Mercer County, NJ Environmental Rules: Erosion Control (2026)
Key Facts
- Permit required
- RCP/ROWOP for storm drain tie-ins
- Issuing authority
- Mercer County Engineer
- Review time
- Up to two weeks
- Hidden connections
- Prohibited outright
- Insurance minimum
- $1M bodily injury coverage
Summary
Any tie-in to a County drainage structure or storm drain system requires a Mercer County road construction/right-of-way occupancy permit before work starts.
A RCP/ROWOP shall be required for each approved connection into the County storm drain system, whether the connection is made with a new manhole or inlet, or is connected into an existing storm manhole or inlet. Connections that are not readily visible or are inaccessible are prohibited.
(3) A RCP/ROWOP will be required for each new or modified driveway or road intersection encroaching upon the County road or County right-of-way.
(4) Disputes concerning the need for a RCP/ROWOP shall be referred to the County Engineer.
C. Applicant's responsibilities.
(1) Any person or persons, firm, corporation, or municipality desiring to disturb, open, or make any type of excavation in any County road and/or County right-of-way shall have a completed RCP/ROWOP application and approved permit minimum of two weeks prior to the start of work, together with two sets of detailed plans indicating and describing in detail the work proposed to be performed and the estimated length of time required to perform same. This information shall be completed on forms provided by the Mercer County Highway Division.
(2) A RCP/ROWOP shall be required for connections into an existing County storm drain system. The County Engineer shall have up to two weeks to act upon applicants for RCP/ROWOP from their submission to receive approval. Thereafter, work can commence immediately after receiving an approved permit.
(3)
Full Breakdown
Mercer County doesn't zone or permit general site grading: that authority sits with its 21 municipalities. But any grading, driveway, or drainage work that ties into a County-maintained storm drain, manhole, inlet, or drainage structure needs a County Roadway Construction Permit (RCP) and Right-of-Way Occupancy Permit (ROWOP) from the County Engineer first. Connections into an existing storm drain system, whether through a new or existing manhole or inlet, trigger the requirement, and hidden or inaccessible connections are barred outright.
Violations & Fines
Excavating, opening, or tying into a County drainage structure or right-of-way without an approved RCP/ROWOP is unlawful; the County Engineer can reject nonconforming work and order removal and replacement.
Frequently Asked Questions
Does Mercer County issue general grading permits?
What if my driveway connects to a County storm drain?
Sources & Official References
Other rules in Mercer County
Compare Mercer County to another location·View the New Jersey environmental rules overview
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