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→Key Components, Test Methods and Equipment
Key components of LID BMPs that should be the subject of sediment accumulation testing (i.e., depth measurements) are described in the table below along with recommended test methods. Depth measurements should be recorded on inspection field data forms provided on each associated [[Inspection and maintenance#Practice-specific Inspection and Maintenance|BMP's I&M page on the wiki]], used to determine if sediment removal maintenance is needed.
Key components of LID BMPs that should be the subject of sediment accumulation testing (i.e., depth measurements) are described in the table below along with recommended test methods. Depth measurements should be recorded on inspection field data forms provided on each associated [[Inspection and maintenance#Practice-specific Inspection and Maintenance|BMP's I&M page on the wiki]], used to determine if sediment removal maintenance is needed.
{| class="wikitable" style="width: 900px;"
|+'''Key components and test methods for sediment accumulation testing by BMP type'''
|-
!<br>'''LID BMP Type'''
!<br>'''Key Components'''
!<br>'''Recommended Test Method'''
|-
|rowspan="3|'''[[Bioretention]] / [[Bioswales]] / [[Dry swale]] / [[Enhanced grass swales]] / [[Vegetated filter strips]]'''
|-
|[[Inlets]]; [[Pretreatment|Pretreatment devices]]
|Use a tape measure or probe to measure the depth from the bottom elevation of the pretreatment device or surface of the filter bed (adjacent to the inlet structure), below any stone or mulch cover present, to the highest elevation of accumulated sediment present. For catchbasins, manholes and hydrodynamic separator pretreatment devices a sludge sampler (e.g., “sludge judge” sampler) should be used to sample the sediment and estimate depth accumulated in sumps. Record the measurement and remove the sediment if it exceeds trigger values for follow-up action.
|-
|[[Filter media|Filter Bed]]
|Use a tape measure or probe to measure sediment depth from the surface of the filter bed, below any stone or mulch cover present, to the elevation of accumulated sediment present in at least five (5) locations evenly distributed over the filter bed surface area. Record the measurements, calculate the mean sediment depth and compare to trigger values to determine if follow-up/corrective actions are needed.
|-
|rowspan="3"|'''Underground infiltration systems ([[Soakaways]], [[infiltration trenches]], [[infiltration chambers]] and [[Exfiltration trench|perforated pipe storm sewer systems]]'''
|-
|[[Inlets]]; [[Pretreatment|Pretreatment devices]]
|Use tape measure or probe to measure the depth from the bottom elevation of the inlet pipe or pretreatment device, below any stone or mulch cover present, to the highest elevation of accumulated sediment present. For catchbasins, manholes and hydrodynamic separator pretreatment devices a sludge sampler (e.g., “sludge judge” sampler) should be
used to sample the sediment and estimate depth accumulated in sumps. A measuring tape or staff gauge installed in the structure and set to the bottom elevation can provide another means of tracking sediment accumulation. Record the measurement and remove the sediment if it exceeds trigger values.
|-
|[[Filter media|Filter Bed]]
|(Applicable to vault-type infiltration chamber systems only) - Use a tape measure or probe to measure sediment depth from the surface of the gravel bed to the elevation of
accumulated sediment in at least five (5) locations evenly distributed over the bed surface area. Record the measurements, calculate the mean sediment depth and compare to trigger values to determine if follow-up/corrective actions are needed.
|-
|rowspan="2"|'''Cisterns ([[Rainwater Harvesting]] & [[Rain barrels]])'''
|-
|[[Rainwater harvesting: Sizing and modeling|Cistern]]
|From outside the cistern use a tape measure or probe to measure the depth from a fixed point (e.g., rim of the access hatch) to the bottom elevation of the cistern and to the
highest elevation of accumulated sediment present. Subtract the two values to calculate the sediment depth. A sludge sampler (e.g., “sludge judge” sampler) may also be used to
sample the sediment and estimate depth. A staff gauge installed on the cistern wall and set to the bottom elevation provides another means of measuring sediment depth that does not require entry into the confined space. Record the measurement and remove the sediment if it exceeds trigger values for follow-up action.
|-
|}
==Surface Infiltration Rate Testing==
==Surface Infiltration Rate Testing==