Here is another thread that has easy to understand, very good advice for you and your pond building contractor about soil compaction for dug ponds and ponds with a dam and a core trench.
http://forums.pondboss.com/ubbthreads.php?ubb=showflat&Number=395066#Post395066 Choosing the best compaction device. esshup says: You can also pull a large sheepsfoot roller behind a dozer, but it won't be a vibratory one. The different lifts need to be KNITTED together with a sheepsfoot and not use a smooth barrel roller. You will end up with a pond bottom that looks like pages in a book when using a smooth barrel roller. Water can work it's way through each page, move horizontally until it finds another crack/fissure, go down a page, years of rinse and repeat until it leaks out of the pond. In a pond that has the lifts knitted together that won't happen - the water cannot move horizontally.
Compaction Discussion thread
http://forums.pondboss.com/ubbthreads.php?ubb=showflat&Number=409653#Post409653Here is some pretty good discussions how to determine if your soil is good enough to use for a pond.
http://forums.pondboss.com/ubbthreads.php?ubb=showflat&Number=421698#Post421698Fixing leakage around a drain pipe - options:
http://forums.pondboss.com/ubbthreads.php?ubb=showflat&Number=423269#Post423269Link about what makes clay/soil compact - seal.
http://forums.pondboss.com/ubbthreads.php?ubb=showflat&Number=454136#Post454136More information in a thread about compacting soil.
http://forums.pondboss.com/ubbthreads.php?ubb=showflat&Number=462372#Post462372QUESTION. "I’ve now had a second round of meetings with three contractors and am getting quotes. I asked each about compaction and use of a sheepsfoot roller. One of the contractors, who digs lots of ponds in the area, said he instead uses a loaded wheeled earthmover, and drives over everything so that the wheels have covered and compacted every square inch."
Commentary: Using a loaded earthmover can when used in proper soil /dirt conditions can compact good quality clay soil. Importance HERE is good quality clay. However very Important points are:
1. dampness of the clay material during construction; too dry of clay does not compact well.
2. thickness of the lifts that are placed on top of each other. Thicker the lifts less compaction there is between lift layers.
3. number of passes over each lift layer.
4. quality of the clay and dirt materials and amount of grainy sand veins can cause compaction problems IN BETWEEN and among the lift layers. Lift layer integrity is very important for sealing an entire pond basin and a dam that is very important for a watershed drainage pond.
These ALL four have to be in good condition for best clay compaction for building a minimal leakage pond.
When all the above items are optimum,,,, then clay compaction is adequate using a wheeled earthmover. Those four unknowns are too much of a gamble for leakage IMO. All have to be optimum for optimum results; less than optimum means leakage. When anyone of the above four are present,,, it or they can contribute to leakage pathways. Same goes for sheepsfoot rollers but leakage is less of a chance whenever the marginal conditions occur.
If it was my pond being built and the contractor was to use a Loaded Wheeled Earthmover, I would want a signed contract that if more than 12"-14" of water was below the overflow pipe during annual dry weather conditions, the contractor guarantees to return and find the leak and repair it no charge. The signed contract IMO emphasizes to the contractor to pay special close attention to clay compaction efforts. A neighbor's 0.3ac pond was built with a loaded wheeled earthmover. Pond receives house roof drainage. Clay was damp during construction, contractor was well experienced. Luckily clay was damp in spring and lift layers were spread thin when pond was built.
My contention is, if loaded wheeled earthmovers are adequate at clay compaction then why do specialized soil compacting sheepsfoot rollers and vibrating sheepsfoot rollers exist?
Remember the sheepsfoot roller KNITS, importance here is KNITS and interconnects the two clay lift layers together. Wheeled compactors just squeezes or presses the two clay layers together. Pressed together clay layers leaves a seam between the two layers and when soil/s are grainy or too dry, or too thick water can work its way more easily between the compressed layers. Subsoil has various soil type veins, textures and layers depending on how nature laid down the soil in Indiana during the periodic ice ages. Unknown subsoil layers can be a problem when building a dug pond.
