| (vii) Gravity filters installed after January 1, 1996,
shall be equipped with air scour backwash or surface wash facilities.
(G) Each filter installed after October 1, 2000, shall
be equipped with facilities that allow the filter to be completely
drained without removing other filters from service.
(12) Pipe galleries shall provide ample working room,
good lighting, and good drainage provided by sloping floors, gutters,
and sumps. Adequate ventilation to prevent condensation and to provide
humidity control is also required.
(13) The identification of influent, effluent, waste
backwash, and chemical feed lines shall be accomplished by the use
of labels or various colors of paint. Where labels are used, they
shall be placed along the pipe at no greater than five-foot intervals.
Color coding must be by solid color or banding. If bands are used,
they shall be placed along the pipe at no greater than five-foot intervals.
(A) A plant that is built or repainted after October
1, 2000, must use the following color code. The color code to be used
in labeling pipes is as follows:
Attached Graphic
(B) A plant that was repainted before October 1, 2000,
may use an alternate color code. The alternate color code must provide
clear visual distinction between process streams.
(C) The system must maintain clear, current documentation
of its color code in a location easily accessed by all personnel.
(14) All surface water treatment plants shall provide
sampling taps for raw, settled, individual filter effluent, and clearwell
discharge. Additional sampling taps shall be provided as appropriate
to monitor specific treatment processes.
(15) An adequately equipped laboratory shall be available
locally so that daily microbiological and chemical tests can be conducted.
(A) For plants serving 25,000 persons or more, the
local laboratory used to conduct the required daily microbiological
analyses must be accredited by the executive director to conduct coliform
analyses.
(B) For plants serving populations of less than 25,000,
the facilities for making microbiological tests may be omitted if
the required microbiological samples can be submitted to a laboratory
accredited by the executive director on a timely basis.
(C) All surface water treatment plants shall be provided
with equipment for making at least the following determinations:
(i) pH;
(ii) temperature;
(iii) disinfectant residual;
(iv) alkalinity;
(v) turbidity;
(vi) jar tests for determining the optimum coagulant
dose; and
(vii) other tests deemed necessary to monitor specific
water quality problems or to evaluate specific water treatment processes.
(D) Each surface water treatment plant that uses chlorine
dioxide shall provide testing equipment for measuring chlorine dioxide
and chlorite levels.
(E) Each surface water treatment plant that uses sludge-blanket
clarifiers shall be equipped with facilities to monitor the depth
of the sludge blanket.
(F) Each surface water treatment plant that uses solids-recirculation
clarifiers shall be equipped with facilities to monitor the solids
concentration in the slurry.
(16) Each surface water treatment plant shall be provided
with a computer and software for recording performance data, maintaining
records, and submitting reports to the executive director. The executive
director may allow a water system to locate the computer at a site
other than the water treatment plant only if performance data can
be reliably transmitted to the remote location on a real-time basis,
the plant operator has access to the computer at all times, and performance
data is readily accessible to agency staff during routine and special
investigations.
(17) Reverse osmosis and nanofiltration membrane systems
not provided for microbiological quality control shall conform to
the requirements of subsection (b)(9) of this section.
(e) Disinfection.
(1) All water obtained from surface sources or groundwater
sources that are under the direct influence of surface water must
be disinfected in a manner consistent with the requirements of §290.110
of this title.
(2) All groundwater must be disinfected prior to distribution
and in a manner consistent with the requirements of §290.110
of this title. The point of application must be ahead of the water
storage tank(s) if storage is provided prior to distribution. Permission
to use alternate disinfectant application points must be obtained
in writing from the executive director.
(3) Disinfection equipment shall be selected and installed
so that continuous and effective disinfection can be secured under
all conditions.
(A) Disinfection equipment shall have a capacity at
least 50% greater than the highest expected dosage to be applied at
any time. It shall be capable of satisfactory operation under every
prevailing hydraulic condition.
(B) Automatic proportioning of the disinfectant dosage
to the flow rate of the water being treated shall be provided at plants
where the treatment rate varies automatically and at all plants where
the treatment rate varies more than 50% above or below the average
flow. Manual control shall be permissible only if an operator is always
on hand to make adjustments promptly.
(C) All disinfecting equipment in surface water treatment
plants shall include at least one functional standby unit of each
capacity for ensuring uninterrupted operation. Common standby units
are permissible but, generally, more than one standby unit must be
provided because of the differences in feed rates or the physical
state in which the disinfectants are being fed (solid, liquid, or
gas).
(D) Facilities shall be provided for determining the
amount of disinfectant used daily and the amount of disinfectant remaining
for use.
(E) When used, solutions of calcium hypochlorite shall
be prepared in a separate mixing tank and allowed to settle so that
only a clear supernatant liquid is transferred to the hypochlorinator
container.
(F) Provisions shall be made for both pretreatment
disinfection and post-disinfection in all surface water treatment
plants. Additional application points shall be installed if they are
required to adequately control the quality of the treated water.
(G) The use of disinfectants other than free chlorine
and chloramines will be considered on a case-by-case basis under the
exception guidelines of §290.39(l) of this title. If water containing
chloramines and water containing free chlorine are blended, then a
case-by-case review under §290.39(l) of this title will be required.
(4) Systems that use chlorine gas must ensure that
the risks associated with its use are limited as follows.
(A) When chlorine gas is used, a full-face self-contained
breathing apparatus or supplied air respirator that meets Occupational
Safety and Health Administration (OSHA) standards for construction
and operation, and a small bottle of fresh ammonia solution (or approved
equal) for testing for chlorine leakage shall be readily accessible
outside the chlorinator room and immediately available to the operator
in the event of an emergency.
(B) Housing for gas chlorination equipment and cylinders
of chlorine shall be in separate buildings or separate rooms with
impervious walls or partitions separating all mechanical and electrical
equipment from the chlorine facilities. Housing shall be located above
ground level as a measure of safety. Equipment and cylinders may be
installed on the outside of the buildings when protected from adverse
weather conditions and vandalism.
(C) Adequate ventilation, which includes both high
level and floor level screened vents, shall be provided for all enclosures
in which gas chlorine is being stored or fed. Enclosures containing
more than one operating 150-pound cylinder of chlorine shall also
provide forced air ventilation which includes: screened and louvered
floor level and high level vents; a fan which is located at and draws
air in through the top vent and discharges to the outside atmosphere
through the floor level vent; and a fan switch located outside the
enclosure. Alternately, systems may install negative pressure ventilation
as long as the facilities also have gas containment and treatment
as prescribed by the current International Fire Code (IFC).
(5) Hypochlorination solution containers and pumps
must be housed in a secure enclosure to protect them from adverse
weather conditions and vandalism. The solution container top must
be completely covered to prevent the entrance of dust, insects, and
other contaminants.
Cont'd... |
