Alaska Admin. Code tit. 18, § 80.605 – Groundwater under the direct influence of surface water (GWUDISW) determination

(a) The owner of an existing or proposed public water system shall provide the information that the department considers necessary to make a determination whether to classify a water source, including a well, spring, or infiltration gallery, as groundwater under the direct influence of surface water (GWUDISW).
(b) The department will determine whether the water source should be classified as GWUDISW based on an evaluation of the information described in (c) of this section. A field assessment as described in (d) of this section, a water quality assessment described in (e) of this section, or both, may also be required before the department makes the determination.
(c) The department will determine if a water source is GWUDISW after an evaluation of information that the department considers necessary to make that determination, including
1. (1) the plans submitted under 18 AAC 80.205;
2. (2) characteristics of the physical area of the water source and area surrounding the water source, including
  1. (A) the horizontal and vertical distance from the water source to surface water, including intermittent surface water;
  2. (B) the topography of the area surrounding the water source, including whether drainage of surface water is directed away from the water source;
  3. (C) relative elevations of source water compared to surface water elevations;
  4. (D) possible sources of biological contamination that could affect water quality, including the location and type of waste disposal and wastewater discharges, if any;
  5. (E) other potential pathways for surface water to infiltrate the subsurface such as wells, holes, and excavations that are not sealed, protected, or filled in accordance with 18 AAC 80.015(d); and
  6. (F) if available, other hydrological or hydrogeological information prepared by a registered engineer or a professional geologist specializing in hydrology or hydrogeology;
3. (3) the construction records of the water source, including
  1. (A) for a well, construction records of the well, including the information required in 18 AAC 80.210(h); or
  2. (B) for a water source other than a well, construction records demonstrating how the water source is protected from surface runoff;
4. (4) the current physical condition of the water source, including
  1. (A) for a well, evidence of how the wellhead complies with 18 AAC 80.015; or
  2. (B) other evidence of how the water source is currently protected from surface water runoff or flooding;
5. (5) the results of laboratory analyses of untreated water from the water source for biological quality or other water quality parameters useful for comparing the water source to surface water, including the results of any advanced water testing methods and analyses, if required by the department under (e) of this section;
6. (6) the occurrence of waterborne disease outbreaks, if any;
7. (7) information from past sanitary surveys, if any;
8. (8) if required by the department, information gathered during an on-site field assessment described in (d) of this section;
9. (9) if required by the department, information contained in the water quality assessment described in (e) of this section; and;
10. (10) additional information needed by the department to make its determination.
(d) The department may require an on-site field assessment to collect information in (c) of this section that is not provided by the owner. The field assessments may be
1. (1) completed by the department, after payment of the fee in 18 AAC 80.1910(a)(5)(A); or
2. (2) completed by a registered engineer, professional geologist, or professional hydrologist, provided to the department in a format approved by the department, and reviewed by the department, after payment of the fee in 18 AAC 80.1910(a)(5)(B).
(e) The department may require the owner to complete a water quality assessment to compare physical, biological, and chemical characteristics of the water source to climatological or surface water conditions, to support a determination as described in (f)(5) of this section. The owner shall
1. (1) before sampling or analysis, submit for department approval a water quality assessment plan that includes
  1. (A) the purpose of the assessment;
  2. (B) the scope of water sources and surface water to be included in the study;
  3. (C) the water quality and other parameters to be measured, such as turbidity, temperature, conductivity, pH, total dissolved solids, microscopic analysis, coliform analysis, or precipitation events;
  4. (D) if necessary, advanced water testing methods and analyses to be used such as
    1. (i) microscopic analysis of the particulate matter in a water sample for primary surface water indicators, including algae, diatoms, Cryptosporidium, and Giardia;
    2. (ii) a particle count analysis that examines the number and size of particles in the surface water body and compares that data to the number and size of particles in water from the source being evaluated;
    3. (iii) an examination of the water for specific chemical tracers that indicate a surface water contaminant;
    4. (iv) specialized analyses, such as examining the source water and surface water for specific ionic ratios, or comparing the source water to other known groundwater sources; or
    5. (v) tracers, dyes, or other tests that the department determines will provide data helpful to the department's determination;
  5. (E) a description of sampling procedures to ensure representative samples, equipment to be used, and corresponding sample locations, frequency, and times;
  6. (F) a description of the anticipated procedures to be used for the data evaluation, interpretation, and criteria to be used as a basis for findings; and
  7. (G) the identification and qualification of personnel responsible for the water quality assessment and personnel participating in the activities proposed for the assessment;
2. (2) present all data collected in the assessment in a format approved by the department, including a written interpretation of the results or findings; and
3. (3) pay the fee required in 18 AAC 80.1910(a)(5)(C), after which the department will review the water quality assessment.
(f) The department will classify the water source as GWUDISW if
1. (1) after the evaluation described in (c) of this section, the department determines that the water source is not protected from direct surface water influence;
2. (2) well construction does not comply with 18 AAC 80.015 to the extent that surface water or surface contamination can directly contaminate the well water, and the owner fails to take the steps required by the department to bring the well into compliance;
3. (3) the water source is not protected from surface runoff or influence, and the owner fails to take the steps required by the department to remedy the deficiency;
4. (4) after review of the on-site field assessment described in (d) of this section, the department determines that the water source is not protected from direct surface water influence; or
5. (5) after review of the water quality assessment described in (e) of this section, the department determines that the water source has
  1. (A) biological surface water indicators;
  2. (B) significant and relatively rapid shifts in water source characteristics; or
  3. (C) other characteristics that closely correlate to climatological or surface water conditions.
(g) The department may require a new GWUDISW determination if it determines that the water source may not be protected from surface water, surface influence, or surface contamination, as a result of changes to the characteristics of the physical area, the physical condition of the water source, the water quality, or other risk factor.
(h) The department will keep a written record of each GWUDISW determination that the department makes, and will retain that record for 40 years after the date of the determination.