January 9, 2003

Memo to EPA

I accompanied Mike McCann and Neil Vaughn on January 7 to perform additional field reconnaissance of the area southeast of Neal Landfill. The purpose of this reconnaissance was to identify additional karst features that could be used for tracer injection as part of Viacom's Northwest Spring System basin delineation investigation. The areas examined where the Edwards property, immediately north of the intersection of Cave Road and S.R. 48, and the Richard Hamilton properties located west of Cave Road and south of S.R. 48. Mr. Hamilton owns a couple of hundred acres in the area, and has granted Viacom permission to walk the property and conduct tracer tests.

I arrived at the site at about 10:00 as Mike and Neil were finishing up a reconnaissance of the Edwards property. They examined two sinkholes on the property. One sinkhole was located on a hillside on the property which was regarded by McCann as a potential tracer location. I did not look at this sinkhole. Mike had also been told about, and found, an old well at a farmstead on the Hamilton property on the south side of S.R. 48. The well is also regarded as a potential tracer location point.

We began an examination of the Hamilton properties about 10:30. The property is densely vegetated, and in places difficult to traverse. With the aid of a detailed air photo and topographic map of the area (Figure 1) it was possible to determine the locations of several potential tracer injection points. The property contains a large north-south oriented karst valley. Drainage from clastic-capped ridges to the east and west flows into the karst valley and sinks into many well defined sinkholes and swallowholes. There is virtually no surface drainage that leaves the area south of S.R. 48, west of Cave Road, and north of Holland Hill Road. All surface drainage enters sinkholes and swallowholes located within the karst valley and its tributary drainageways.

We did not attempt to inventory all karst features in this area. As most of this area is remote from roadways, a good tracer injection strategy would be to use natural storm runoff into sinkholes and swallowholes to inject the dyes. So, the reconnaissance work concentrated on features evident on the contour map that were associated with drainageways entering the karst valley, or the karst valley proper.

Potential dye injection points were located and photographed (see attached photos). A hand held GPS receiver was utilized to determine the approximate UTM NAD 83 position of each feature. as a check on the location identified from the topographic map. Approximate coordinates are provided in Table 1. Features are described in the following.

Feature 6 - This feature is two small sinkholes, 30 feet in diameter and 8 feet deep located along the axis of a minor drainageway entering the karst valley from the east. The sinkholes each have a small drainage channel entering from the upslope side. These are located downstream from the previously located Feature 2. The photograph is a view of the westernmost feature, viewed looking west.

Feature 7 - Feature 7 is approximately 30 feet in diameter and 10 feet deep and is located in a minor drainageway entering the karst valley from the west. It is located between two other features (Features 8 and 9) that pirate the entire flow from the drainageway. No picture was taken.

Feature 8 - This features serves as a terminal swallowhole for the drainageway entering it from the west. An open crevice in bedrock was noted. The photograph is a view of the feature looking west showing the bedrock crevice.

Feature 9 - This sinkhole is the largest, and upstream most, of the three sinkholes in the drainageway. The sinkhole contains two separate swallet areas. The photograph shows the downstream swallet in the foreground and the upstream swallet in the background. This is an excellent tracer injection point due to the presence of a large drainage area.

Feature 10 - This feature is one of two principal swallet areas in a large western tributary to the karst valley. The swallet has a surface channel about four feet wide feeding into it, and does not appear to overflow. This is an excellent tracer injection point. The two photographs, one a southwest view and the other a northeast show the drainageway leading into the swallet area.

Feature 11 - This is a large sinkhole of the ridge slope that contains an active soil slump. This sinkhole is most accessible from a property on the south side of S.R. 48. Features 10 and 12 are probably better injection points to use in this area.

Feature 12 - This is a large channel swallet, and possible cave, located near where the western karst valley tributary enters the main valley area. The photograph shows the potential cave entrance (dark void) with the swallet in the upper right hand portion of the fram. The cave entrance drops about drops 6 feet into bedrock. A crawl leads from the bottom of the hole. This is an excellent tracer injection point.

Mike told me that he had received a call from the Sarbers on S.R. 48. They do not object to tracer testing on their property, and according to Mike, did mention the presence of a pit and cave beneath a trash pile in the valley behind their home.

Mike mentioned that they may do initial background sampling of springs in the area next week in anticipation of tracer injection during upcoming storm events.