Can a utility company add a donation to a non-profit to your utility bill without your permission.
I have seen bills that mention a "donations to charity" done two ways:
optional: for example a voluntary donation to a fuel fund that helps poor people avoid getting their heat turned off in the winter. Or a program to support organ donations. This last one was an optional one i saw a few days ago when I re-registered my car via the DMV website.
Notification: They specified that they donated x$ to a charity for every customer that did Y. So if you signup for online billing they will donate $2 to a fund to save trees.
Of these two the first example is one I see by far the most. It is simple and optional. The second one is rarely seen, becasue some customers will complain. They want the savings to go back to them.
The one you are asking about, which is neither of the two above: a mandatory additional donation I have never seen. The biggest problem with a utility company doing a mandatory charity program, at least in the United Sates, is that what they charge your for their services is regulated. In order for their to be one electric company, or one water company or one cable company they have to be a quasi-goverment organization. The local/state government and the utility negotiate the rates. They can charge a$ a month for administration, b$ per 1000 gallons for water delivery and c$ per 1000 gallons for sewage treatment. These negotiated rates leave no room for the utility to increase everybody next bill by $10 just so there can be a mandatory donation to a charity.