Last year we added an addition onto our house located in Nova Scotia on the Bay of Fundy.The foundation is ICF and the header spaces are insulated with spray foam. There is drainage tile around the outside of the foundation. The problem - I'm getting around 4gal of water a day from my dehumidifier in the crawl space! (unheated). The floor of the crawl space is earth/sand/PLASTIC/Sand. There is no standing water and no signs of leakage but the top layer of sand is wet in some areas. There is no ventilation in the crawl space. Any ideas on how I can remedy this? I can provide additional info if required