448 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. 



of collection was about 20 feet. A sample of water was 

 taken from the same place at the same time. Another 

 sample was taken from the channel close up to the rocks 

 at Penhelyg Point, at a distance of about half a mile 

 from the sewer outfall. The depth of water here was 

 about 18 feet, and the mussels were raked from the 

 bottom of the channel. A water sample was also taken 

 from this place. 



The conditions at Aberdovey are not such as suggest 

 contamination, on a superficial view of the estuary. The 

 latter is rather over a mile in width at Aberdovey, so 

 that an enormous volume of water must flow in and out 

 at every tide. This water coming directly in from 

 Cardigan Bay must be very clean. But if the estuary 

 be examined at low water the conditions will then be 

 seen to be such as must lead to most serious pollution of 

 the mussel beds. 



The population of Aberdovey varies from one to two 

 thousand persons. The sewage produced is intercepted 

 and discharged by a single sewer, a 15-inch iron pipe, 

 discharging near to the Pier, and the end of which is 

 covered by about 3 feet of water at low water of spring 

 tides. There is no treatment of the sewage, but the 

 outflow is intermittent. It lasts for about half an hour 

 at about half-flood tide, and for the remainder of twelve 

 hours the sewage is banked up in the pipe by a penstock. 

 The object of this arrangement is to prevent the fouling 

 of the bathing place, which is situated to the west of the 

 pier. The cU rec tion of flow of the sewage is said to be 

 such that it is carried over towards the south side of the 

 estuary and then out to sea. If the arrangement for 

 liberating the sewage is strictly adhered to, and if the 

 direction of flow is that stated above, it is difficult to 

 see how the mussels in the estuary can be fouled. Still, 



