Overburden: There has been much recent discussion of material on the quarry property that has been called “overburden”. This material was orginally on top of the rock to be mined, hence the name. The practice was to remove and truck it to a pile before mining the rock below.
The pile grew over the years and the top was visible from Stonehouse Road and other locations. Some of us called it “Quarry Mountain”. In the drawings for rehab Plan 2003 it was shown as a pile of material near the south boundary of the property. The understanding during the review of Plan 2003 was that this material would be used for rehabilitation of the property when quarry operations ceased. It would be spread over the finished grade to support vegetation.
Rehab Plans and Drawings: The township quarry ordinance stipulates that the Quarry (MQI acting alone or jointly with Tilcon) submit a plan for rehabilitation of the quarry (rehab plan) every three years. Four plans were submitted since 2001. I name these plans for the year on the drawings submitted with the plans. These are Plan 2003, Plan 2006, Plan 2008, and Plan 2011.
A set of six drawings was submitted with each of the first three plans. Links for each of the Plan 2008 drawings are below. To view a drawing, first open a second window with this page. Then click on the drawing number. Size each of the windows and place then side-by-side (they may overlap) and use the cursor to move back and forth.
A drawing is in PDF format and window displays it with Adobe. Use the scroll and zoom controls to focus on a particular section.
The links to the Plan 2008 drawings are Dwg 1, Dwg 2, Dwg 3, Dwg 4, Dwg 5, Dwg 6.
Those not familiar with these drawings should start by opening Dwg 1. The drawing number and title “Cover Page” are in the lower right corner. Size the display so that the drawing fills the screen. This is the view from above the quarry and the surrounding properties and roads.
We can imagine that the quarry tract is shaped like the head of the cartoon character Road Runner. His beak points east (right) and touches Pond Hill Rd. The back of his head (left) is the west boundary with Stonehouse Rd. His head slopes down to the right along the railroad. Most interesting for purposes here is his chin just above the south boundary and the short new road High Hill Court (runs west from the north end of Overlook Ave). This is where the overburden was piled. Close this drawing by clicking the tab for the window.
Next open Dwg 2. This is also a view from above, but at a larger scale. The title in the lower right corner is “Reclamation Plan”. Size the image so that the entire drawing is visible and fills the screen.
There is a grid of horizontal lines (west to east) at intervals of 400 feet and vertical lines (north to south) at intervals of 200 feet. The origin is the upper left corner (northwest). The location of a point is determined by the horizontal distance moving right (east) from the origin and by the vertical distance moving down (south) from the origin.
The caption on a horizontal grid line is the number of feet going south. Example: “400” at the left end of the first grid line from the top. The vertical grid lines are called “Stations” and have unique captions. “2+00” at the top of the first grid line from the left means 200 feet going east.
The scale of a full-size drawing is 1 inch for 100 feet. The dimensions of one cell of the grid are 2 by 4 inches, representing an area of 200 by 400 feet. This is 80,000 square feet or 1.83 acres.
Road Runner’s chin area, where the overburden was piled, is bounded roughly by the vertical lines at 1600 and 3000 feet east and the horizontal lines at 2400 and 2800 feet south.
The curving lines are topographic contours. The heavy ones represent the proposed finished grade and the lighter dashed lines represent the “existing” grade (based on aerial photos taken on 10-31-07). The numbers in boxes next to the solid contour lines are the proposed elevations in feet msl (relative to mean sea level). The other numbers next to the dashed contour lines are the existing elevations.
Increase the magnification until you can see the individual contour lines and read the numbers. Find the grid intersection at 1800 feet east and 2800 feet south (above and left of the culdesac at the end of High Hill Court). Note the elevation 440 for an existing dashed contour line a little above (north of) this intersection. Note also the 340 foot solid projected contour line a little south of this intersection. We will return to these values in Dwg 4. Close Dwg 2 by clicking the tab for the window.
Analyzing the Overburden Pile, An Example: Next open Dwg 4. The title in the lower right corner is “Sections”. This shows cross sections looking east. North is to the left and south is to the right. The cross section at the bottom is at 1800 feet east. Focus on the right side of this cross section and adjust the magnification (to about 75%) so that you can read the numbers. The horizontal scale is feet south (read 28+00 as 2800) and the vertical scale is feet of elevation.
The drawing shows the profile of a sandwich with three layers. From top to bottom they are labeled “Extent of 2′ Cover Material”, “Material to be Mined”, and “Land Development Cut Material”. The line defining the top of the sandwich is the existing grade. The line at the bottom represents the proposed finished grade.
Recall the existing elevation of 440 feet a little west and north of the grid intersection at 1800 feet east and 2800 feet south in Dwg 2. The cross section drawing shows a 440 foot elevation at the top of the sandwich a little to the left (north) of the vertical line corresponding to 2800 feet south. Recall also that the solid countour for 340 feet elevation was just below (south) of this intersection. The cross section also shows this. These examples demonstrate the relationships between the contour lines in Dwg 2 and the cross section profile lines in Dwg 4.
Think of the three kinds of material at this location as veins running from west to east. Dwg 4 contains estimates of the cross section areas of these veins in square feet. They are from the top: Cover (7,846), to be Mined (17,746), and Cut (18,202).
Dwg 4 shows cross sections from 1800 to 3000 feet east. Dwg 3 is similar and shows sections from 0 to 1600 feet east, and Dwg 5 shows sections from 3200 to 4000 feet east.
Close Dwg 4 and open Dwg 5. In addition to the cross sections this drawing contains four tables of vein cross section areas and volume estimates derived from them. The first three tables are joined. From left to right they are for Material to Mined, Land Development Fill Material, and Land Development Cut Material. In the far left column are distances east expressed as sections. The row labeled “18+00” represents the cross section at 1800 feet east that we examined above. Note that the number from Dwg 4 for to be Mined (17,746) is entered in the corresponding row and column. Same for number for Cut (18,292).
The table for overburden is separate. The overburden number of 7,846 from Dwg 4 (labeled there as “Extent of 2′ cover material”) is entered in the row for 2000 feet east in the table. This should have been in the row for 1800 feet east and was a mistake. I believe these cross section estimates were generated by some kind of software and entered manually on the drawings and in the tables. The mistake here was simple human error.
SECTION ABOVE HAS BEEN ELABORATED AND REVISED.
WORK ON THIS POST WAS STOPPED IN JULY 2014. SECTION ABOVE IS RETAINED AS AID IN UNDERSTANDING CROSS SECTION DRAWINGS.
Bill Allen, 07-11-14 new. 07-19-14 revised.