| (G) a copy of all data relied upon for making the proposed
determination.
(2) Alternative capacity requirements for existing
public water systems must be based upon the maximum daily demand for
the system, unless the request is submitted by a licensed professional
engineer in accordance with the requirements of paragraph (3) of this
subsection. The maximum daily demand must be determined based upon
the daily usage data contained in monthly operating reports for the
system during a 36 consecutive month period. The 36 consecutive month
period must end within 90 days of the date of submission to ensure
the data is as current as possible.
(A) Maximum daily demand is the greatest number of
gallons, including groundwater, surface water, and purchased water
delivered by the system during any single day during the review period.
Maximum daily demand excludes unusual demands on the system such as
fire flows or major main breaks.
(B) For the purpose of calculating alternative capacity
requirements, an equivalency ratio must be established. This equivalency
ratio must be calculated by multiplying the maximum daily demand,
expressed in gpm per connection, by a fixed safety factor and dividing
the result by 0.6 gpm per connection. The safety factor shall be 1.15
unless it is documented that the existing system capacity is adequate
for the next five years. In this case, the safety factor may be reduced
to 1.05. The conditions in §291.93(3) of this title (relating
to Adequacy of Water Utility Service) concerning the 85% rule shall
continue to apply to public water systems that are also retail public
utilities.
(C) To calculate the alternative capacity requirements,
the equivalency ratio must be multiplied by the appropriate minimum
capacity requirements specified in subsection (b) of this section.
Standard rounding methods are used to round calculated alternative
production capacity requirement values to the nearest one-hundredth.
(3) Alternative capacity requirements which are proposed
and submitted by licensed professional engineers for review are subject
to the following additional requirements.
(A) A signed and sealed statement by the licensed professional
engineer must be provided which certifies that the proposed alternative
capacity requirements have been determined in accordance with the
requirements of this subsection.
(B) If the system is new or at least 36 consecutive
months of data is not available, maximum daily demand may be based
upon at least 36 consecutive months of data from a comparable public
water system. A licensed professional engineer must certify that the
data from another public water system is comparable based on consideration
of the following factors: prevailing land use patterns (rural versus
urban); number of connections; density of service populations; fire
flow obligations; and socio-economic, climatic, geographic, and topographic
considerations as well as other factors as may be relevant. The comparable
public water system shall not exhibit any of the conditions listed
in paragraph (6)(A) of this subsection.
(4) The executive director shall consider requests
for alternative capacity requirements in accordance with the following
requirements.
(A) For those requests submitted under the seal of
a licensed professional engineer, the executive director must mail
written acceptance or denial of the proposed alternative capacity
requirements to the public water system within 90 days from the date
of submission. If the executive director fails to mail written notification
within 90 days, the alternative capacity requirements submitted by
a licensed professional engineer automatically become the alternative
capacity requirements for the public water system.
(B) If the executive director denies the request:
(i) the executive director shall mail written notice
to the public water system identifying the specific reason or reasons
for denial and allow 45 days for the public water system to respond
to the reason(s) for denial;
(ii) the denial is final if no response from the public
water system is received within 45 days of the written notice being
mailed; and
(iii) the executive director must mail a final written
approval or denial within 60 days from the receipt of any response
timely submitted by the public water system.
(5) Although elevated storage is the preferred method
of pressure maintenance for systems of over 2,500 connections, it
is recognized that local conditions may dictate the use of alternate
methods utilizing hydropneumatic tanks and on-site emergency power
equipment. Alternative capacity requirements to the elevated storage
requirements may be obtained based on request to and approval by the
executive director. Special conditions apply to systems qualifying
for an elevated storage alternative capacity requirement.
(A) The system must submit documentation sufficient
to assure that the alternate method of pressure maintenance is capable
of providing a safe and uninterrupted supply of water under pressure
to the distribution system during all demand conditions.
(i) A signed and sealed statement by a licensed professional
engineer must be provided which certifies that the pressure maintenance
facilities are sized, designed, and capable of providing a minimum
pressure of at least 35 psi at all points within the distribution
network at flow rates of 1.5 gpm per connection or greater. In addition,
the engineer must certify that the emergency power facilities are
capable of providing the greater of the average daily demand or 0.35
gpm per connection while maintaining distribution pressures of at
least 35 psi, and that emergency power facilities powering production
and treatment facilities are capable of supplying at least 0.35 gpm
per connection to storage.
(ii) The system's licensed professional engineer must
conduct a hydraulic analysis of the system under peak conditions.
This must include an analysis of the time lag between the loss of
the normal power supply and the commencement of emergency power as
well as the minimum pressure that will be maintained within the distribution
system during this time lag. In no case shall this minimum pressure
within the distribution system be less than 20 psi. The results of
this analysis must be submitted to the executive director for review.
(iii) For existing systems, the system's licensed professional
engineer must provide continuous pressure chart recordings of distribution
pressures maintained during past power failures, if available. The
period reviewed shall not be less than three years.
(iv) A public water system that is an affected utility
must conduct the modeling requirements contained in clauses (i) -
(iii) of this subparagraph using the requirements specified in subsection
(h) of this section.
(B) Emergency power facilities must be maintained and
provided with necessary appurtenances to assure immediate and dependable
operation in case of normal power interruption. A public water system
that is an affected utility must meet the requirements specified in
subsection (h) of this section.
(i) The facilities must be serviced and maintained
in accordance with level 2 maintenance requirements contained in the
current NFPA 110 Standard and the manufacturers' recommendations.
(ii) The switching gear must be capable of bringing
the emergency power generating equipment on-line during a power interruption
such that the pressure in the distribution network does not fall below
20 psi at any time.
(iii) The minimum on-site fuel storage capacity shall
be determined by the fuel demand of the emergency power facilities
and the frequency of fuel delivery. An amount of fuel equal to that
required to operate the facilities under-load for a period of at least
eight hours must always be maintained on site.
(iv) Residential rated mufflers or other means of effective
noise suppression must be provided on each emergency power motor.
(C) Battery-powered or uninterrupted power supply pressure
monitors and chart recorders which are configured to activate immediately
upon loss of normal power must be provided for pressure maintenance
facilities. These records must be kept for a minimum of three years
and made available for review by the executive director. Records must
include chart recordings of all power interruptions including interruptions
due to periodic emergency power under-load testing and maintenance.
(D) An emergency response plan must be submitted detailing
procedures to be followed and individuals to be contacted in the event
of loss of normal power supply.
(6) Any alternative capacity requirement granted under
this subsection is subject to review and revocation or revision by
the executive director. If permission to use an alternative capacity
requirement is revoked, the public water system must meet the applicable
minimum capacity requirements of this section.
Cont'd... |
