In 2006, the VLMP was re-organized to address the ever-increasing need for reliable data to support environmental decision-making and regulations. To meet this need, a new structure base for the VLMP was developed, called the Tiered Approach. This structure was developed to take into account the needs of both the Illinois EPA and the volunteers by establishing different levels of volunteer participation and data use. The Tiered Approach allows volunteers the freedom to choose their level of participation in the program that suits their needs while still providing Illinois EPA with reliable data to make lake assessments, which are required by Section 305(b) of the Federal Clean Water Act.
In this tier, volunteers perform Secchi disk transparency monitoring and record field observations. Monitoring is conducted twice per month from May through October typically at 3 in-lake sites.
In addition to monitoring Secchi disk transparency, Tier 2 volunteers enter the advanced water quality program by collecting water samples for nutrient, suspended solids, and chlorophyll analyses at Site 1. Water quality and chlorophyll samples are taken once per month in May – August in conjunction with one Secchi transparency monitoring trip.
This is the most intensive tier. In addition to monitoring Secchi disk transprency, Tier 3 volunteers are also part of the advanced water quality program and collect water and chlorophyll samples at up to 3 sites on their lake. As in Tier 2, their samples are analyzed for nutrients, suspended solids, and chlorophyll. This tier may also include Dissolved Oxygen/Temperature profiles as equipment is available. As in Tier 2, water quality and chlorophyll samples are taken once per month in May – August and October in conjunction with one Secchi transparency monitoring trip.
Data collected in either Tier 1 or Tier 2 are used primarily for educational purposes.They are used to make general water quality assessments and help the volunteer to determine trends or to identify potential problems in their lake or watershed to assist them in making better lake management decisions. Data collected in Tier 3 are used to make use-support decisions, which drives the Agency's impaired waters list.