Lake Sampling Locations (click on site for more information):

List of Location Descriptions 
 

Monitoring

• Monitoring is performed monthly during the summer (May through September).
• Lakes have 1-12 stations depending on the size and the characteristics.
• Database includes chemical and physical results dating back to 1981

Ambient Lakes Monitoring Program Lakes are greater than 10 acres and meet one or more of the following criteria:

• Accessible to the public
• A drinking water supply
• Significant recreational use
• As requested, depending on its characteristics or water quality concerns

Methods

A detailed Quality Assurance Project Plan (QAPP), which includes specific methodology, was approved by the EPA in 2014. Physical data such as temperature, dissolved oxygen, pH and specific conductivity are collected from the surface to bottom. Chemical data are collected in the photic zone (zone of light penetration). Common chemical parameters include total residue, total suspended residue, turbidity, chlorophyll a, phytoplankton and nutrients.  Hardness is collected at the surface.

NC Trophic State Index

North Carolina Trophic State Index (NCTSI) is calculated by using chemical and physical parameters to determine the productivity of a lake. The NCTSI formula for this calculation is as follows:

• NCTSI = TONScore+ TPScore+ SDScore+ CHLScore
• CHL = Chlorophyll a (μg/l)
• TON = Total Organic Nitrogen (mg/l)
• TP = Total Phosphorus (mg/l)
• SD = Secchi Depth (inches)

NCTSI- North Carolina Trophic State Index Scale:

Reports

Basinwide Assessment Reports are created every 5 years on a rotating basis. Reports for a given summer season are typically uploaded the following spring. All reports are uploaded here. 

Staff Contacts

Return to Intensive Survey Branch