Using pivot table to count values in multiple columns

Hi - I have a little project that I am working on and I thought could use pivot table. I need to check 3 different columns to see if the value is true, and if it is, then find out how many times this occurs. These are test results of 3 types of bacteria which were tested on various surfaces. I want to see the date, surface that each bacterium meets the condition (or values are true). I would also like to filter it many ways like by year, month, etc..Is there a way that I can make a pivot table and display the number of times the values are true.

Please see the attached spreadsheet (Excel 2007) with sample data. On the sample pivot tab, I have displayed how I would like to see the pivot table. I appreciate any help. Thanks in advance.