reporter: when you turn on the tap and grab a glass of water tonight, you might want to thank tom grizzard>> that's the reason why you have this nice clean water that you want to keep drinking. >> tom grissard, virginia tech civil engineer. he ran what's known as the watershed monitoring lab. in the 1970s when water quality was in jeopardy. he and his lab on the front line of making sure water in the lake reservoir was safe. but he was also a pioneer in ensuring that treated water from prince william county was also clean when it went downstream. >> he was just very brilliant individual. that's all i can industry turned to for answers was tragically killed last week in a cycling accident at this busy intersection. >> tom hired me in 1984. >> barbara worked with him at the lab for decades. >> tom grizzard is known as the protector of the watershed. i really don't know who is going to fill those shoes. >> he's a manassas director of utility. >> right now hard to believe that he's no longer there. and i won't be able to pick up the phone and call him when i'm stuck. >> he's retired from the l

last week he died in a bicycling accident. >> tom grizzard is known by many as the and i really don't know who is going to fill those shoes. >> it's a sad event. and, so, there will be people that miss him greatly. >> even though they retired from the lab a few years ago. he now -- he has served on the utility commission and was duly consulting work with clients from as far away as singapore. >> with the track program now wrapped up. riders are hoping for more reliable safer. >> but not all disstaasters are preventable. perhaps the most serious in 2015 with smoke filled with tunnel and hot plaza and a woman died, even before trains roll into louden county, first responders there are gearing up for potential trouble on the tracks. our northern virginia bureau reporter shows us how. of us will likely pass on jumping out of a window head first. it's another day of training for the louden county fire and rescue crews. but their curriculum much like the region they'll serve, rapidly expanding. >> everything from flash over simulators, liquid propane gas fires, everything like the french re