9.1 Excessive sediment standards. The following standards shall be used to determine when excessive sediment exists in a well. Excessive sediment will be determined using EPA Test Method 160.5 (Imhoff Cone). Amounts in excess of the below standards are considered excessive.
1. 1 mg/liter -- water to be used directly in contact with, or in the processing of, food and beverages.
2. 5 mg/liter -- water for homes, institutions, municipalities, and industries.
3. 10 mg/liter -- water for sprinkler irrigation systems, industrial evaporative cooling systems, and any other use where a moderate amount of sediment is not especially harmful.
4. 15 mg/liter -- water for flood-type irrigation
9.2 Arkansas Water Well Construction Commission Excessive Sediment Protocol. When determining whether a well produces excessive sediment in accordance with the above standards, Commission staff shall use the following procedure for collecting samples.
9.2.1 Routine water well inspections. Routine water well inspections for which no specific complaint of excessive sediment has been received shall include the following sampling process using EPA Test Method 160.5 (Imhoff Cone) and USGS approved 500 ml sample bottles:
1. The well shall be purged by three (3) volumes of water,
2. Five (5) samples shall be collected over a two (2) hour period, spaced at a minimum of twenty (20) minute intervals,
3. Sediment volume shall be estimated from all five (5) samples and averaged to determine the amount of sediment produced by the well, and
4. Data shall be recorded on an AWWCC inspection form.
If it is determined that the sediment amount exceeds 5 mg/L, the AWWCC staff member shall follow the protocol outlined in 9.2.1.2.
9.2.1.2 [FN1] Investigation of excessive sediment complaints or wells that produce more than 5 mg/L of sediment. If a complaint of excessive sediment is received, or if a routine well inspection reveals that a well is producing more than 5 mg/L of sediment, the following sampling process using EPA Test Method 160.5 (Imhoff Cone) and USGS approved 500 ml sample bottles shall be followed:
1. Staff inspectors shall coordinate with an ANRC registered geologist or engineer who has been trained in water quality data collections. These two individuals will conduct the sampling of the well in question,
2. The well shall be purged by three (3) volumes,
3. Five (5) samples shall be collected over a two (2) hour period, spaced at a minimum of twenty (20) minute intervals,
4. At the time of sampling, a data collection sheet shall be completed. The data collection sheet shall include, at a minimum:
a. Date,
b. Time each sample was collected,
c. Well location to include longitude and latitude,
d. Well owner information,
e. Location where the sample was taken (i.e. faucet in the home, etc.),
f. Photos, if possible,
g. Aquifer information, and
h. General description of the area including a site sketch if possible,
5. All efforts to prevent sample contamination shall be used to include the use of the USGS approved 500 ml sample bottles. After the samples are collected, the bottles are to be sealed and labeled with the date and the initials of the person collecting the sample, and
6. Following the sealing of the samples, a “Chain of Custody” form shall be completed by the employee who completed the sampling and shall include:
a. Information from the data collection sheets,
b. Names of the personnel collecting the samples,
c. Name and Location of the lab the sample was taken to,
d. Initials of the lab personnel who accepted delivery of the samples, and
7. Samples shall be placed on ice and kept at cool temperatures until they are delivered to a qualified water quality testing laboratory. The samples shall be delivered to a qualified laboratory within seventy-two (72) hours of collection.
8. Sediment volume shall be estimated from all five (5) samples and averaged to determine the amount of sediment produced by the well using EPA Test Method 160.5
Credits
Amended Aug. 1, 2009; June 3, 2016; June 1, 2018; Sept. 5, 2020.
[FN1]
So in original.
Current with amendments received through February 15, 2024. Some sections may be more current, see credit for details.
