not going to start a pissing match here, but have you seen how dirt is attracted to diesel fuel exposed to the elements vs gasoline? gas evaporates very quickly, diesel kind of hangs around for a long time, I highly recommend a cap over the filling port at all times while not in use
X2 $2.50 2' vent cap form Home depot works great, just a little trimming and fits nice.
I posted this at 1500.com so I will post it here.
Most Insurance companies require daily reports inspections on under ground Tanks, that means privately owned station must comply, Now Corp Station may be self insured. MNBlue Does all most all the Tank cleaning scrubbing In MN Parts of WI / IA call them and they will tell you who has the cleanest tanks.
MN
1 Superamerica
2 KwikTrip
3 Holiday
But I did get contaminate fuel form Holiday June of 2013 , and it was a corp Station , I was PO for years, It was a empty transfer (100 Gallon) tank that Was just Cleaned BY ME at Bioclean Systems, I have close ties to this company for 34 Years, We know how to clean Tanks, it was check By ME, Scott , Blaine. it was bone dry and perfectly clean, When filling the transfer tank I started the Auxiliary tanks Pump which is equip wit Zinga AE-3AZL filter ,The Best Aqua-Zorb filter I know, The Transfer pump shut down almost immediately (Filter plugged 100% shut), I then checked the tank WOW I stopped the retail Pump at Holiday and found the Station Manager to check it out it had 62 Gallons pump in, She said She would call corp office ,GO FOT IT I'm not moving and call the police, Blaine Police arrived and verified the contamination , Corp send MNBlue to stick the Tank I waited until MNBlue arrived, it was ***** and I know this person and we torpedo sample the tank It had some sentiments but that was it , What happen was Tanker just left minutes before I showed up and dropped 9500 Gallons of clear #2 this stirred the Tank and I suck up a pocket of water. Holiday Did nothing. MNBlue Pumped My auxiliary tank Dry, I Changed the Zinga filter which after inspection the element was laden with water, I filled at SA stirred the tank with the auxiliary Pump changed the Zinga filter again and all was good, Here's a picture of the fuel Pod the sample was taken form