N.H. Code Admin. R. Env-Ws 382.07

Current through Register No. 25, June 20, 2024

Section Env-Ws 382.07 - Monitoring Requirements

(a) All samples collected pursuant to this part shall be collected under normal operating conditions.

(b) Multiplewells for which a disinfectant is injected at a single treatment plant shall be considered as one treatment plant for determining the minimum number of TTHM and HAA5 samples required as specified in Env-Ws 382.08.

(c) Multiplewells for which a disinfectant is added at multiple separate points shall be considered as one treatment plant for determining the minimum number of TTHM and HAA5 samples specified in Env-Ws 382.08, in accordance with the following criteria:

(1) Routine monitoring at a frequency specified in Env-Ws 382.08 shall have been performed for a minimum of one year;

(2) Running annual average results shall be less than 0.040 mg/L for TTHM and 0.030 mg/L for HAA5;

(3) For overburden wells, multiple wells shall be located within the same aquifer as determined using the stratified drift aquifer mapping of the U.S. Geological Survey;

(4) For bedrock wells, multiple wells shall be located within an area of less than 4000 feet in radius; and

(5) The water quality of the multiple wells shall be within the following limits:

a. pH within 0.5 units, using one of the analytical methods specified in 40 CFR 141.23(k);

b. Total hardness within 10 mg/L, as CaCO₃;

c. Alkalinity within 10 mg/L, as CaCO₃; and

d. Conductivity within 50 umhos/cm².

(d) If running annual average results for multiple wells initially considered as one treatment plant in (c) above, subsequently exceed 0.040 mg/L for TTHM and 0.030 mg/L for HAA5, each well shall then be considered as a separate treatment plant for monitoring purposes, subject to the routine and reduced monitoring frequency requirements specified in Env-Ws 382.08 and Env-Ws 382.09.

(e) The failure to monitor shall be considered a violation for the entire period covered by the annual average where:

(1) Compliance is based on a running annual average of monthly or quarterly samples or averages; and

(2) The system owner's failure to monitor makes it impossible to determine compliance with MCLs or MRDLs.

(f) To qualify for reduced monitoring, a system owner shall use only data collected under the provisions of 40 CFR 141, Subpart M, July 1, 2000 edition.

N.H. Code Admin. R. Env-Ws 382.07

(See third Revision Note at chapter heading Env-Ws 300); #7735, eff 8-2-02