Section 329 IAC 10-15-4 - Hydrogeologic site investigation reportAuthority: IC 13-14-8-7; IC 13-15; IC 13-19-3
Affected: IC 13-18; IC 13-20; IC 36-9-30
Sec. 4.
(a) A permit application for a new MSWLF or a lateral expansion must be accompanied by a written hydrogeologic site investigation report that must describe the regional and site specific hydrogeology and must, at a minimum, include sufficient hydrogeologic information to allow the commissioner to do the following: (1) Determine the suitability of the site for solid waste disposal.(2) Identify and characterize: (A) the hydrogeology of the uppermost aquifer system;(B) all geologic strata that exist above the uppermost aquifer system; and(C) the geologic strata defining the lower boundary of the uppermost aquifer.(3) Characterize the site geology to allow for the evaluation of the proposed design of the proposed MSWLF unit and to ensure that it will be in compliance with the requirements of 329 IAC 10-16-9 and 329 IAC 10-17-2.(4) Determine the hydrogeologic conditions and the relationship to the proposed MSWLF unit in order to predict pollutant movement in the event of releases from the proposed MSWLF unit.(5) Determine the adequacy of the proposed monitoring well system to provide early detection by intercepting ground water contaminated by leachate from the proposed MSWLF unit.(b) The hydrogeological site investigation report must include a description, based on publicly available information, of the regional hydrogeology of the proposed MSWLF unit. The report must include the following information pertaining to regional hydrogeology: (1) Demonstration of how the regional hydrogeology relates to the following:(A) The on-site hydrogeologic conditions.(B) The location of nearby sensitive environments.(2) Identification of the regional aquifer and aquifer of significance.(3) Well logs of public and private water supply wells within one (1) mile of the proposed solid waste boundary as available through the division of water files of the department of natural resources or through other publicly accessible sources. If well logs from a dwelling or from an occupied building located within one-fourth (1/4) mile of the proposed solid waste boundary are not publicly available, a summary of results from a survey conducted as required under 329 IAC 10-11-2.5(a)(17) must be submitted in substitution for those well logs.(4) Average yield of water supply wells located within one (1) mile of the proposed solid waste boundary, as determined from well logs on file with the department of natural resources or from other publicly available information.(5) Direction of ground water flow in the regional aquifer and aquifer of significance.(6) Identification of recharge and discharge areas of the regional aquifer and aquifer of significance.(7) Identification of any public water supply system wells within ten (10) miles of the proposed solid waste boundary.(8) Determination of the regional aquifer and aquifer of significance as a confined aquifer or an unconfined aquifer.(9) Identification of aquitard or aquitards and aquiclude or aquicludes.(10) A discussion of regional geologic conditions that must include available and appropriate information to describe the following: (A) Bedrock stratigraphy, represented on maps and columnar diagrams, constructed from field exposures and the geologic literature, describing:(i) formation and member names;(v) the proposed MSWLF unit's mineralogic and geochemical compositions and variabilities;(vii) porosities and bulk permeabilities, including karst development;(viii) orientation, density, and spacing of joints; and(ix) other pertinent features.(B) Glacial geology, including a discussion of:(i) the formation, stages, and distribution of glacial deposits; and(ii) hydrologic characteristics of the surficial deposits, including kames, eskers, and outwash plains.(11) Structural geology, including a description of local and regional structural features.(12) Description of the regional geomorphology, surface water, and ground water hydrologic features, including the following:(A) Surface water drainage patterns.(C) The location of surface water bodies.(F) An analysis of any topographic features that may influence the ground water flow system.(c) The hydrogeological site investigation report must include a description of the site-specific hydrogeology of the proposed MSWLF unit. The site-specific report must include results of field and laboratory investigations that are performed to do the following:(1) Define physical site characteristics, including soils, unconsolidated and consolidated stratigraphy, and ground water.(2) Describe and characterize the ground water quality of the uppermost aquifer system and all significant zones of saturation above the uppermost aquifer system. This report must:(A) include a description and the source of any ground water contamination located under the site; and(B) report data gathered by sampling and analyzing the ground water at least one (1) time from the uppermost aquifer system and all significant zones of saturation above the uppermost aquifer system for, at a minimum, the constituents of Table 1A in 329 IAC 10-21-15(a) and Table 1B in 329 IAC 10-21-15(b).