Engineering Constraints¶
Engineering constraints are the site-feasibility checks that decide whether a BMP can keep its regulatory and technical promises once it is tied to real soils, groundwater, and contributory area. In the live source set, those checks are centered on BMP Manual Chapter 12 and Chapter 13 rather than on generic screening rules.
Structured citation evidence for this page lives in the sibling claim manifest.
Constraint Topics¶
| Constraint | Source-backed focus | Why it gates later work |
|---|---|---|
| Soil Permeability Testing | Chapter 12 test methods, design permeability, investigation depth, and testing density | Controls whether infiltration credit is technically supportable |
| Seasonal High Water Table | Chapter 12 SHWT determination and the static-SHWT separation framework | Controls available vertical separation |
| Groundwater Mounding | N.J.A.C. 7:8-5.2(h) plus Chapter 13 hydraulic-impact analysis |
Tests whether infiltration creates adverse subsurface impacts |
| Drainage Area Limits | BMP-specific chapter and NJAC table limits | Prevents the wrong BMP chapter from being stretched beyond its scale |
| Infiltration Feasibility | Combined Chapter 12, Chapter 13, and recharge-prohibition screen | Determines whether infiltration remains on the table at all |
How Constraints Filter BMP Selection¶
The source-backed workflow is sequential:
- Establish the site evidence chain with soil, SHWT, and drainage-area facts.
- Determine whether infiltration into subsoil is still viable.
- If infiltration remains viable, carry the tested inputs into recharge, mounding, and BMP sizing work.
- If infiltration does not remain viable, adjust the BMP shortlist before detailed sizing starts.
This is why the constraints module sits upstream of the main selection and sizing pages. The live citations layer does not support treating these checks as late-stage documentation clean-up.
Source Alignment¶
The current corpus supports a cleaner three-part framing than the older constraint summaries:
- Chapter 12 answers whether the site investigation is adequate and what design permeability / SHWT inputs can be used
- Chapter 13 answers whether proposed infiltration creates an adverse hydraulic impact
- the BMP chapters and NJAC tables answer whether the selected BMP is still within its own drainage-area and use limits
Together, those sources create the feasibility record that later pages in the BMP Library and Design Workflow rely on.