(a) Applicability. The requirements of this section apply to community and nontransient, noncommunity public water systems. These regulations establish requirements for monitoring, reporting, corrosion control studies and treatment, source water treatment, lead service line replacement, and public education. Public water systems must control the levels of lead and copper in drinking water by controlling the corrosivity of the water. New water systems will be required to meet the requirements of this section when notified by the executive director.
(b) Compliance levels and ranges. Community and nontransient, noncommunity systems must meet designated lead and copper levels and water quality parameter ranges.
  (1) Lead and copper action levels. Public water systems must meet action levels for lead and copper in drinking water.
    (A) Lead action level. The lead action level is 0.015 milligrams per liter (mg/L). The action level is exceeded if the "90th percentile" lead level exceeds 0.015 mg/L in any monitoring period. The 90th percentile lead level is exceeded when more than 10% of tap water samples have a concentration over the action level.
    (B) Copper action level. The copper action level is 1.3 mg/L. The action level is exceeded if the concentration of copper in more than 10% of tap water samples collected during any monitoring period is greater than 1.3 mg/L.
  (2) Reduced lead and copper monitoring levels. Systems with levels of lead and copper less than the reduced monitoring levels may be eligible for reduced monitoring under subsections (c) - (e) of this section.
    (A) The reduced monitoring level for lead is 0.005 mg/L.
    (B) The reduced monitoring level for copper is 0.65 mg/L.
    (C) A system with 90th percentile levels of lead and copper less than or equal to the reduced monitoring levels in two consecutive six-month initial or routine tap sampling periods may be eligible for reduced monitoring under subsections (c) - (e) of this section.
  (3) Lead and copper Practical Quantitation Levels (PQLs). The PQLs for lead and copper are defined by this paragraph.
    (A) The PQL for lead is 0.005 mg/L.
    (B) The PQL for copper is 0.050 mg/L.
  (4) Optimal water quality parameter (OWQP) ranges. The executive director shall set approved OWQP ranges for systems based on corrosion control studies described in subsection (f)(1) of this section. All systems that exceed an action level for lead or copper based on the 90th percentile are required to have approved OWQP ranges. Systems that serve more than 50,000 people that exceed the PQL for lead based on the 90th percentile are required to have approved OWQP ranges. Systems with approved water quality parameter ranges shall operate within the approved OWQP ranges at all times.
    (A) OWQP ranges shall include all elements contained in this subparagraph.
      (i) OWQPs shall include a minimum value or a range of values for negative log of hydrogen ion concentration (pH) measured at each entry point to the distribution system.
      (ii) OWQPs shall include a minimum pH value, measured in all tap samples. Such value shall be equal to or greater than 7.0, unless the executive director determines that meeting a pH level of 7.0 is not technologically feasible or is not necessary for the system to optimize corrosion control.
      (iii) If a corrosion inhibitor is used, OWQPs shall include a minimum concentration or a range of concentrations for the inhibitor, measured at each entry point to the distribution system and in all tap samples, that the executive director determines is necessary to form a passivating film on the interior walls of the pipes of the distribution system.
      (iv) If alkalinity is adjusted as part of optimal corrosion control treatment, OWQPs shall include a minimum concentration or a range of concentrations for alkalinity, measured at each entry point and in all distribution samples.
      (v) If calcium carbonate stabilization is used as part of corrosion control, OWQPs shall include a minimum concentration or a range of concentrations for calcium, measured in all distribution samples.
    (B) Systems that must perform corrosion controls studies under subsection (f) of this section shall submit proposed system-specific OWQP ranges in writing for the executive director's approval.
    (C) The executive director shall review and designate OWQPs in writing within six months after receipt of the system's recommended OWQPs.
  (5) Deemed to have optimized corrosion control. A system may be considered deemed to have optimized corrosion control if it meets the requirements of this paragraph.
    (A) A system that serves 50,000 or fewer people may be deemed to have optimized corrosion control if the system meets the lead and copper action levels in two consecutive initial or routine monitoring periods.
    (B) A system that serves more than 50,000 people may be deemed to have optimized corrosion control if the difference between the 90th percentile lead level and the highest entry point lead level is less than the PQL and the system meets the copper action levels in two consecutive initial or routine monitoring periods.
    (C) Those systems whose highest source water lead level is below the method detection limit may also be deemed to have optimized corrosion control under this paragraph if the 90th percentile tap water lead level is less than or equal to the PQL for lead for two consecutive six-month monitoring periods.
    (D) Any water system may be deemed by the executive director to have optimized corrosion control treatment if the system demonstrates, to the satisfaction of the executive director, that it has conducted activities equivalent to the corrosion control requirements of this section, including all applicable monitoring requirements.
    (E) Any system that fails to perform required monitoring or reporting, operates outside any approved OWQP ranges, or exceeds a lead or copper action level shall no longer be deemed to have optimized corrosion control.
  (6) Maximum permissible levels (MPLs) for source water lead. The executive director shall designate MPLs for lead and copper at entry points to the distribution system for systems that are required to install source water treatment under subsection (g) of this section. Such MPLs shall reflect the contaminant-removal capability of the source water treatment properly operated and maintained. The executive director shall determine MPLs based on source water samples taken by the water system before and after the system installs the approved source water treatment. The executive director will set MPLs in writing, explaining the basis of that decision, within six months after the system completes follow-up tap sampling for lead and copper after source water treatment installation under subsection (g) of this section.
(c) Lead and copper tap sampling locations and frequency. Community and nontransient, noncommunity public water systems shall sample at sites approved by the executive director and at a frequency set by the executive director. Systems shall conduct initial tap sampling until the system either exceeds the lead or copper action level or becomes eligible for reduced monitoring.
  (1) Lead and copper tap sampling locations. Systems shall sample at sites approved by the executive director and documented in the system's monitoring plan required under §290.121 of this title (relating to Monitoring Plans).
    (A) Number of tap sample sites. The minimum number of sample sites required for initial, routine, or reduced lead and copper tap sampling are listed in the following table, entitled "Required Number of Lead and Copper Tap Sample Sites:"
Attached Graphic
    (B) Suitable sample taps. All sites from which lead and copper tap samples are collected shall be selected from a pool of targeted sampling sites identified through a materials survey of the distribution system. Sample sites shall be selected first at tier 1, then tier 2, then tier 3 locations as defined in subparagraph (D) of this paragraph. Sampling sites may not include faucets that have point-of-use or point-of-entry treatment devices designed to remove inorganic chemicals.
    (C) Material survey and sample site selection form. Sample sites shall be representative of the distribution system and specifically represent areas of the system most vulnerable to corrosion of lead and copper into the water. The system must maintain a current copy of their Material Survey Form with the monitoring plan.
      (i) Material survey. Systems shall perform a materials survey to select sample appropriate tap sampling sites using the Material Survey Form and Instructions (TCEQ Form Number 20467). The material survey shall be submitted in writing for executive director review and approval. In performing the material survey, the system shall review the sources of information listed in this clause in order to identify sampling sites. In addition, the system shall seek to collect such information where possible in the course of its Cont'd...