(a) Septic tank effluent filters. Effective 180 days after the effective date of these rules, all effluent filters that are installed in septic tanks shall be listed and approved under the NSF International Standard 46 (2000) or under any standard approved by the executive director.     
      (b) Pump tanks. Pump tanks may be necessary when the septic tank outlet is at a lower elevation than the disposal field or for systems that require pressure disposal. All requirements in §285.32(b)(1)(D) - (F) of this title (relating to Criteria for Sewage Treatment Systems) also apply to pump tanks. The pump tank shall be constructed according to the following specifications.      
        (1) Pump tank criteria. When effluent must be pumped to a disposal area, an appropriate pump shall be placed in a separate water-tight tank or chamber. A check valve may be required if the disposal area is above the pump tank. The pump tank shall be equipped to prevent siphoning. The tank shall be provided with an audible and visible high water alarm. If an electrical alarm is used, the power circuit for the alarm shall be separate from the power circuit for the pump. Batteries may be used for back-up power supply only. All electrical components shall be listed and labeled by Underwriters Laboratories (UL). At the discretion of the permitting authority, leak testing using water filled to the inside level of the tank lid or to the top of the riser(s) may be required.       
        (2) Pump tank sizing. Pump tanks shall be sized to contain one-third of a day's flow between the alarm-on level and the inlet to the pump tank. The capacity above the alarm-on level may be reduced to four hours average daily flow if the pump tank is equipped with multiple pumps. See §285.33(d)(2)(G)(iii) of this title (relating to Criteria for Effluent Disposal Systems) for sizing of pump tanks for surface application systems.       
        (3) Pump specifications. A single pump may be used for hydraulic flows equal to or less than 1,000 gallons per day. Dual pumps are required for hydraulic flows greater than 1,000 gallons per day. A dual pump system shall have the "alarm on" level below the "second pump on" level, and shall have a lock-on feature in the alarm circuit so that once it is activated it will not go off when the second pump draws the liquid level below the "alarm on" level. All audible and visible alarms shall have a manual "silence" switch. The pump switch-gear shall be set such that each pump operates as the first pump on an alternating basis. All pumps shall be rated by the manufacturer for pumping sewage or sewage effluent.       
        (4) Equalization tanks. In addition to the requirements for pump tanks in this section, equalization tanks shall meet the following criteria:                  (A) The equalization tank must be preceded by a pretreatment tank.                   (B) If an equalization tank is serving residences, the tank shall have a volume between the pump intake level and the high water level of at least 50% of the design flow and be designed to time dose at equal intervals and equal doses throughout a 24-hour period. The tank may contain a gravity line located above the high water alarm level which allows flow to the aerobic treatment unit. The design will use no fewer than 12 doses throughout the 24-hour period.                   (C) If an equalization tank is designed to equalize flows over periods longer than a 24-hour period, the tank shall be designed to time dose at equal intervals and equal doses over the flow equalization time period. The design shall have a storage between the highest wastewater flow line during the period and the high level alarm equal to at least 20% of the flow generated during peak days. The tank may contain a gravity line located above the high water alarm level which allows flow to the aerobic treatment unit.         
      (c) Electrical wiring. All electrical wiring and their conduits shall conform to the requirements of the National Electric Code (1999) or under any other standards approved by the executive director. Additionally, all external wiring shall be installed in approved, rigid, non-metallic gray code electrical conduit. The conduit shall be buried according to the requirements in the National Electrical Code and terminated at a main circuit breaker panel or sub-panel. The permitting authority may approve up to four feet of external wiring to be contained in water-tight, flexible electrical conduit between the buried wire and the circuit breaker panel or sub-panel. Any external wiring that exceeds four feet must be contained in rigid, non-metallic gray code electrical conduit. Connections shall be in approved junction boxes. All electrical components shall have an electrical disconnect within direct vision from the place where the electrical device is being serviced. Electrical disconnects must be weatherproof (approved for outdoor use) and have maintenance lockout provisions.     
      (d) Grease interceptors. Grease interceptors shall be used on kitchen waste-lines from institutions, hotels, restaurants, schools with lunchrooms, and other buildings that may discharge large amounts of greases and oils to the OSSF. Grease interceptors shall be structurally equivalent to, and backfilled according to, the requirements established for septic tanks under §285.32(b)(1)(D) - (F) of this title. The interceptor shall be installed near the plumbing fixture that discharges greasy wastewater and shall be easily accessible for cleaning. Grease interceptors shall be cleaned out periodically to prevent the discharge of grease to the disposal system. Grease interceptors shall be properly sized and installed according to the requirements of the 2000 edition of the Uniform Plumbing Code, the 1980 EPA Design Manual: Onsite Wastewater Treatment and Disposal Systems, or other prevailing code.     
      (e) Holding tanks. Tanks shall be constructed according to the requirements established for septic tanks under §285.32(b)(1)(D) - (E) of this title. Inlet fittings are required. No outlet fitting shall be provided. A baffle is not required. Holding tanks shall be used only on sites where other methods of sewage disposal are not feasible (these holding tank provisions do not apply to portable toilets or to an office trailer at a construction site). All holding tanks shall be equipped with an audible and visible alarm to indicate when the tank has been filled to within 75% of its rated capacity. A port with its smallest dimension being at least 12 inches shall be provided in the tank lid for inspection, cleaning, and maintenance. This port shall be accessible from the ground surface and must be easily removable and watertight.      
        (1) Minimum capacity. The minimum capacity of the holding tank shall be sufficient to store the estimated or calculated daily wastewater flow for a period of one week (wastewater usage rate in gallons per day x seven days).       
        (2) Location. Holding tanks shall be installed in an area readily accessible to a pump truck under all weather conditions, and at a location that meets the minimum distance requirements in §285.91(10) of this title (relating to Tables).       
        (3) Pumping requirements. A scheduled pumping contract with a waste transporter, holding a current registration with the executive director, must be provided to the permitting authority before a holding tank may be installed. Pumping records must be retained for five years.       
      (f) Composting toilets. Composting toilets will be approved by the executive director provided the system has been tested and certified under NSF International Standard 41 (1999) or under any other standards approved by the executive director.     
      (g) Condensation. If condensate lines are plumbed directly into an OSSF, the increased water volume must be accounted for (added to the usage rate) in the system planning materials.     
     Source Note:        The provisions of this §285.34 adopted to be effective February 5, 1997, 22 TexReg 1114; amended to be effective June 13, 2001, 26 TexReg 4115; amended to be effective September 11, 2008, 33 TexReg 7536; amended to be effective December 27, 2012, 37 TexReg 9947; amended to be effective July 6, 2023, 48 TexReg 3508