Sounds like your top table could be compiled with something like this:
proc sql;
create table polCounts as
select
County,
Site,
Pollutant,
sum(matrix="Soil") as nbSoil,
sum(matrix="Groundwater") as nbWater
from myData
group by County, Site, Pollutant;
quit;
where myTable would be your input data table with columns County, Site, Pollutant, and Matrix ("Soil" or "Groundwater")
replace sum(matrix="Soil") as nbSoil with sum(matrix="Soil") > 0 as nbSoil if you only want zeros and ones.
... View more