Amendments to the 2001 Murderkill
River TMDL Proposed

 The Delaware Department of Natural Resources and Environmental Control (DNREC) is planning to hold a public workshop on August 12, 2004 to present proposed amendments to the 2001 Total Maximum Daily Load (TMDL) for the Murderkill River.

The 2001 Murderkill River TMDL requires that point and nonpoint sources of nutrients (nitrogen and phosphorous) as well as oxygen consuming compounds be reduced significantly in order to meet the State of Delaware’s water quality standard and nutrient targets.  (The biological oxygen demand (BOD) of the oxygen consuming compounds reduces the amount of dissolved oxygen available to aquatic life forms.)   The standard for dissolved oxygen is 5.5 mg/l for fresh water segments of the river and 5.0 mg/l for marine waters.  These are considered daily averages for the period of June through September.  Nutrient targets are 3.0 mg/l for total nitrogen (TN) and 0.2 mg/l for total phosphorous (TP). 

After the 2001 TMDL regulation was adopted, the Kent County Levy Court, which owns and operates the Kent County Wastewater Treatment Facility, appealed the regulation to Delaware’s Environmental Appeals Board and to the Delaware Superior Court.  In its appeal, the levy court expressed concerns that the model that DNREC used underestimates the area and tidal velocity of the Lower Murderkill River, thus underestimating its discharge flow and the assimilative capacity of the River.

In order to address Kent County Levy Court’s concerns, DNREC agreed to cooperate with the county and collect additional field data and, if necessary, modify the model so that its predications would be in closer agreement to field observations. 

The results of two field surveys conducted in September 2002 revealed that the model was in fact underestimating stream areas, tidal currents, and discharge flows for the Lower Murderkill River.  Following the update of the model using more recent data, a revised TMDL has been proposed.  This TMDL increases the loads of nutrients and oxygen consuming compounds that can be discharged from the Kent County Facility.  It also considers that surface discharge from Harrington Facility will be eliminated through the use of spray irrigation (except during winter months when spray irrigation of the effluent is not feasible).  The proposed revision will not change nonpoint source load reduction requirements. 

We will be holding the public workshop on August 12, 2004 at 3:00 pm at the Felton Fire Hall, 9 East Main Street, Felton, Delaware.  Copies of the draft TMDL will be available by request on or after August 5, 2004.  Your comments, questions and suggestions may be presented either orally or in writing prior to or at the workshop.  To present written materials, please submit them by email or by regular mail or facsimile to:

Hassan Mirsajadi
Watershed Assessment Section
Department of Natural Resources and Environmental Control
Silver Lake Plaza — Suite 220
820 Silver Lake Boulevard
Dover, DE  19904-2464
phone:  (302) 739-4590
fax: (302)739-6140