Sewage Archives - WJ Canada

Dewatering for Sump Installation

Dan Carpenter October 27, 2023

Dewatering for New Sump and Drainage Installations

If there is a requirement dewatering in a complex or challenging environment then WJ Canada are the ideal people to get in touch with, and this was the case on a recent residential development.

An existing residential tower development required the installation of an upgraded permanent drainage and sump system within the confines of the existing basement, in order to allow further development of the site. The client decided there was a need to install twin prefabricated sumps beneath the existing second level underground parking garage.

Unique Challenges

This provided a number of unique challenges – difficult access, restricted headroom, working in close proximity to structural pillars and footings of the existing building, as well as working in a very high yielding loose sand aquifer.

Successfully Dewatered

WJ successfully used one of our drilling set-ups, specifically modified to work on limited access and headroom sites, to install two perimeter vacuum wellpoint dewatering systems around the sump excavations. High yielding vacuum wellpoint pumps were used in tandem to dewater each of the excavations to their target drawdown levels, allowing easy and seamless excavation, placing of the new sump, and backfilling by the installation contractor. There were strict requirements in place to ensure that the groundwater pump was free of sediment to mitigate the risk of ground settlement (which was a significant concern at the site), so this was monitored by a third party throughout the installation and running of the system, fortunately the works were carried out successfully.

How WJ can help you

WJ offer solutions for all types of geology and can meet the challenge of working within limited spaces that have sensitive requirements.

WJ wellpoint installation at UOIT September 2019

Stormwater Bypass near Jumeirah

WJ Group Admin September 24, 2019

Over pumping from manhole for constructing additional downstream manhole

Dubai Municiaplity continue to invest and build on their existing utility network in Dubai. As part of upgrades, WJ Middle East undertook the storm water by pass works from manhole to manhole at Jumeirah using our high capacity diesel centrifugal pumps. We installed our heavy-duty temporary HDPE discharge bypass lines up to 100m in length. We had anticipated large volume of flows through the main network as it was near the outfall point. WJ successfully diverted the flows with no impact to the main network.

Stormwater Bypass, Nakheel Metro Station

WJ Group Admin September 24, 2019

Over pumping for the upgrade of existing Metro Station

Description: The Nakheel Harbour and Tower (NHT) Station upgrade is a part of the Dubai Metro expansion works and it is located on Ibn Battuta Street. The Red Line Metro extension to Expo 2020 site shall intersect at NHT Station. WJ Groundwater Limited undertook the storm water & sewage over pumping works using our high capacity diesel centrifugal pumps. We installed our heavy-duty temporary HDPE discharge bypass lines up to 250m in length. The over pumping system was operated and monitored by WJ personnel continuously throughout the project. A flowmeter was used to monitor the system flow rate. WJ Groundwater has also successfully executed and installed our advanced deep line plugging system to divert flows.

The Garden Sewage Treatment Works

WJ Group Admin September 24, 2019

WJ undertook sewage over pumping works as part of maintenance works at The Gardens Sewage Treatment Works in Dubai.

WJ were contracted by Hydrojet to divert incoming mains sewage from the works inlet to the neighbouring aeration tanks whilst they carried out maintenance works at the pumping station for Nakheel.

WJ installed a high performance overpumping system using two of its high capacity 400 l/s diesel suction pumps and HDPE suction and discharge lines that took sewage from the inlet chamber and distributed flows evenly between 4 no. aeration tanks. The pumps used were brand new, ultra-efficient BBA BA300k sewage pumps. They are specifically designed to handle sewage with a semi-open impeller design capable of handling solids up to 100mm. A key selling point to Hydrojet was that the pumps used nearly half the fuel consumption of those offered by other dewatering contractors which helped to reduce their costs. Due to the sensitive nature of pumping sewage we provided 100% spare pumping capacity to ensure continuous operation, along with electromagnetic flow meters and full time supervision to monitor system performance.

The project was a great success and WJ was impressed by the professionalism of Hydrojet and look forward to working with them again on future projects.

Sewage Bypass at Dubai Downtown

WJ Group Admin September 24, 2019

Over pumping for existing Network Upgrade

We have installed, commissioned and operated a temporary over pumping system at Down Town Dubai to facilitate construction of service tunnels and roads in the area. The existing sewer network was diverted through our temporary setup. The pumping station had a peak flow of 1500 m3/hr.