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TITLE 30ENVIRONMENTAL QUALITY
PART 1TEXAS COMMISSION ON ENVIRONMENTAL QUALITY
CHAPTER 290PUBLIC DRINKING WATER
SUBCHAPTER DRULES AND REGULATIONS FOR PUBLIC WATER SYSTEMS
RULE §290.45Minimum Water System Capacity Requirements

(a) General provisions.

  (1) The requirements contained in this section are to be used in evaluating both the total capacities for public water systems and the capacities at individual pump stations and pressure planes which serve portions of the system that are hydraulically separated from, or incapable of being served by, other pump stations or pressure planes. The capacities specified in this section are minimum requirements only and do not include emergency fire flow capacities for systems required to meet requirements contained in §290.46(x) and (y) of this title (relating to Minimum Acceptable Operating Practices for Public Drinking Water Systems).

  (2) The executive director will require additional supply, storage, service pumping, and pressure maintenance facilities if a normal operating pressure of 35 pounds per square inch (psi) cannot be maintained throughout the system, or if the system's maximum daily demand exceeds its total production and treatment capacity. The executive director will also require additional capacities for a system that is unable to maintain a minimum pressure of 20 psi during fire fighting, line flushing, other unusual conditions, and systems that are required to provide fire flow as specified in §290.46(x) and (y) of this title.

  (3) The executive director may establish additional capacity requirements for a public water system using the method of calculation described in subsection (g)(2) of this section if there are repeated customer complaints regarding inadequate pressure or if the executive director receives a request for a capacity evaluation from customers of the system.

  (4) Throughout this section, total storage capacity does not include pressure tank capacity.

  (5) The executive director may exclude the capacity of facilities that have been inoperative for the past 120 days and will not be returned to an operative condition within the next 30 days when determining compliance with the requirements of this section.

  (6) The capacity of the treatment facilities shall not be less than the required raw water or groundwater production rate or the anticipated maximum daily demand of the system.

  (7) If a public water system that is an affected utility fails to provide a minimum of 35 psi throughout the distribution system during emergency operations as soon as it is safe and practicable following the occurrence of a natural disaster, a revised emergency preparedness plan or justification regarding pressure drop shall be submitted for review and approval within 180 days of the date normal power is restored. Based on the review of the revised emergency preparedness plan, the executive director may require additional or alternative auxiliary emergency facilities.

(b) Community water systems.

  (1) Groundwater supplies must meet the following requirements.

    (A) If fewer than 50 connections without ground storage, the system must meet the following requirements:

      (i) a well capacity of 1.5 gallons per minute (gpm) per connection; and

      (ii) a pressure tank capacity of 50 gallons per connection.

    (B) If fewer than 50 connections with ground storage, the system must meet the following requirements:

      (i) a well capacity of 0.6 gpm per connection;

      (ii) a total storage capacity of 200 gallons per connection;

      (iii) two or more service pumps having a total capacity of 2.0 gpm per connection; and

      (iv) a pressure tank capacity of 20 gallons per connection.

    (C) For 50 to 250 connections, the system must meet the following requirements:

      (i) a well capacity of 0.6 gpm per connection;

      (ii) a total storage capacity of 200 gallons per connection;

      (iii) two or more pumps having a total capacity of 2.0 gpm per connection at each pump station or pressure plane. For systems which provide an elevated storage capacity of 200 gallons per connection, two service pumps with a minimum combined capacity of 0.6 gpm per connection are required at each pump station or pressure plane. If only wells and elevated storage are provided, service pumps are not required; and

      (iv) an elevated storage capacity of 100 gallons per connection or a pressure tank capacity of 20 gallons per connection.

    (D) For more than 250 connections, the system must meet the following requirements:

      (i) two or more wells having a total capacity of 0.6 gpm per connection. Where an interconnection is provided with another acceptable water system capable of supplying at least 0.35 gpm for each connection in the combined system under emergency conditions, an additional well will not be required as long as the 0.6 gpm per connection requirement is met for each system on an individual basis. Each water system must still meet the storage and pressure maintenance requirements on an individual basis unless the interconnection is permanently open. In this case, the systems' capacities will be rated as though a single system existed;

      (ii) a total storage capacity of 200 gallons per connection;

      (iii) two or more pumps that have a total capacity of 2.0 gpm per connection or that have a total capacity of at least 1,000 gpm and the ability to meet peak hourly demands with the largest pump out of service, whichever is less, at each pump station or pressure plane. For systems which provide an elevated storage capacity of 200 gallons per connection, two service pumps with a minimum combined capacity of 0.6 gpm per connection are required at each pump station or pressure plane. If only wells and elevated storage are provided, service pumps are not required;

      (iv) an elevated storage capacity of 100 gallons per connection or a pressure tank capacity of 20 gallons per connection. If pressure tanks are used, a maximum capacity of 30,000 gallons is sufficient for up to 2,500 connections. An elevated storage capacity of 100 gallons per connection is required for systems with more than 2,500 connections. Alternate methods of pressure maintenance may be proposed and will be approved if the criteria contained in subsection (g)(5) of this section are met; and

      (v) emergency power for systems which serve more than 250 connections and do not meet the elevated storage requirement. Sufficient emergency power must be provided to deliver a minimum of 0.35 gpm per connection to the distribution system in the event of the loss of normal power supply. Alternately, an emergency interconnection can be provided with another public water system that has emergency power and is able to supply at least 0.35 gpm for each connection in the combined system. Emergency power facilities in systems serving 1,000 connections or greater must be serviced and maintained in accordance with level 2 maintenance requirements contained in the current National Fire Protection Association (NFPA 110 Standard). Although not required, compliance with NFPA 110 Standard is highly recommended for systems serving less than 1,000 connections. Logs of all emergency power use and maintenance must be maintained and kept on file for a period of not less than three years. These records must be made available, upon request, for executive director review.

