There is a contingency in almost all pool contracts, pertaining to unusual soil conditions. This could mean loamy or sandy soil, which collapses as it is dug, requiring reinforcing, garbage soil, which is soil which most dumps will not accept without a surcharge, or hard soil, such as difficult caliche, granite, huge boulders, requiring additional time and/or equipment to complete the excavation. When we have some of these conditions, “overbreak” may be necessary; this means, additional shotcrete to assist in the reinforcement in loamy soil or fill in voids resulting from rocky conditions. There is an additional cost to dig the pool when these items arise. They are most common in mountains or hill sides but can occur elsewhere. We will not know the cost until excavators look at the attempted excavation and provide a bid. We will normally secure three bids on your behalf to get the best possible price. Overbreak costs are not known until the shotcrete application is completed.