Retrospective Evaluation of Cured-in-Place Pipe - (NEPIS)(EPA ...
Retrospective Evaluation of Cured-in-Place Pipe - (NEPIS)(EPA ...
Retrospective Evaluation of Cured-in-Place Pipe - (NEPIS)(EPA ...
Create successful ePaper yourself
Turn your PDF publications into a flip-book with our unique Google optimized e-Paper software.
comb<strong>in</strong><strong>in</strong>g this broadly available <strong>in</strong>formation with additional detailed evaluations <strong>of</strong> selected l<strong>in</strong>ers. It<br />
should be noted <strong>in</strong> this regard that select<strong>in</strong>g l<strong>in</strong>ers with more severe exposure conditions or other<br />
circumstances likely to cause an accelerated deterioration may provide a greater understand<strong>in</strong>g about<br />
deterioration mechanisms, but may not be representative <strong>of</strong> the deterioration <strong>of</strong> l<strong>in</strong>ers <strong>in</strong> general use.<br />
To get the best value from retrospective evaluation activities, it is recommended that a dual track be<br />
followed <strong>in</strong> which aggregated experiential and condition assessment <strong>in</strong>formation on l<strong>in</strong>ed pipes be<br />
collected from cities that are will<strong>in</strong>g to participate together with cont<strong>in</strong>ued <strong>in</strong>tensive evaluation <strong>of</strong> l<strong>in</strong>ers<br />
that have seen a variety <strong>of</strong> service conditions.<br />
Municipalities have shown great <strong>in</strong>terest <strong>in</strong> hav<strong>in</strong>g better nationwide <strong>in</strong>formation on the experience with<br />
the rehabilitation technologies that they are us<strong>in</strong>g or consider<strong>in</strong>g. It also appears from the discussions<br />
with municipalities regard<strong>in</strong>g the pilot studies described here that municipalities would be will<strong>in</strong>g to<br />
participate <strong>in</strong> provid<strong>in</strong>g data about their own experiences <strong>in</strong> return for be<strong>in</strong>g able to access the nationally<br />
aggregated <strong>in</strong>formation. Some municipalities may have limited resources to assist <strong>in</strong> the dig up and<br />
retrieval <strong>of</strong> host pipe samples or even l<strong>in</strong>er coupons (from larger diameter pipes). As mentioned earlier,<br />
be<strong>in</strong>g able to comb<strong>in</strong>e the sample retrieval with other needed work – either on the sewer, on neighbor<strong>in</strong>g<br />
utilities, or on the pavement above the sewer – significantly eases the decision <strong>of</strong> the municipality to<br />
participate.<br />
7.4 Aggregat<strong>in</strong>g National Data on L<strong>in</strong>er Performance<br />
S<strong>in</strong>ce the ultimate goal <strong>of</strong> carry<strong>in</strong>g out retrospective evaluations is to be able to provide better guidance to<br />
municipalities on the long-term performance <strong>of</strong> the various rehabilitation technologies available to them,<br />
it is worth look<strong>in</strong>g ahead as to how that data might be collected <strong>in</strong>to a national database.<br />
Table 7-3 provides a summary <strong>of</strong> an overall structure that could be used for such a database. The agency<br />
or municipality will be the key provider <strong>of</strong> the <strong>in</strong>formation and the agency name, contact <strong>in</strong>formation for<br />
the person provid<strong>in</strong>g the data, system size, and current extent <strong>of</strong> rehabilitation should be recorded.<br />
Various agencies would have differences <strong>in</strong> the types <strong>of</strong> technologies used and the specifics <strong>of</strong> those<br />
technology applications. It is suggested that the categorization <strong>of</strong> the city experiences be able to be as<br />
detailed as the city data would allow, but would also allow <strong>in</strong>formation capture at a broader level when<br />
only that level <strong>of</strong> <strong>in</strong>formation was available. For example, Agency A may be able to break down their<br />
experiences with CIPP <strong>in</strong>stallations by whether they were hot-water or steam-cured, which type <strong>of</strong> res<strong>in</strong><br />
was used, etc. Agency B may only have reta<strong>in</strong>ed sufficient records to be able to provide <strong>in</strong>formation on<br />
the length <strong>of</strong> l<strong>in</strong>es rehabilitated with CIPP and their general experiences with CIPP. The database should<br />
be able to focus on or exclude specific variants if desired or to analyze all <strong>of</strong> the CIPP data <strong>in</strong> aggregate.<br />
As discussed <strong>in</strong> Section 7.3, broad <strong>in</strong>terpreted data from agency records, CCTV <strong>in</strong>spections, and<br />
condition assessment databases needs to be able to be accessed <strong>in</strong> the database <strong>in</strong> addition to well<br />
characterized, quantitative data from retrospective l<strong>in</strong>er test<strong>in</strong>g or the use <strong>of</strong> specific NDT approaches to<br />
l<strong>in</strong>er evaluation.<br />
It is not <strong>in</strong>tended that the database proposed would attempt to <strong>in</strong>clude all <strong>of</strong> the <strong>in</strong>dividual CCTV or<br />
condition assessment data that cities are collect<strong>in</strong>g. Rather, the database proposed would conta<strong>in</strong> the<br />
<strong>in</strong>terpreted results from agencies <strong>of</strong> the performance <strong>of</strong> rehabilitation technologies plus specific physical<br />
or NDT that addresses l<strong>in</strong>er performance or degradation. The aggregation <strong>of</strong> all <strong>in</strong>spection and condition<br />
assessment <strong>in</strong>formation would provide additional opportunities for understand<strong>in</strong>g l<strong>in</strong>er performance, but<br />
is an effort that would require a larger level <strong>of</strong> resources to accomplish.<br />
105