(6) DWSP Delineation Report - Each PWS shall
submit a DWSP Delineation Report to DDW for each of its groundwater sources
using the Preferred Delineation Procedure or the Optional Two-Mile Radius
Delineation Procedure.
(a) Preferred
Delineation Procedure - Delineation reports for protection zones delineated
using the Preferred Delineation Procedure shall include the following
information and a list of sources or references for this information:
(i) Geologic Data - A brief description of
geologic features and aquifer characteristics observed in the well and area of
the potential protection zones. This should include the formal or informal
stratigraphic name lithology of the aquifer and confining unit, and description
of fractures and solution cavities, including the size, abundance, spacing, and
orientation; and faults, including a brief description of location in or near
the well, and orientation. Lithologic descriptions can be obtained from surface
hand samples or well cuttings; core samples and laboratory analyses are not
necessary. Fractures, solution cavities, and faults may be described from
surface outcrops or drill logs.
(ii) Well Construction Data - If the source
is a well, the report shall include the well driller's log, elevation of the
wellhead, borehole radius, casing radius, total depth of the well, depth and
length of the screened or perforated interval, well screen or perforation type,
casing type, method of well construction, type of pump, location of pump in the
well, and the maximum projected pumping rate of the well. The maximum pumping
rate of the well must be used in the delineation calculations. Averaged pumping
rate values shall not be used.
(iii) Spring Construction Data - If the
source is a spring or tunnel the report shall include a description or diagram
of the collection area and method of groundwater collection.
(iv) Aquifer Data for New Wells - A summary
report including the calculated hydraulic conductivity of the aquifer,
transmissivity, hydraulic gradient, direction of groundwater flow, estimated
effective porosity, and saturated thickness of the producing aquifer. The PWS
shall obtain the hydraulic conductivity of the aquifer from a constant-rate
aquifer test and provide the data as described in Subsection R309-515-6(10)(b).
Estimated effective porosity must be between 1% and 30%. Clay layers shall not
be included in calculations of aquifer thickness or estimated effective
porosity. This report shall include graphs, data, or printouts showing the
interpretation of the aquifer test.
(v) Aquifer Data for Existing Wells - A
summary report including the calculated hydraulic conductivity of the aquifer,
transmissivity, hydraulic gradient, direction of groundwater flow, estimated
effective porosity, and saturated thickness of the producing aquifer. The PWS
shall obtain the hydraulic conductivity of the aquifer from a constant-rate
aquifer test using the existing pumping equipment. Aquifer tests using
observation wells are encouraged but are not required. If a previously
performed aquifer test is available and includes the required data described in
Subsection R309-600-9(6)(v)(A) and Subsection R309-600-9(6)(v)(B), data from
that test may be used instead. Estimated effective porosity must be between 1%
and 30%. Clay layers shall not be included in calculations of aquifer thickness
or estimated effective porosity. This report shall include graphs, data, or
printouts showing the interpretation of the aquifer test.
If a constant-rate aquifer test is not practical, then the
PWS shall obtain hydraulic conductivity of the aquifer using another
appropriate method, such as data from a nearby well in the same aquifer,
specific capacity of the well, published hydrogeologic studies of the same
aquifer, or local or regional groundwater models. A constant-rate test may not
be practical for such reasons as insufficient drawdown in the well,
inaccessibility of the well for water-level measurements, or insufficient
overflow capacity for the pumped water.
The constant-rate test shall:
(A) Provide for continuous pumping for at
least 24 hours or until stabilized drawdown has continued for at least six
hours. Stabilized drawdown is achieved when there is less than one foot of
change of groundwater level in the well within a six-hour period.
(B) Provide data as described in Subsections
R309-515-6(10)(b)(v) through (vii).
(vi) Additional Data for Observation Wells -
If the aquifer test is conducted using observation wells, the report shall
include the following information for each observation well: location and
surface elevation; total depth; depth and length of the screened or perforated
intervals; radius, casing type, screen or perforation type, and method of
construction; pre-pumping groundwater level; the time-drawdown or
distance-drawdown data and curve; and the total drawdown.
(vii) Hydrogeologic Methods and Calculations
- These include the groundwater model or other hydrogeologic methods used to
delineate the protection zones, any applicable equations, values, and the
calculations which determine the delineated boundaries of zones two, three, and
four. The hydrogeologic method or groundwater model must be reasonably
applicable for the aquifer setting. For wells, the hydrogeologic method or
groundwater model must include the effects of drawdown, including increased
hydraulic gradient near the well, and interference from other wells.
(viii) Map Showing Boundaries of the DWSP
Zones - A map showing the location of the groundwater source of drinking water
and the boundary for each DWSP zone. The base map shall be a 1:24,000-scale,
7.5-minute series, topographic map, such as is published by the US Geological
Survey. Although zone one, 100-foot radius around the well or margin of the
collection area, need not be on the map, the complete boundaries for zones two,
three, and four must be drawn and labeled. More detailed maps are optional and
may be submitted in addition to the required map.
The PWS shall also include a written description of the
distances which define the delineated boundaries of zones two, three, and four.
These written descriptions must include the maximum distances upgradient from
the well, the maximum distances downgradient from the well, and the maximum
widths of each protection zone.
(b) Optional Two-Mile Radius Delineation
Procedure -Delineation Reports for protection areas delineated using the
Optional Two-Mile Radius Delineation Procedure shall include the following
information:
(i) Map Showing Boundaries of the
DWSP Management Area - A map showing the location of the groundwater source of
drinking water and the DWSP management area boundary. The base map shall be a
1:24,000-scale, 7.5-minute series, topographic map, such as is published by the
US Geological Survey. Although zone one, 100-foot radius around the well or
margin of the collection area, need not be on the map, the complete two-mile
radius must be drawn and labeled. More detailed maps are optional and may be
submitted in addition to the required map.
(ii) Hydrogeologic Report to Exclude a
Potential Contamination Source - To exclude a potential contamination source
from the inventory which is required in Subsection R309-600-10(1), a
hydrogeologic report is required which clearly demonstrates that the potential
contamination source has no capacity to contaminate the source.
