§ 33A-5. Basin Management Objectives.

(a)

Basin Management Objectives shall be established for:

(1)

Groundwater elevation;

(2)

Groundwater quality (temperature, pH and electrical conductivity); and

(3)

Land subsidence.

(b)

BMOs shall be based on criteria utilizing data collected from the monitoring network.

(c)

BMO Groundwater Elevation Criteria. One (1) of the following methodologies shall be used to determine the groundwater elevation BMO for wells selected as part of the monitoring network:

(1)

Historic Range Method: This method is used to establish two BMOs for each well based on spring and fall data, seventeen (17) respectively.

i.

For wells that have a period of record dating back to at least 1970, the BMO will be based on the historic low groundwater elevation measurement plus twenty (20) percent of the range in measured groundwater elevations, calculated from the first year on record through 2006.

a.

The BMO Alert Stage 1 will be reached for measurements below the BMO.

b.

The BMO Alert Stage 2 will be reached if measurements are below the historic low.

ii.

For wells that do not have a period of record dating back to 1970, the BMO will be based on the historic low groundwater elevation measurement taken prior to 2006.

a.

The BMO Alert Stage 1 will be reached for measurements below the BMO.

b.

The BMO Alert Stage 2 will be reached for measurements below the historic low minus the range of measurements for the period of record through 2006.

(2)

Specific Depth Method: The BMO will be set at five (5) feet below the average spring groundwater elevation, where the average spring elevation is calculated from the first year on record through 2006.

i.

The BMO Alert Stage 1 will be reached if measurements are below the established BMO for that well.

ii.

The BMO Alert Stage 2 will be reached if BMO Alert Stage 1 continues for a second consecutive year.

iii.

The BMO Alert Stage 3 will be reached if groundwater levels fall ten (10) feet or more below the average spring groundwater elevation established for the well.

(d)

BMO Groundwater Quality Criteria.

(1)

The BMO Alert Stage for temperature will be reached when the measurement is more than five (5) degrees outside of the historic range of measurements.

(2)

The BMO Alert Stage for electrical conductivity (EC uS) will be reached for measurements greater than nine hundred (900) for drinking water or greater than seven hundred (700) for agricultural water.

(3)

The BMO Alert Stage for pH will be reached for measurements below six and one-half (6.5) or above eight and one-half (8.5).

(e)

BMO Land Subsidence Criteria.

(1)

Alert Stage 1 will be reached if annual elastic subsidence exceeds the average annual elastic subsidence measured over the period of record of the extensometer.

(2)

Alert Stage 2 is reached when the annual elastic subsidence exceeds the maximum recorded elastic subsidence over the period of record for the extensometer.

(3)

Alert Stage 3 is reached when inelastic subsidence is detected based on annual measurements taken on March 1.

(Ord. No. 4034, § 1, 9-13-11; Ord. No. 4074, § 1, 1-14-14)