| (G) Coagulant feed systems shall be designed so that
coagulants are applied to the water prior to or within the mixing
basins or chambers so as to permit their complete mixing with the
(i) Coagulant feed points shall be located downstream
of the raw water sampling tap.
(ii) Coagulants shall be applied continuously during
treatment plant operation.
(H) Chlorine feed units, ammonia feed units, and storage
facilities shall be separated by solid, sealed walls.
(I) Chemical application points shall be provided to
achieve acceptable finished water quality, adequate taste and odor
control, corrosion control, and disinfection
(g) Other treatment processes. Innovative/alternate
treatment processes will be considered on an individual basis, in
accordance with §290.39(l) of this title. Where innovative/alternate
treatment systems are proposed, the licensed professional engineer
must provide pilot test data or data collected at similar full-scale
operations demonstrating that the system will produce water that meets
the requirements of Subchapter F of this chapter (relating to Drinking
Water Standards Governing Drinking Water Quality and Reporting Requirements
for Public Water Systems). Pilot test data must be representative
of the actual operating conditions which can be expected over the
course of the year. The executive director may require a pilot study
protocol to be submitted for review and approval prior to conducting
a pilot study to verify compliance with the requirements of §290.39(l)
of this title and Subchapter F of this chapter. The executive director
may require proof of a one-year manufacturer's performance warrantee
or guarantee assuring that the plant will produce treated water which
meets minimum state and federal standards for drinking water quality.
(1) Package-type treatment systems and their components
shall be subject to all applicable design criteria in this section.
(2) Bag and cartridge filtration systems or modules
installed or replaced after April 1, 2012, and used for microbiological
treatment, can receive up to 3.0-log Giardia removal
credit, up to 2.0-log Cryptosporidium removal
credit for individual bag or cartridge filters, and up to 2.5-log Cryptosporidium removal credit for bag or
cartridge filters operated in series only if the cartridges or bags
meet the criteria in subparagraphs (A) - (C) of this paragraph.
(A) The filter system must treat the entire plant flow.
(B) To be eligible for this credit, systems must receive
approval from the executive director based on the results of challenge
testing that is conducted according to the criteria established by
40 Code of Federal Regulations (CFR) §141.719 (a) and the executive
(i) A factor of safety equal to 1.0-log for individual
bag or cartridge filters and 0.5-log for bag or cartridge filters
in series must be applied to challenge testing results to determine
(ii) Challenge testing must be performed on full-scale
bag or cartridge filters, and the associated filter housing or pressure
vessel, that are identical in material and construction to the filters
and housings the system will use for removal of
Cryptosporidium and Giardia.
(iii) Bag or cartridge filters must be challenge tested
in the same configuration that the system will use, either as individual
filters or as a series configuration of filters.
(iv) Systems may use results from challenge testing
conducted prior to January 5, 2006, if prior testing was consistent
with 40 CFR §141.719, submitted by the system's licensed professional
engineer, and approved by the executive director.
(v) If a previously tested filter is modified in a
manner that could change the removal efficiency of the filter product
line, additional challenge testing to demonstrate the removal efficiency
of the modified filter must be conducted and results submitted to
the executive director for approval.
(C) Pilot studies must be conducted using filters that
will meet the requirements of this section.
(3) Membrane filtration systems or modules installed
or replaced after April 1, 2012, and used for microbiological treatment,
can receive Cryptosporidium and Giardia removal credit for membrane filtration
only if the systems or modules meet the criteria in subparagraphs
(A) - (F) of this paragraph.
(A) The membrane module used by the system must undergo
challenge testing to evaluate removal efficiency. Challenge testing
must be conducted according to the criteria established by 40 CFR §141.719(b)(2)
and the executive director.
(i) All membrane module challenge test protocols and
results, the protocol for calculating the representative Log Removal
Value (LRV) for each membrane module, the removal efficiency, calculated
results of LRVC-Test, and the non-destructive performance test with
its Quality Control Release Value (QCRV) must be submitted to the
executive director for review and approval prior to beginning a membrane
filtration pilot study at a public water system.
(ii) Challenge testing must be conducted on either
a full-scale membrane module identical in material and construction
to the membrane modules to be used in the system's treatment facility,
or a smaller-scale membrane module identical in material and similar
in construction to the full-scale module if approved by the executive
(iii) Systems may use data from challenge testing conducted
prior to January 5, 2006, if prior testing was consistent with 40
CFR §141.719, submitted by the system's licensed professional
engineer, and approved by the executive director.
(iv) If a previously tested membrane is modified in
a manner that could change the removal efficiency of the membrane
product line or the applicability of the non-destructive performance
test and associated QCRV, additional challenge testing to demonstrate
the removal efficiency of the modified membrane and determine a new
QCRV for the modified membrane must be conducted and results submitted
to the executive director for approval.
(B) The membrane system must be designed to conduct
and record the results of direct integrity testing in a manner that
demonstrates a removal efficiency equal to or greater than the removal
credit awarded to the membrane filtration system approved by the executive
director and meets the requirements in clauses (i) - (ii) of this
(i) The design must provide for direct integrity testing
of each membrane unit.
(ii) The design must provide direct integrity testing
that has a resolution of 3 micrometers or less.
(iii) The design must provide direct integrity testing
with sensitivity sufficient to verify the log removal credit approved
by the executive director. Sensitivity is determined by the criteria
in 40 CFR §141.719(b)(3)(iii).
