An issue relating to storm water infiltration in the municipal sewer system is being advanced by district councillor Herb Haldane.
The councillor had expressed concern on behalf of district taxpayers, wary that they may be required to foot the bill for work done to remediate feared “breaches” in the wastewater system which has been in service since 2004. EPCOR is the builder/operator of Sooke’s wastewater network. Dramatic spikes in volume handled by the system had occurred, most notably in the winter of ‘09.
Assorted data, including a piece of text from an EPCOR performance report, had raised Haldane’s suspicion of infrastructure woes and unwelcome bills to follow.
“During the heavy rain storm of December 2009,” the report states in part, “operators stayed at the plant round the clock to monitor the system and ensure the plant remained operational.”
A bit of background – the plant has an annual average daily flow of 3,000 cubic metres per day and peak wet weather flow of 6,900 cubic metres per day. It is stated in the EPCOR report that the plant is expandable by an additional 3,000 cubic metres per day (average daily flow).
Tami Wetmore, EPCOR Water Services Operations Manager for Port Hardy and Sooke regions, has subsequently fielded a series of related questions on the topic.
Wetmore said on February 18 that levels during this particular storm were the highest yet recorded. There were reported levels of “9,000 cubic metres per day at the highest, with brief peaks at nearly twice that rate.”
Wetmore indicated that the system was up to the task… handling the volume and keeping up to established standards. She mentioned the damaging windstorm of December 2006 as well, and declared, “In both situations the system performed extremely well.”
Councillor Haldane suspects sewer pipe is broken somewhere along the line and stormwater is rushing in “every time we get really heavy rain. So they have no choice but to pull the lever and let ‘er rip out into the ocean.” He says since a separate storm drain had not been installed the sewer takes on that role by default when enough rain falls.
“There is no storm drain underneath the sewer,” said Haldane. “We didn’t have enough money to do both.”
EPCOR-supplied data, as included on the District of Sooke’s website on the public information, FAQ section, states:
“Infiltration is a situation common to every sewer utility. Stormwater or groundwater makes its way into the system through inflow and infiltration (I & I) which can occur from a number of different sources including, among others, improper connections of homes or businesses to the system, cross connections with roof or foundation drains, open inspection chambers, and broken or leaky pipes. During severe storm events, such as the 2009 storm that caused significant flooding in Sooke, water will enter the system through the vent holes in manhole covers resulting in higher flows.”
Tami Wetmore asserts that there is no cause for alarm, that some sources of I & I have been identified and addressed at no charge to the district.
As for a relevant comment on the matter from district staff, Municipal Engineer Elizabeth Nelson stated on February 18 via email, “We have every confidence with EPCOR and their continued maintenance and response program for the sewer utility, and will continue to work closely with them.”