The easy way is http://www.freeflood.net which is fairly accurate, but if you need to be doubly sure, then you'd want to go to http://www.fema.gov for a flood map or geta flood certification from a title company.
Pompton Lakes has many houses for sale that require flood insurance. Fema.gov is a website you can try to use, but it is difficult to navigate. The best way is to call the listing agent or another Realtor who is familiar with the area. In most cases, we would know just by the address. Good luck!