Refer to the JCW Grease Management: Grease Waste Plumbing, Interceptor Design and JCW Inspections page for JCW design standards and inspection requirements.
1. Hydromechanical grease interceptor (HGI) manufacturers must electronically submit information for each model\unit to Johnson County Wastewater (JCW) for review, coordination and acceptance of the HGI unit’s installation detail before the model may be permitted and installed in JCW’s service area. JCW will coordinate with the manufacturer to develop the JCW HGI Unit Installation Detail for each HGI unit accepted for use.
2. Only HGI units with a HGI Unit Installation Detail accepted by JCW may be permitted and used in JCW’s service area.
3. Only projects with a JCW accepted HGI Unit Installation Detail will be accepted for permit review.
4. Elements required for development of the JCW HGI Installation Detail for each unit include (and may not be limited to):
a. Each model\unit shall be certified to ASME A112-14-3-2018 Type C or D 100 gpm. Identify the Type (C or D) and provide all certification test data indicating grease capacity and efficiency in accordance with Section 3.4.6 including incremental test data to breakdown in accordance with Section 220.127.116.11.
b. Units requiring external flow control may not be used. Units without integral flow control are preferred. Where integral flow control devices are required for the unit, the integral flow control devices shall be serviceable from finish grade and instructions for accessing the integral flow control device shall be included on the detail.
c. Designs shall be for single stand-alone unit with a minimum 2500 lb grease capacity on a 90-day cleaning frequency. Interceptors in series or parallel may not be used.
d. Watertight pickable cast iron covers meeting AASHTO M306 H20 Traffic Rating are required. Composite lids may not be used.
e. Each unit shall be designed for an exterior buried installation.
f. A H20 load bearing protective concrete slab is required for all units. The design for the H20 slab sealed by a Kansas PE must be included on the JCW HGI Unit Installation Detail.
g. Under JCW standards, infiltration testing of the installed interceptor, risers and castings is required. The test method shall be included on the JCW HGI Unit Installation Detail. Contact JCW with any questions regarding the method.
h. Include a two-way tee cleanout immediately upstream of the unit and a vented sampling port on the outlet of each unit on the detail. Refer to JCW’s standard two-way cleanout\sampling port detail.
i. Clearly note minimum and maximum burial depths on the JCW HGI Unit Installation Detail.
j. Provide core sample measurement limits for the “full” grease and “full” solids in each unit on the JCW HGI Unit Installation Detail.
k. JCW inspection is required at several steps during the installation of the interceptor and grease waste system. Manufacturer’s representatives are urged to include this JCW inspection awareness in discussions with the installer to avoid rework. Required inspections such as the following examples will be included in JCW’s Permit:
1. Interior Grease Plumbing Inspection. In addition to the City interior plumbing inspection, JCW inspection of the grease waste plumbing and fixtures inside the building is required prior to pouring the interior floor slab.
2. Grease Interceptor Installation Inspections
a. Partial Inspection #1: JCW inspection of the excavation, interceptor, riser(s) and anchor kit (if applicable) is required prior to backfill.
b. Partial Inspection #2: Haunched pipe, backfill, cleanout and sampling port shall be inspected prior to pipe backfill.
3. Grease Interceptor and Risers Vacuum\Leak Test Inspection. JCW must witness the interceptor and risers test noted on the JCW HGI Unit Installation Detail.
4. Grease Interceptor H20 Concrete Slab Rebar Inspection. JCW inspection of the rebar configuration is required prior to the slab pour.
5. H20 Concrete Slab Installation Inspection. JCW inspection of the completed concrete slab including placement of castings within the slab is required at the completion of the concrete pour.
JCW Hydromechanical Interceptor Manufacturer Criteria for Unit Acceptance 11-2-20 (Pending JCW ESC final review)