|
|
|
|
|
|
|
15
Conference Conclusions |
|
|
|
|
|
|
|
|
The closing roundtable discussion session of the Conference showed that there was strong consensus on two matters: |
|
|
|
|
|
|
|
|
low-cost sewer systems are an important technology which is cost-effective in many situations; and |
|
|
|
|
|
|
|
|
there is an urgent need to disseminate this message effectively. |
|
|
|
|
|
|
|
|
However, the details of follow-up action remained, probably inevitably, somewhat contentious. Perhaps the debate can be simplified by dividing it into two parts: |
|
|
|
|
|
|
|
|
What are we trying to disseminate? |
|
|
|
|
|
|
|
|
While this is an over-simplification (different lessons will need to be disseminated by different channels), it does at least provide a framework for decision. |
|
|
|
|
|
|
|
|
The first step is therefore deciding what we know about the topic. There are clearly two conflicting approaches here. One is highly scientific and involves resolving professional differences of opinion over, for example, hydraulic design. The other is pragmatic, and says, in effect 'we know that sewers can be as small as 50 mm diameter and can be laid with grades as flat as 1 in 2000. Whether in theory these values could be slightly bigger or smaller does not matter. We cannot construct sewers more accurately than 1 in 500 anyway, and the saving in cost between 50 mm pipe, which we feel uneasy about, and 100 mm pipe, which we are comfortable with, is not significant. Adopting minimum values of, for example 1 in 500 and 100 mm as interim |
|
|
|
|
|