Levy County Douglas M
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DONALD HOLMES, DIST. NO. 1 THE BOARD OF COUNTY SAMMY YEARTY, DIST. NO. 3 BRONSON, FLORIDA CHAIRMAN COMMISSIONERS GULF HAMMOCK, FLORIDA J. L. TOWNSEND, DIST. NO. 2 CHIEFLAND, FLORIDA LEVY COUNTY DOUGLAS M. McKOY P. O. DRAWER 310 CLERK TO THE BOARD MIKE DAVIS, DIST. NO. 4 BRONSON, FLORIDA 32621 CEDAR KEY, FLORIDA GREG BEAUCHAMP m ATTORNEY FOR BOARD ELMER SMITH, DIST. NO. 5 WILLISTON, FLORIDA f PHONE (904) 486-4311 Extension 32 WILLISTON General This site was opened as a Class II sanitary landfill in 1976. Waste was last received in 1984 and fianl cover was placed prior to December 30, 1984. According to Levy County personnel, only household garbage and con struction rubble were buried on this site. The County "controls" this site by virtue of a land lease between themselves and Ms. Micki Borowski. Currently, the site is used as a pasture and cattle are grazing here. The site is located approximately 2 miles east of the Town of Williston. The surrounding property to the north nad east is being used as pasture for cattle. Residential development occurs within 1500 feet to the south of the closed landfill. There are also some single family homes lying approximately 500 feet west of the site. The surrounding property is zoned R-3 and is classified as prime agricultural land by the Levy County Comprehensive Plan prepared in 1978. Regional Geology & Hydrogeology The Geology of the area of the landfill site typically consists of limestome lying fairly close to the surface with a layer of clayey sands of varying thickness overlying it. The clayey sands which crop out in Gilchrist, western Alachua, and Levy counties belong to the Alachua Formation. The Alachua is of upper Miocene, possibly Pliocene age, and clayey sands, and sandy clays. The Alachua has been mined in many localities in the map area for the hard rock phosphate that is commonly found in its lower section. The top of the Florida Aquifer occurs at an elevation of approximately 70 feet N.G.V.D. in this vicinity (per 1979 map prepared by D.N.R. in conjunction with S.R.W.M.D. entitled "TOP OF THE FLORIDAN AQUIFER OF NORTH CENTRAL FLORIDA") However, a map prepared by SWFWMD depicting the Potentlometric surface of this aquifer shows the potentlonetrlc surface in this area to be at an elevation of approximately 53 feet N.G.V.D.. This probably indicates a high potential for recharge to the Floridan Aquifer in this area. Site Specific Geology & Hydrogeology The completion reports for the existing wells reveal the diverse litho logy of the Alachua formation on this site. Llmerock was excavated during the digging of the cells at this site. Water was encountered at a depth of approximately 4~0~~feet, which is in agreement with the SWFWMD potentlometric surface map. Most probably, no confining layer exists between the bottom of the cells and the top of the Floridan Aquifer. However, there seems to be approximately 25 feet between the bottom of the cells and the high water surface in the aquifer. Willlston Landfill Page 2 Physical Characteristics The cells within the landfill are all approximately 10' to 12' deep. Refuse was compacted with a bulldozler equipped with a landfill blade. Cover was applied at regular intervals. A minimum of 2 feet of native sand was applied as final cover. The disturbed areas have been graded and seeded with bahis grass. This grass has sprouted well enough to graze cattle on. How ever, there are some signs of minor erosion in areas where the grass has not come in. Recommendations Four monitoring wells shall be Installed at the locations indicated on the attached survey. These wells should all be drilled to a deptbof 50 feet which will place the screened interval below the potontiometric surface of the Floridan Aquifer. These wells shall be constructed according to the details as shown in attached Exhibits A & B. Samples will be collected from each well on a quarterly basis. Static water levels in each will be measured prior to purging the well. These levels will be measured by inserting a steel tape on the casing and measuring the distance from the top of the well casing to the free water surface. After taking this measurement and prior to sampling, the well will be purged and a minimum of four (4) well volumes evacuated from the casing. A hand-actuated pump constructed of PVC and equipped with a double foot-valve will be used to purge the wells and to collect water quality samples. Water quality samples will be collected by an employee of Mills Engineering Company or by an employee of Levy County under the supervision of Mills Engineering Company personnel. This same person will also