~Bacteria.~ |~Coagulant.~ +---------+----------+---------+------------ Date. | Applied | Efflue...

~Table 18~--(_Continued._) ========+===========================+=========================== | ~Turbidity.~ | ~Bacteria.~ +-------+---------+---------+-------+---------+---------...

~Table 8--Average Consumption of Water for Twenty-four Hours, Per Million Gallons.~ ==========+================================================ | ~Fiscal years.~ Month. +-----+-...

In order that the data may be in sufficient detail to permit it to be rearranged to compare with other plants, a list of employees and charges for supplies is given in Table 13....

Columns: A - Rates, millions of gallons per acre daily. B - Rate, millions of gallons per acre daily. C - Loss of head. D - Applied water. E - Effluent, preliminary filter. F -...

_Hydraulic Replacing of Filter Sand._--The author has adopted a method of replacing clean sand in the filters which will commend itself to engineers as containing possibilities...

When the water was comparatively clear, either one of the three systems, or slow sand filtration alone, was entirely satisfactory. At times of high turbidity, however, Filter Pl...