While water contamination is still a problem that can result from shale oil and gas drilling, fewer cases of pollution have been reported so far in 2014, according to WTAE-TV Pittsburgh.

Both conventional and unconventional drilling practices have been known to contaminate water supplies. Only a handful of water contamination cases have been confirmed this year, compared with 43 cases that were reported in 2010.

However, officials are unsure of the total number of contamination cases because of how records were kept. Also, in the early years of the shale boom, pre-drilling water testing wasn’t common, so it is possible that some reports of contamination were pre-existing and not caused by drillers.

Via: WTAE-TV Pittsburgh > 5 things to know about gas boom and polluted water