(d) The description of the site-specific hydrogeology must be based on investigations that satisfy, at a minimum, the following requirements:(1) Boreholes and piezometers must be of sufficient numbers to adequately define the soil, pertinent geologic strata, and ground water conditions at the site and must be in accordance with the following: (A) There must be at least one (1) borehole and one (1) piezometer for every five (5) acres of solid waste disposal area, with a minimum of five (5) boreholes and five (5) piezometers at any site.(B) The boreholes must be evenly distributed across the study area and located such that there is one (1) borehole and one (1) piezometer in each major topographic feature, excluding areas inaccessible to drilling equipment, but including the following: (C) Boreholes must be extended at least ten (10) feet below the confining unit defining the lower boundary of the uppermost aquifer or twenty (20) feet into the confining unit, whichever is less.(D) Boreholes may be converted to piezometers to comply with the requirements of this subdivision.(2) Additional boreholes and piezometers, not necessarily meeting the requirements in subdivision (1), may be required by the commissioner to delineate the boundaries of any other features pertinent to the proposed MSWLF unit's design.(3) The screened interval of piezometers and monitoring wells must not exceed ten (10) feet in length.(4) Diagrammatical drilling logs must be recorded for all boreholes and all piezometers, and each log must be of similar scale and include the following: (A) Borehole identification number.(F) Drilling muds and fluids used.(G) Penetration measurements, such as hammer blow counts, penetrometer measurements, or other acceptable penetration measurements.(H) Sample recovery measured in tenths of a foot.(I) Textural classification and descriptions for the entire depth of each borehole and each piezometer.(J) Interval of continuous samples and soil test data.(K) The depths to, and thickness of, any water bearing zones.(L) Water level measurements with dates and times of measurements indicated.(M) The surveyed elevation at the ground surface to the nearest plus or minus one-tenth (±0.1) foot, relative to the National Geodetic Vertical Datum (NGVD), at each borehole and each piezometer. The elevation of the referenced mark located on top of the casing of each ground water monitoring well and piezometer must be surveyed to the nearest plus or minus one-hundredth (±0.01) foot. The referenced mark must be used to measure static water levels.
(N) Horizontal position of each borehole and piezometer using the Universal Transverse Mercator (UTM) system or a site grid coordinate system that can easily be translated into the UTM system. The horizontal position must be surveyed to an accuracy of thirty (30) centimeters.(O) Total borehole depth and elevation.(5) Drilling logs of unconsolidated material must describe the following: (A) Texture, using the United States Department of Agriculture (USDA) textural classification. Grain-size divisions shall be based on a modified form of the Wentworth grain-size scale defined under 329 IAC 10-2-206.3. A determination shall be made of the percentage and grades of coarse fragments greater than two (2) millimeters in size based on 329 IAC 10-2-206.3 in addition to the USDA textural classification.(B) Lithological description.(C) Color as referenced from soil color charts, such as Munsell soil charts.(D) Reaction (effervescence) to dilute ten percent (10%) cold hydrochloric acid (HCL).(F) Sedimentary features, such as the following:(i) Bedding or lamination.(ii) Cross-stratification.(iii) Deformation in bedding.(iv) Bedding surface structures.(v) Fossils and biturbation.(J) Zones of secondary porosity, such as the following:(i) Channels of various origins.(ii) Fractures or soil structure units.(iii) Bedding planes or laminations.(iv) Pores (interstices).(6) Drilling logs of consolidated material must describe the following:(A) Lithology and sedimentology.(C) Degree of cementation.(D) Color as referenced from soil color charts, such as the Munsell soil charts.(F) Any other physical characteristics of the rock, such as scent, staining, fracturing, and solution features.(G) Percent recovery and rock quality designation.(H) Other primary and secondary features.(I) Drilling observations and appropriate details required for unconsolidated drilling logs.(J) A clear and labelled photograph of all labelled cores must be taken and submitted with the drilling logs. The photograph labelling must include the following information: (i) Date photograph was taken.(iv) Reference color scale.(v) Identification of borehole.(7) The diagrammatical construction details of each piezometer must be recorded on the logs and include the following:(A) Piezometer identification number and UTM coordinates.(B) Elevation of the top of the piezometer casing.(C) Height of piezometer casing above the ground.(D) Elevation of the ground surface.(E) Elevation and depth to the bottom of the borehole.(F) Diameter of piezometer casing and borehole.(G) Elevation and depth to the bottom and top of the piezometer screen.(H) Length of piezometer casing. (I) Composition of piezometer casing materials and piezometer screen material.(J) Length of piezometer screen.(L) Type of joints or couplings, or both, between casing segments.(M) Elevation and depth to the top and bottom of the gravel filter pack surrounding the piezometer screen.