Monitoring wells: Installation

Monitoring well stack installed next to underdrain within the LID practice. (Photo Source: CVC, 2010)

Monitoring wells allow for measurement of water levels in the sub-surface components of LID practices. They are important for sampling procedures and ensuring that the LID feature are performing as intended.

Construction Steps:

1. Install a cap stand at the required elevation to anchor the monitoring well.
2. Wrap the perforated pipe with a geotextile sock (to prevent migration of soil into the well).
3. Anchor the perforated pipe to the bottom of the LID feature.
4. Install a lockable cap to the top of the standpipe to protect against vandalism.
5. Install monitoring equipment (e.g., a level logger) if required.

Key Inspection Points:

• Pipe is perforated, rigid, and matches design specifications.
• Well is installed according to contract documents.
• Geotextile sock is wrapped around the perforated portion of the well.

Mistakes to Avoid:

• Incorrect sequencing – ensure that standpipe is installed prior to backfilling with granular material.

A perforated pipe used to assist the draining of soils.

Low Impact Development. A stormwater management strategy that seeks to mitigate the impacts of increased urban runoff and stormwater pollution by managing it as close to its source as possible. It comprises a set of site design approaches and small scale stormwater management practices that promote the use of natural systems for infiltration and evapotranspiration, and rainwater harvesting.

Credit Valley Conservation

Filter fabric that is installed to separate dissimilar soils and provide runoff filtration and contaminant removal benefits while maintaining a suitable rate of flow; may be used to prevent fine-textured soil from entering a coarse granular bed, or to prevent coarse granular from being compressed into underlying finer-textured soils.

Filter fabric that is installed to separate dissimilar soils and provide runoff filtration and contaminant removal benefits while maintaining a suitable rate of flow; may be used to prevent fine-textured soil from entering a coarse granular bed, or to prevent coarse granular from being compressed into underlying finer-textured soils.

Gravel, or crushed stone of various size gradations (i.e., diameter), used in construction; void forming material used as bedding and runoff storage reservoirs and underdrains in stormwater infiltration practices.