More complications for Bus Rapid Transit.

CTV News has unearthed new details about city hall's proposal to build a BRT tunnel beneath Richmond Row.

A geotechnical report confirms sandy soils and underground water would complicate construction.

This borehole is one of three drilled near the proposed BRT tunnel back in November.

The report confirms sandy soil conditions, and groundwater at a depth that could cause problems for construction.

Options include using a "cut and cover" or "top down" tunnelling method, and designs that would collect and drain water away from the tunnel, without requiring sump pumps.

It also recommends more research be done about the possible impacts "de-watering" will have on soil settlement and nearby properties.

 The 900 metre tunnel would allow rapid transit buses to pass beneath the railroad tracks that cross Richmond Row.