(iv) The executive director may reduce the direct integrity
testing requirements for membrane units.
(C) The membrane system must be designed to conduct
and record continuous indirect integrity monitoring on each membrane
unit. The turbidity of the water produced by each membrane unit must
be measured using the Hach FilterTrak Method 10133. The executive
director may approve the use of alternative technology to monitor
the quality of the water produced by each membrane unit.
(D) The level of removal credit approved by the executive
director shall not exceed the lower of:
(i) the removal efficiency demonstrated during challenge
testing conducted under the conditions in subparagraph (A) of this
(ii) the maximum removal efficiency that can be verified
through direct integrity testing used with the membrane filtration
process under the conditions in subparagraph (B) of this paragraph.
(E) Pilot studies must be conducted using membrane
modules that will meet the requirements of this section.
(F) Membrane systems must be designed so that membrane
units' feed water, filtrate, backwash supply, waste and chemical cleaning
piping shall have cross-connection protection to prevent chemicals
from all chemical cleaning processes from contaminating other membrane
units in other modes of operation. This may be accomplished by the
installation of a double block and bleed valving arrangement, a removable
spool system or other alternative methods approved by the executive
(4) Bag, cartridge or membrane filtration systems or
modules installed or replaced before April 1, 2012, and used for microbiological
treatment, can receive up to a 2.0-log removal credit for Cryptosporidium and up to a 3.0-log removal
credit for Giardia based on site specific
pilot study results, design, operation, and reporting requirements.
(5) Ultraviolet (UV) light reactors used for microbiological
inactivation can receive Cryptosporidium,
Giardia and virus inactivation credit if the reactors meet
the criteria in subparagraphs (A) - (C) of this paragraph.
(A) UV light reactors can receive inactivation credit
only if they are located after filtration.
(B) In lieu of a pilot study, the UV light reactors
must undergo validation testing to determine the operating conditions
under which a UV reactor delivers the required UV dose. Validation
testing must be conducted according to the criteria established by
40 CFR §141.720(d)(2) and the executive director.
(i) The validation study must include the following
factors: UV absorbance of the water; lamp fouling and aging; measurement
uncertainty of on-line sensors; UV dose distributions arising from
the velocity profiles through the reactor; failure of UV lamps and
other critical system components; inlet and outlet piping or channel
configuration of the UV reactor; lamp and sensor locations; and other
parameters determined by the executive director.
(ii) Validation testing must be conducted on a full-scale
reactor that is essentially identical to the UV reactor(s) to be used
by the system and using waters that are essentially identical in quality
to the water to be treated by the UV reactor.
(C) The UV light reactor systems must be designed to
monitor and record parameters to verify the UV reactors operation
within the validated conditions approved by the executive director.
The UV light reactor must be equipped with facilities to monitor and
record UV intensity as measured by a UV sensor, flow rate, lamp status,
and other parameters designated by the executive director.
(h) Sanitary facilities for water works installations.
Toilet and hand washing facilities provided in accordance with established
standards of good public health engineering practices shall be available
at all installations requiring frequent visits by operating personnel.
(i) Permits for waste discharges. Any discharge of
wastewater and other plant wastes shall be in accordance with all
applicable state and federal statutes and regulations. Permits for
discharging wastes from water treatment processes shall be obtained
from the commission, if necessary.
(j) Treatment chemicals and media. All chemicals and
any additional or replacement process media used in treatment of water
supplied by public water systems must conform to American National
Standards Institute/National Sanitation Foundation (ANSI/NSF) Standard
60 for direct additives and ANSI/NSF Standard 61 for indirect additives.
Conformance with these standards must be obtained by certification
of the product by an organization accredited by ANSI.
(1) Safety equipment for all chemicals used in water
treatment shall meet applicable standards established by the OSHA
or Texas Hazard Communication Act, Texas Health and Safety Code, Title
6, Chapter 502.
(2) Systems must comply with United States Environmental
Protection Agency (EPA) requirements for Risk Management Plans.
(l) Plant operations manual. A thorough plant operations
manual must be compiled and kept up-to-date for operator review and
reference. This manual should be of sufficient detail to provide the
operator with routine maintenance and repair procedures, with protocols
to be utilized in the event of a natural or man-made catastrophe,
as well as provide telephone numbers of water system personnel, system
officials, and local/state/federal agencies to be contacted in the
event of an emergency.
(m) Security. Each water treatment plant and all appurtenances
thereof shall be enclosed by an intruder-resistant fence. The gates
shall be locked during periods of darkness and when the plant is unattended.
A locked building in the fence line may satisfy this requirement or
serve as a gate.
(n) Corrosion control treatment. Systems must install
any corrosion control or source water treatment required by §290.117(f)
and (g) of this title (relating to Regulation of Lead and Copper),
respectively. Such treatment must be designed and installed consistent
with the requirements of this subchapter. The requirements of 40 CFR §141.82(i)
and §141.83(b)(7) relating to EPA involvement in treatment determination
are adopted by reference.
|Source Note: The provisions of this §290.42 adopted to be effective September 13, 2000, 25 TexReg 8880; amended to be effective May 16, 2002, 27 TexReg 4127; amended to be effective February 19, 2004, 29 TexReg 1373; amended to be effective January 9, 2008, 33 TexReg 198; amended to be effective May 15, 2011, 36 TexReg 2860; amended to be effective September 12, 2013, 38 TexReg 5880