Further investigation of why the south/east side of the pool deck dropped slightly revealed that the General Contractor that made the other mistakes also incorrectly packed the soil in that area. Instead of removing the wet clay and then pouring a base material for 4-6" and then lifts of soil every 6" that is compacted and vibrated, they threw an inch of soil of sand over existing soil.
This means that whole area could shift as non-impacted sand for 1" becomes a slide vs a base. We are working against time with El Nino coming as this area would not have survived a heavy rain season. As such heavy equipment will be brought in today to quickly remove the interlocking pavers in that area. It is a trade off between cost and time. Each paver is approximately $3.00, using a bulldozer will damage a large percentage of the pavers. On the other side, if El Nino arrives soon, we won't have this finished and that creates a lot of complications.
At this point, we have already hauled away 126 tons of damaged soil from the pipe burst and we will likely have tens of tons more to remove and replace. The crew continues to open damaged areas, dig out the damaged soil, lay base, sand and impact so the least amount of area is exposed. One complicating factor is the original drains installed when Wolf Creek was built was not hooked up to the surface drain and as such, water just dropped into the ground over the last 8 years and the soil absorbed the moisture thus damaging our prior concrete deck.
We had the last soil test performed last Monday and it looked good coming out of the ground. The soil was tested to 31.5 feet below surface in the area that appeared to have a large cavern. I will let everyone know when the results come in. As of know, we are approximately $150k into this repair. The repair is under the supervision of a contractor that is charging us a consultant fee and we are subbing in all of the sub-contractors. This keeps our costs at actual cost vs the contractor mark up. If we allowed the contractor to arrange all of this we would be closer to $400k in cost. Every effort is being made to wrap this project up, but we will not take any short cuts that only passes this problem on to future boards.