ADS StormTech DC-780, Design Manual

Call StormTech at 

860.529.8188

 or 

888.892.2694

 or visit our website at 

www.stormtech.com

 for technical and product information.

32

12.0 Inspection & Maintenance

12.3 ECCENTRIC PIPE HEADER INSPECTION

Theses guidelines do not supercede a pipe 

manufacturer’s recommended I&M procedures. Consult 

with the manufacturer of the pipe header system for 

specific I&M procedures. Inspection of the header system 
should be carried out quarterly. On sites which generate 
higher levels of sediment more frequent inspections may 
be necessary. Headers may be accessed through risers, 

access ports or manholes. Measurement of sediment 

may be taken with a stadia rod or similar device. Cleanout 

of sediment should occur when the sediment volume 

has reduced the storage area by 25% or the depth of 
sediment has reached approximately 25% of the diameter 

of the structure.

12.4 ECCENTRIC PIPE MANIFOLD MAINTENANCE

Cleanout of accumulated material should be 
accomplished by vacuum pumping the material from the 
header. Cleanout should be accomplished during dry 
weather. Care should be taken to avoid flushing sediments 
out through the outlet pipes and into the chamber rows.

Eccentric Header Step-by-Step Maintenance 
Procedures

1.  Locate manholes connected to the manifold system

2. 

Remove grates or covers

3. 

Using a stadia rod, measure the depth of sediment

4. 

If sediment is at a depth of about 25% pipe volume or 
25% pipe diameter proceed to step 5. If not proceed 

to step 6.

5.  Vacuum pump the sediment. Do not flush sediment 

out inlet pipes.

6.  Replace grates and covers

7.  Record depth and date and schedule next inspection

STORMTECH ISOLATOR™ ROW - STEP-BY-STEP
MAINTENANCE PROCEDURES

Step 1)

 Inspect Isolator Row for sediment

A) Inspection ports (if present)

  i.   Remove lid from floor box frame

  ii.   Remove cap from inspection riser

  iii.  Using a flashlight and stadia rod, measure

    depth of sediment

  iv. If sediment is at, or above, 3” (76 mm) depth

    proceed to Step 2. If not proceed to Step 3.

B) All Isolator Rows

  i.   Remove cover from manhole at upstream 

    end of Isolator Row

  ii.  Using a flashlight, inspect down Isolator

    Row through outlet pipe

    1. Follow OSHA regulations for confined 

      space entry if entering manhole

    2. Mirrors on poles or cameras may be used

      to avoid a confined space entry

  iii.  If sediment is at or above the lower row of

    sidewall holes [approximately 3” (76 mm)]

    proceed to Step 2. If not proceed to Step 3.

Step 2)

 Clean out Isolator Row using the JetVac process

A) A fixed floor cleaning nozzle with rear facing

  nozzle spread of 45” (1143 mm) or more is 

  preferable

B) Apply multiple passes of JetVac until  

  backflush water is clean

C) Vacuum manhole sump as required during 

  jetting

Step 3)

 Replace all caps, lids and covers

Step 4) 

Inspect and clean catch basins and manholes 

upstream of the StormTech system following local  

 guidelines.

Figure 20 – StormTech Isolator Row (not to scale)

Figure 21 – Eccentric Manifold Maintenance

4

2

1) B)

1) A)

1, 2, 6

3, 4, 5

Please contact StormTech’s Technical Services 
Department at 888-892-2894 for a spreadsheet to 

estimate cleaning intervals.