A few days ago I contacted the local water board about Surface Water
Discharge fees (my place has soakaways) and today received the following
standard letter:

"We are satisfied that none of the surface water from your property
drains into a public sewer and you therefore qualify for a rebate from 1
April 2008. Unfortunately I am unable to send you a revised bill for
the period 1 April 2008 to 15 August 2008 as metered charges has been
raised from 16 August 2008. Therefore, I have credited your account
with an amount of £8.26 in respect of the surface water drainage charges
for the above mentioned period. You will receive the amended bills
within the next seven days. You do not have to apply again next year
and the charge will not be included in your future bills. Wastewater
standing charges for waste (foul) water and highway drainage only will
be shown.

"If you are paying your water services charges by instalments, there
will not be an immediate change to the amount you pay. We will make the
adjustment when your next payment scheme is calculated.

"It has been necessary to cancel the invoices dated 17 February 2009 to
8 August 2013 in order to apply the rebate. I have issued a new invoice
dated 7 February 2014. The new invoice covers the period up to 29
January 2014 but includes the total of your payments made up to 7
February 2014 so it shows a credit balance of £118.21. I have arranged
for a refund of £118.21 to be credited back to the bank account from
which we collect Direct Debit payments. This will appear in your
account within the next five working days. "


If anyone hasn't heard of the problem with SWD charges just do a little
googling; from my experience it seems like an easy win. Now, what drill
shall I buy myself with the rebate? ;-)