measure the static water level in each well. Ste rilizing sample containers will be obtained from the laboratory which will perform the tests on the day prior to collecting the samples. The samples will be returned to the laboratory immediately after they are collected. The transportation and presevation of these samples will be in accordance with the laboratory's Instructions. The analytical methodology and detection limits that the laboratory must adhere to are attached as Exhibit C. The parameters to be monitored Include: primary and secondary drinking water standards, total organic carbon, volatile organic carbon, and specific conductivity. The site should also be re-seeded with bahia grass and fertilized. Peri meter ditches should also be dug to intercept runoff. Upon acceptance of this plan by D.E.R., the wells will be installed and testing will begin. Monitoring will continue for 20 years or until D.E.R. recommends it cease. ^=__ F_ ^<^yfATyF^^ aea^r /f/ea<y4/^ a. {?/a ry/y/^^z ^rzmze^/zmA/ ^MOKJ i TO 12 (MG WELL Will i3T OKI LAKDFILL LEVS' COU KIT Y EKKi&iT A‘ Specifications for Monitoring Well Installation All monitoring wells shall be installed by a Certified Water Well Contractor. The monitoring wells shall be installed by the Hollow Stem Auger Method. Prior to installation of each monitoring well all auger equipment shall be decontam inated by steam cleaning and rinsed with clean clear water. Bentonite drilling fluid may be used during the drilling of the monitoring well. The monitoring wells shall be a minimum of two (2) inch diameter. All well casing shall be constructed of PVC (Schedule 40) with threaded joints. No solvent weld joints will be accepted. The well screen shall be PVC with 0.010 inch slot size of the length shown on the drawings or as determined during installation by the Engineer. A tail pipe two (2) feet in length shall be connected at the bottom of the well screen to accumulate sediment. The bottom of the tail pipe shall be sealed. The monitoring well casing, screen, tail pipe, and caps shall be decontaminated by steam cleaning and rinsed with clean clear water prior to assembly and installation. The monitoring well casing shall be installed straight, plumb, and centered in the drilled six (6) inch borehole. The use of centralizers may be required to assure that the well is properly centered with the minimum annular space being not less than one and one-haIf (1^) inches. The monitoring well casing shall extend two (2) feet above ground surface. The top of the monitoring well shall be pro tected with a threaded PVC removable cap having a maximum one-eighth (1/8) inch vent hole drilled in the top. A locking protective steel casing and concrete pad shall be installed around the monitoring well. The protective steel casing shall have a minimum diameter of four (4) inches, be five (5) feet in length, and extend above the top of the monitoring well cap two (2) inches. The mini mum dimensions of the concrete pad poured around the pro tective steel casing, at ground surface, shall be two (2) feet by two (2) feet by four (4) inches. The top of the monitoring well and the protective steel casing shall be neatly cut at a right angle to the casing. EKHi&lT ' B' i 2- The annular space between the drilled hole and the monitoring well casing or screen shall have a minimum dimension of at least one and one-half (l^g) inches. This space shall be gravel packed with clean-washed gravel from the bottom to a depth of approximately two (2) feet above the top of the well screen. Fine clean-washed sand shall be used as a seal above the gravel pack material for a depth of approximately two (2) feet. Cement grout shall be placed by the tremie pipe method from the top of the fine sand seal to the concrete pad at ground level. The monitoring well shall be developed by the air injection method to produce clean-clear sand free water. The well shall not be developed or pumped for a period of at least twenty- four (24) hours following installation. The monitoring well identification number shall be clearly visible at the outside of each protective steel casing. An elevation reference point, marked by a V-notch cut into the monitoring well casing and the protective steel casing shall be provided. Also, a metal survey marker shall be set in the concrete pad as an addition elevation reference point. All elevation reference point elevations shall be establised, based on National Geodetic Vertical Datum (N.G.V.D.). The location of all monitoring wells (active and abandoned) shall be horizontally located by the Cartesian Coordinate System, the center of all wells shall be surveyed and the locations drafted on a grid overlay base map.