    (E) Mobile home parks with a density of eight or more units per acre and apartment complexes which supply fewer than 100 connections without ground storage must meet the following requirements:

      (i) a well capacity of 1.0 gpm per connection; and

      (ii) a pressure tank capacity of 50 gallons per connection with a maximum of 2,500 gallons required.

    (F) Mobile home parks and apartment complexes which supply 100 connections or greater, or fewer than 100 connections and utilize ground storage must meet the following requirements:

      (i) a well capacity of 0.6 gpm per connection. Systems with 250 or more connections must have either two wells or an approved interconnection which is capable of supplying at least 0.35 gpm for each connection in the combined system;

      (ii) a total storage of 200 gallons per connection;

      (iii) at least two service pumps with a total capacity of 2.0 gpm per connection; and

      (iv) a pressure tank capacity of 20 gallons per connection.

  (2) Surface water supplies must meet the following requirements:

    (A) a raw water pump capacity of 0.6 gpm per connection with the largest pump out of service;

    (B) a treatment plant capacity of 0.6 gpm per connection under normal rated design flow;

    (C) transfer pumps (where applicable) with a capacity of 0.6 gpm per connection with the largest pump out of service;

    (D) a covered clearwell storage capacity at the treatment plant of 50 gallons per connection or, for systems serving more than 250 connections, 5.0% of daily plant capacity;

    (E) a total storage capacity of 200 gallons per connection;

    (F) a service pump capacity that provides each pump station or pressure plane with two or more pumps that have a total capacity of 2.0 gpm per connection or that have a total capacity of at least 1,000 gpm and the ability to meet peak hourly demands with the largest pump out of service, whichever is less. For systems which provide an elevated storage capacity of 200 gallons per connection, two service pumps with a minimum combined capacity of 0.6 gpm per connection are required at each pump station or pressure plane;

    (G) an elevated storage capacity of 100 gallons per connection or a pressure tank capacity of 20 gallons per connection. If pressure tanks are used, a maximum capacity of 30,000 gallons is sufficient for systems of up to 2,500 connections. An elevated storage capacity of 100 gallons per connection is required for systems with more than 2,500 connections. Alternate methods of pressure maintenance may be proposed and will be approved if the criteria contained in subsection (g)(5) of this section are met; and

    (H) emergency power for systems which serve more than 250 connections and do not meet the elevated storage requirement. Sufficient emergency power must be provided to deliver a minimum of 0.35 gpm per connection to the distribution system in the event of the loss of normal power supply. Alternately, an emergency interconnection can be provided with another public water system that has emergency power and is able to supply at least 0.35 gpm for each connection in the combined system. Emergency power facilities in systems serving 1,000 connections or greater must be serviced and maintained in accordance with level 2 maintenance requirements contained in the current NFPA 110 Standard. Although not required, compliance with NFPA 110 Standard is highly recommended for systems serving less than 1,000 connections. Logs of all emergency power use and maintenance must be maintained and kept on file for a period of not less than three years. These records must be made available, upon request, for executive director review.

  (3) Any community public water system that is an affected utility shall have an emergency preparedness plan approved by the executive director and must meet the requirements for emergency operations contained in subsection (h) of this section. This includes any affected utility that provides 100 gallons of elevated storage capacity per connection.

(c) Noncommunity water systems serving transient accommodation units. The following water capacity requirements apply to noncommunity water systems serving accommodation units such as hotel rooms, motel rooms, travel trailer spaces, campsites, and similar accommodations.

  (1) Groundwater supplies must meet the following requirements.

    (A) If fewer than 100 accommodation units without ground storage, the system must meet the following requirements:

      (i) a well capacity of 1.0 gpm per unit; and

      (ii) a pressure tank capacity of ten gallons per unit with a minimum of 220 gallons.

    (B) For systems serving fewer than 100 accommodation units with ground storage or serving 100 or more accommodation units, the system must meet the following requirements:

      (i) a well capacity of 0.6 gpm per unit;

      (ii) a ground storage capacity of 35 gallons per unit;

      (iii) two or more service pumps which have a total capacity of 1.0 gpm per unit; and

      (iv) a pressure tank capacity of ten gallons per unit.

  (2) Surface water supplies, regardless of size, must meet the following requirements:

    (A) a raw water pump capacity of 0.6 gpm per unit with the largest pump out of service;

    (B) a treatment plant capacity of 0.6 gpm per unit;

    (C) a transfer pump capacity (where applicable) of 0.6 gpm per unit with the largest pump out of service;

    (D) a ground storage capacity of 35 gallons per unit with a minimum of 1,000 gallons as clearwell capacity;

    (E) two or more service pumps with a total capacity of 1.0 gpm per unit; and

Cont'd...

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