§ Mr. Eldon Griffiths
Since wide variations can and do occur between conditions in one stretch and another of a river, the 1970 river pollution survey classified each stretch of these rivers—as distinct from the river as a whole—according to its condition.
The survey of January 1972 shows that since 1970, 45 miles of river in the area of the Yorkshire River Authority have improved in quality and 20 miles have deteriorated. These changes have occurred over short, non-tidal stretches on 33 rivers.
A further report updating the survey to January 1973 is expected to be published early next year.