(N) Length of the gravel filter pack.(O) Elevation and depth of the bottom of the piezometer casing.(P) Elevation and depth of the top and bottom of the seal above the gravel filter pack.(Q) The grain size and composition of all filter pack materials and the fifty percent (50%) retained size of the formation material used to determine filter pack materials.(R) Thickness of the seal above the gravel filter pack.(S) Elevation and depth of the annular seal above the gravel filter pack seal.(T) Thickness of the annular seal.(U) Material used for the annular seal.(V) Method of installation of the annular seal.(W) The composition and design of the surface seal.(8) Samples of unconsolidated and consolidated material must be taken on a continuous basis. For piezometer clusters, continuous samples must be collected from the surface to the base of the deepest piezometer. Other piezometers in the cluster must be sampled at all significant stratigraphic changes and at the screened interval. Samples of different significant stratum must not be combined into composites for textural classification or testing.(9) United States Department of Agriculture (USDA) textural classification must be utilized for describing unconsolidated samples. Grain-size divisions shall be based on a modified form of the Wentworth grain-size scale defined under 329 IAC 10-2-206.3. A determination shall be made of the percentage and grades of coarse fragments greater than two (2) millimeters in size based on 329 IAC 10-2-206.3 in addition to the USDA textural classification. Rock cores or samples must be described and classified using accepted geologic classification systems and nomenclature. A clear description of the classification system used must be included with the logs.(10) Complete grain size analysis, including sieve or hydrometer, or both, as appropriate to the soil type, must be performed on a representative sample from each significant stratum encountered in each borehole for unconsolidated samples.(11) A minimum of three (3) laboratory hydraulic conductivity tests must be conducted for each significant stratum identified beneath the site when samples can be obtained with minimal disturbance. Representative samples must be taken from different boreholes and elevations within each significant stratum. Samples must not be recompacted, and disturbances to samples must be minimized. If samples cannot be obtained with minimal disturbance, the commissioner must be contacted so that a program can be developed so alternative tests can be used to obtain the hydraulic conductivity of the sample.(12) Hydraulic conductivity of the uppermost aquifer and any significant zones of saturation that exist above the uppermost aquifer system must be determined. In situ hydraulic conductivity testing must be done in all piezometers and all monitoring wells. The testing method used must not introduce contaminants into the well. Hydraulic conductivities may be determined using pump tests, slug tests, packer tests, tracer studies, isotopic geochemistry, thermal detection, or other suitable methods as approved by the commissioner.(13) Vertical hydraulic gradients of the uppermost aquifer and of any aquifers below the site that are hydraulically connected to the uppermost aquifer must be measured at a minimum of three (3) separate locations at the site. Additional nested piezometers or wells may be required by the commissioner to adequately determine vertical components.(14) Cation exchange capacity and Atterberg limits tests must be performed on a representative sample from each significant stratum encountered in each borehole in which a piezometer or monitoring well is to be installed. These tests may be waived for a sample if it is demonstrated that the sample is not conducive to these tests.(e) The commissioner may vary the minimum requirements described under subsection (d) where alternate testing methods provide comparable information.(f) All testing and sampling procedures must be identified and all results identified with respect to the borehole and piezometer and depth.(g) Borehole and piezometer samples collected must be retained in labeled containers or core boxes. All samples must be securely stored and accessible for seven (7) years after issuance of the permit. The location of the storage area must be designated.(h) All boreholes, including boreholes that are not converted into piezometers or monitoring wells, and other holes that may cause or facilitate contamination of ground water must be permanently sealed in accordance with the following standards: (1) If not sealed immediately, the borehole must be covered to prevent injury to people or animals.(2) All boreholes and piezometers no longer intended for use must be sealed with neat cement, bentonite, or other materials approved by the commissioner to prevent the creation of a pathway for contaminants to migrate.(3) An accurate record of the sealing materials and procedures must be submitted along with the drilling logs to the commissioner.(i) Ground water monitoring wells installed, replaced, or converted from piezometers after the effective date of this article, must comply with the following:(1) All ground water monitoring wells installed after the effective date of this article must comply with the requirements of 329 IAC 10-21-4.