Blackburn Wastewater Treatment Plant Upgrade Study

As noted previously, comparisons of recorded flows to theoretical generated flows
indicates that inflowlinfiluation appears to k the result of snowmelt or rainfall events.
and does not occur yqr round. This comparison also indicates that, except for
snowrne1tlr;linfall evenu. then is relatively little year-round infiltration to the Blackburn
system.
This is important in understanding and mitigating inflowfinfiitration as both
identification of problem arcy and monitoring the results of upgradiing works is
effactiveiy limited to king done during thest events. Si rainfall events occur with on
an irregular basis. the mos effective time ta identify problems and to manitor rtsSs of
uppdiig wiil continue to be during the spring snow-melt period. A comparison of the
1997, 1998 and 1999 snow melt events indicates that sp~g
snow-melt and it's effect on
the Blackbum sewer system can also vary widely so care will need to be taken in
interpreting the results of upgrading activities.
5.2 SUMMARY OF RECOMMENDATIONS FOR
UPGRADING
The recommendations of this study include:
a) upgrading manholes. including repairs to manhole stmcnucs, cappinglxaling of
unused connections and Suds and d i g and waterproofing mahhole~ subject to
being overtopped by srorm wm. See Section 4.1 and 4.3 for derails.
a) upgrading piping, as determined by the 1991 television camera work (if not already
done)
b) thorough cleanins of kouf sscdons of the sanitary sewer system prior to tdevision
came~ins@o& to determine if inflow from broken pi& is occurring, and repair
of any infiltratins piping. See Section 4.4 for details.
C) monitoring of specific areas of the system prior to and during spriag mow melt in
order to limit inflow from avoidable dirch~creck backup. See Section 4.2 for details.
d) plumbing insptcrions to determine if basement sump pumps are insnlled and
connected to the smiwry system.
e) smoke testingto identify mof dr;lim or parking area drains c onnd to the sanirvy
system.