62-701.410. Hydrogeological and Geotechnical Investigation Requirements

(1) Applicability. Except as otherwise specifically provided herein, disposal facilities remain subject to the provisions of Rule 62-701.410, F.A.C., that were in effect at the time the facility was permitted or received a site certification, or at the time a complete application was submitted and deemed complete by the Department. This rule shall apply to permits or site certifications issued after February 15, 2015 for new disposal facilities or lateral expansion of existing disposal facilities that were not authorized by the Department in a permit or site certification prior to February 15, 2015. It is not the intent of this rule to require the owner or operator of any disposal unit for which a hydrogeological and geotechnical investigation has been approved in a permit by the Department to submit a new or updated report unless unstable areas have been discovered at the disposal facility since approval of the original investigations, or if design or operational changes will make the original investigations obsolete or incomplete.

(2) Hydrogeological investigation and site report. The hydrogeological investigation and site report required by subsection 62-701.330(3), F.A.C., shall be site specific, shall be conducted by or under the supervision of a professional geologist or professional engineer with experience in hydrogeologic investigations, and shall:

(a) Define the geology and hydrology of the disposal facility site and its relationship to the local and regional hydrogeologic patterns including:

1. Direction and rate of ground water and surface water flow, including seasonal variations;

2. Background quality of ground water and surface water;

3. Any on-site hydraulic connections between aquifers;

4. For all confining layers, semi-confining layers, and all aquifers below the site that may be affected by the disposal facility, the porosity or effective porosity, horizontal and vertical permeabilities, and the depth to and lithology of the layers and aquifers; and

5. Topography, soil types and characteristics, and surface water drainage systems of the site and surrounding the site.

(b) Include an inventory of all the public and private water wells within a one-mile radius of the site. The inventory shall include, where available:

1. The approximate elevation of the top of the well casing and the depth of each well;

2. The name of the owner, the age and usage of each well, and the estimated daily pumpage; and

3. The stratigraphic unit screened, well construction technique, and static water levels of each well.

(c) Identify and locate any existing contaminated areas on the site.

(d) Include a map showing the locations of all potable wells within 500 feet of the waste storage and disposal areas to demonstrate compliance with paragraph 62-701.300(2)(b), F.A.C.

(3) Geotechnical site investigation. The geotechnical site investigation required by subsection 62-701.330(3), F.A.C., shall be conducted by or under the supervision of a professional engineer with experience in geotechnical engineering. Investigations required in paragraphs (a) through (d) of this subsection may be conducted by a professional geologist. Prior to any construction on the site, the engineer shall define the engineering properties of the site that are necessary for the design, construction, and support of the disposal facility and all installations of the facility and shall:

(a) Explore and describe subsurface conditions including soil stratigraphy and ground water table conditions;

(b) Explore and address the presence of muck, previously filled areas, soft ground, and lineaments;

(c) Evaluate and address fault areas, and seismic impact zones, as described in 40 C.F.R. 258.13, hereby adopted and incorporated by reference (http://www.flrules.org/Gateway/reference.asp?No=Ref-05041), and 258.14, hereby adopted and incorporated by reference (http://www.flrules.org/Gateway/reference.asp?No=Ref-05041). To obtain these documents see subsections 62-701.210(6) and 62-701.210(7), F.A.C., respectively;

(d) Include estimates of the average and maximum high ground water table across the site;

(e) Include a foundation analysis to determine the ability of the foundation to support the expected maximum loads and stresses imposed by the disposal facility. It may include geotechnical measures necessary to modify the foundation to accommodate the imposed loads and stresses. The foundation shall be analyzed for short-term, end of construction, and long-term stability and settlement conditions. Considering the existing or proposed subgrade conditions and the disposal facility geometry, the analysis shall include but not be limited to:

1. Foundation bearing capacity;

2. Subgrade settlements, both total and differential;

3. Subgrade slope stability;

(f) Evaluate the potential for sinkholes and sinkhole activity as those terms are defined in Section 627.706(2), F.S., and unstable areas as described in 40 C.F.R. 258.15, hereby adopted and incorporated by reference (http://www.flrules.org/Gateway/reference.asp?No=Ref-05041). To obtain this document see subsection 62-701.210(8), F.A.C. The initial site investigation phase shall include, at a minimum, an evaluation of the following for the proposed site:

1. Historical aerial photography;

2. Site topographic survey to indicate potential depressional areas;

3. Lineament features that transverse the site;

4. General information indicating the potential for sinkhole formation such as the Floridan Aquifer Vulnerability Assessment (FAVA) map at http://www.dep.state.fl.us/geology/programs/hydrogeology/FAVA, and sinkhole or subsidence occurrence maps; and,

5. Results of borings and/or geophysical work performed to describe the nature of the subsurface geology and hydrogeology for the proposed landfill site, including the potential for unstable areas as described in 40 C.F.R. 258.15; and,

(g) If the investigations required above indicate that portions of subsurface below the disposal facility show signs of past sinkhole activity, or are reasonably expected to develop sinkholes or sinkhole activity in the future, additional geotechnical investigations shall be included to further characterize the subsurface below the disposal facility for the purpose of assessing potentially unstable areas and for evaluating the effectiveness and design for any engineering measures proposed for any potentially unstable areas. The investigation shall also include an evaluation of any engineering measures needed to provide reasonable assurance that the subsurface of the site in those areas will be adequate to support the disposal facility without adversely affecting the performance of the liner or leachate collection system.

(4) Geotechnical report. The geotechnical site investigation report shall describe the site subsurface conditions and shall include, at a minimum, the methods used in the investigation, including but not limited to, all soil boring logs and laboratory results, analytical calculations, cross sections, interpretations and conclusions. The report shall also include a description of any engineering measures proposed for the site.

(5) Report verification. The site reports and supporting information, including detailed description of the methods, calculations, and interpretations used, shall be signed and sealed by the appropriate professional. The hydrogeological report shall be signed and sealed by a professional geologist or professional engineer with experience in hydrogeological investigations. The geotechnical report shall be signed and sealed by a professional engineer with experience in geotechnical engineering. Any portion of the geotechnical report conducted or prepared by a professional geologist shall be signed and sealed by the professional geologist who performed the work.

Rulemaking Authority 403.061, 403.704 FS. Law Implemented 403.0877, 403.702, 403.704, 403.707 FS. History–New 1-6-93, Formerly 17-701.410, Amended 12-23-96, 5-27-01, 1-6-10, 2-15-15.