(2) Any piezometers redesigned as monitoring wells after the effective date of this article must meet the requirements of 329 IAC 10-21-4.(3) Except for ground water monitoring wells that are destroyed, or fail to function properly as described in 329 IAC 10-21-1(g), or that must be abandoned or replaced in accordance with 329 IAC 10-21-1(h), any monitoring well approved under 329 IAC 1.5, which was repealed in 1989, or 329 IAC 2, which was repealed in 1996, may continue to be used for ground water monitoring.(4) Replacement wells must meet the design requirements of 329 IAC 10-21-4, except for replacement wells under subdivision (5).(5) Replacement wells constructed within fifteen (15) feet of the original well may have soil sampling and soil sample testing requirements waived if: (A) the original well complies with 329 IAC 10-21-4; and(B) the waiver is approved by the commissioner.(j) Based on data collected from boreholes, piezometers, and ground water samples, the site-specific hydrogeologic investigation report must provide the following: (1) Sufficient data to specify the location for ground water monitoring wells.(2) Sufficient data to form the basis for contingency plans regarding ground water and surface water contamination.(3) Sufficient data to support the engineering design of the landfill.(4) Maps, cross sections, and other graphical representations.(5) An analysis of potential impacts on ground water quality, surface water quality, and water users in the event of a release from the MSWLF, including projected paths and rates of movement of both water-soluble and low-solubility components of leachate.(6) Sufficient information to characterize the site geology to allow for the evaluation of the proposed design's compliance with 329 IAC 10-16-9 and 329 IAC 10-17-2.(7) Detailed descriptions of the following: (B) Surface water and ground water flow.(C) The relationship of site-specific conditions to the regional geology.(D) The potential impact the proposed MSWLF unit or may have on surface and ground water resources and other receptors, including future hydrogeologic conditions, that may occur with site development.(E) Hydrogeologic conditions in sufficient detail to construct a comprehensive understanding of ground water flow.(F) The consolidated and unconsolidated stratigraphic units from the ground surface down through the materials comprising the confining unit defining the lower boundary of the uppermost aquifer system, including the following: (i) Sedimentary composition, including, for unconsolidated formations:(AA) textural classification;(BB) grain size distribution (sieve and hydrometer curves);(CC) hydraulic conductivity;(FF) transmissivity and storativity; and(GG) cation exchange capacity and Atterberg limits tests must be performed on a representative sample from each significant stratum encountered in each borehole in which a piezometer or monitoring well is to be installed. These tests may be waived for a sample if it is demonstrated that the sample is not conducive to these tests.(G) The geomorphology at the proposed MSWLF unit.(H) The structural geology under the proposed MSWLF unit.(I) The uppermost aquifer system and all significant zones of saturation above the uppermost aquifer system, including the following: (i) The depth to, and lateral and vertical extent of, the uppermost aquifer system and all significant zones of saturation above the uppermost aquifer system.(ii) Temporal fluctuations in ground water levels and the effects on ground water flow direction.(iii) An interpretation of the ground water flow system, described in both narrative and map form, that includes the following:(CC) Vertical and lateral components of flow.(DD) Interconnections between and within the uppermost aquifer system and any significant zones of saturation above the uppermost aquifer system.(EE) Ground water table maps or potentiometric surface maps, or both, of the proposed site, including ground water flow directions. Monthly water level measurements over a period of at least six (6) months must be submitted to the commissioner prior to operation of the proposed MSWLF or lateral expansion along with ground water table/potentiometric surface maps constructed from each measurement event.(FF) Cross-sectional representations of equipotential lines and ground water flow direction that adequately represent the horizontal and vertical flow directions beneath the site. Where appropriate, this information may be illustrated on the geologic cross sections.(iv) Identification and characterization of recharge and discharge areas within the boundaries of the proposed MSWLF unit, including any relationships of ground water with seeps, springs, streams, and other surface water features.
(v) Characterization of the vertical and horizontal hydraulic conductivity of the uppermost aquifer system and all strata within the zone of saturation above the uppermost aquifer system.(vi) Other information necessary to completely describe the uppermost aquifer system and all significant zones of saturation above the uppermost aquifer.Solid Waste Management Board; 329 IAC 10-15-4; filed Mar 14, 1996, 5:00 p.m.: 19 IR 1819; filed Mar 19, 1998, 11:07 a.m.: 21 IR 2761; filed Aug 2, 1999, 11:50 a.m.: 22 IR 3799; errata filed Dec 28, 2005, 12:46 p.m.: 29 IR 1561