I picked it up in the Bedrock Strait neighbourhood in Oasis Springs. Basically you can pick it up in any neighbourhood that has one somewhere in the vicinity, but to first place it on a lot you will always need the T.O.O.L. mod that allows you to pick up stuff outside of your lot borders. That's why I saved the lot with it on the gallery. That way it is possible for people to use it who don't want to (or can't) install mods themselves and it is easier to transfer it to neighbourhoods that don't have one. It's just a bit tedious as you need to place the pump as the very first thing and build the rest around it.