Who should I contact to test soil for new construction ?

You need to hire an engineer who specializes in soil compaction, load bearing and hydro geology. Construction on sandy soil (unconsolidated soil is the technical term) is possible but it requires special techniques. Techniques to limit the subsidence that can happen during periods of heavy rainfall, natural underground water flows and earthquakes. Concrete footings in sandy soil usually have to be deeper and wider and stabilized with crushed stone. The gradients around the site have to drain rainwater away from the house to limit under washing of the foundation, etc. I'm sure someone on DR1 has encountered theses problems. They can refer you to an engineer or consultant with the proper expertise.

In North America, good site analysis can involve trench excavation and/or coring, and water drainage tests. Usually takes a day or two to complete. No idea what the standards are in the DR or the cost. It is important to have an analysis done before you start construction. I've seen many town homes and villas here with major structural cracking due to improper building techniques.

Epsa Labco, Dr Franco Gomez 809 221 3772; franco.gomez@epsalabco.com

Professional, knowledgeable and highly recommenced but not cheap. Initial quotation for a site survey is usually free of charge. I had this firm out to my property on the north coast and am quite satisfied with their competence and thoroughness.