Re the Good Beach Guide:
The very wet spells we had last summer did trigger a number of sewer system emergency overflows. These functioned as designed, preventing the sewer system backing up into people's homes. Emergency overflows are regulated by the environment agency (SEPA) and generally discharge dilute, screened waste water, not raw sewage.
As for the treatment works at Nairn, it treats sewage to produce a high quality effluent - a clear water which is dispersed way out in the Moray Firth and nowhere near the beaches. And I can assure your reader interested in the impact of extra housing that this will not reduce the quality of the finished clear water.
One of your correspondents makes the very apt point that during bad weather all sorts of 'diffuse pollution' (run off from the countryside) enters the river and is washed out to sea. If you look at the samples taken by SEPA off Nairn last summer (posted on their website and at the noticeboards by the harbour and the links) you'll see they were all 'excellent' or 'good'.
It might be of interest to your readers that Scottish Water recently gave evidence to the Scottish Parliament's flooding bill, suggesting that the best way to improve the sewer system's ability to cope with the sudden downpours we're seeing more of is to remove surface water connections from the system. We encourage developers to install rainwater recycling systems and would like to see more green roofs and car parks with porous surfaces.
I hope this information is useful to Gurnites. Keep up the good work with your superb blog.
Scottish Water & Nairn Resident!