State the limitation early
If the property has no usable water hookup, tell the provider during the initial logistics discussion. Identify any restrictions on existing water sources without offering them as approved supply. Ask what the specific product and application method require and which resources the contractor proposes to provide.
Avoid improvising a solution
Do not arrange mixing, transfer or substitute supply based on a general internet description. The applicator needs to follow the instructions for the actual product and use. Keep any unresolved resource question visible before approving a schedule, especially on remote or seasonally occupied land.
Tie the answer to the proposal
For WTG, request confirmation of the access and resource assumptions behind the quoted work. If property conditions change, report them before the visit. The final agreement should leave neither party expecting the other to provide something unspecified. A preliminary inquiry does not mean every site without a hookup can be served.