Frequently Asked Questions (FAQ)

What is an interbasin transfer?
When is EMC certification required?
What is the cork rule?
What is required for EMC certification?

Q. What is an interbasin transfer?

A.  An interbasin transfer is the movement of surface water from one river basin into another.  The actual transfer is the amount of water not returned to its source basin.

The most typical situation occurs when a water system has an intake and wastewater discharge in different basins, but other situations also cause transfers.  One is where a system's service area covers more than one basin.  Any water used up or consumed in a portion of the service area outside of the source basin would be considered part of a transfer (e.g. watering your yard).  Transfers can also occur between interconnected systems, where a system in one basin purchases water from a system in another basin.

At some level, interbasin transfers can begin to have detrimental effects on the downstream environment and downstream users.  The Regulation of Surface Water Transfers Act ensures that large transfers with this potential are subject to thorough technical and environmental review.  The Act defines 38 separate river basins.

Q. When is EMC certification required?

A.  Certification is required connected with:

• New transfers of 2 MGD or more require certification
• Increases in existing transfers of 25% or more above average daily amount transferred during the year ending July 1, 1993, if the total transfer including the increase is 2.0 MGD or more.
• The Surface Water Transfer law includes a grandfather provision for existing facilities and their capacity to transfer water on or prior to July 1, 1993.

Q. What is the cork rule?

A.  North Carolina general statute 15A NCAC 02E .0401(b) states: "Pursuant to G.S. 143-215.22G(3)(a) and 143-215.22G(3)(b), and notwithstanding the definition of basin in G.S. 143-215.22G(1), the following are not transfers:  (1) The discharge point is situated upstream of the withdrawal point such that the water discharged will naturally flow past the withdrawal point.  (2) The discharge point is situated downstream of the withdrawal point such that water flowing past the withdrawal point will naturally flow past the discharge point.

This is nicknamed the "cork rule" because if a cork were dropped into a waterbody at a system's discharge point and the cork could eventually float past the system's withdrawal point (or vice versa), then the water discharged would meet the rule criteria and is not an interbasin transfer (even if the discharge and withdrawal points are in different basins).

The following scenario meets the cork rule:

The above scenario meets the cork rule because a cork dropped at the withdrawal point would eventually pass the discharge point.

The following scenario does NOT meet the cork rule:

The above scenario does not meet the cork rule because a cork dropped at either point would not physically pass the other.

Q. What is required for EMC certification?

A. The procedure for obtaining an Interbasin Transfer Certificate is specifically laid out in G.S. §143-215.22L.  The full process can take three to five years and offers a number of opportunities for public comment and review.  Division staff has developed a guidance document to assist entities that wish to pursue a certificate.