WHY IS MUDDY WATER A CONCERN?
Muddy water concerns:
1. not safety issue - utilities has assured us that water is safe and they can make drinking water out of a mud puddle.
2. phosphorus management is key management strategy for reservoir.
- imposed in reservoir limit of 0.05 mg/l
- imposed restrictions on new residential construction to limit run off to 0.22 lb/ac/yr.
- used development plan for swift creek reservoir that controls ratio of residential to other more intense land uses (sets
amount of impervious area for reservoir).
3. Muddy water is telltale for high levels of phosphorus in run off. If you can see it, it is bad. Graph above shows the
impact of muddy water (sediment) on phosphorus level.
- data from 2000 shows high phosphorus levels when suspended solids are not visible.
- expect significantly higher phosphorus loads if mud sediment is visible (20-50% sediment loading)
4. Reservoir data for tributaries(2000) show Little Tomahawk creek at 1.5 mg/l (260 ppm suspended solids - not visible)
are are 3x higher than in lake limit
- EPA guidelines for maximum phosphorus in surface water runoff is 1 mg/l. Creek data higher than EPA guidelines.
5. HAL has requested the data for 2001 be released,
6. HAL has requested this years phosphorus data for Otterdale creek and Little Tomahawk and Tomahawk creeks. (through Sep
7. High phosphorus levels can lead to taste and odor problems in the drinking water.
8. High phosphorus leads to plankton growth (algae) and reduced oxygen in water (fish kills).
9. Copper sulphate (a known carcinogen at high enough concentrations) is used to kill algae.
10. High sediment loads require extra chemicals to remove the sediment from the drinking water (higher cost).
11. When Falling Creek water treatment plant was shut down some 25 years ago, high treatment cost was cited by the county
for its closure. Twelve feet (12') of silt and sediment was at the base of falling creek dam at the time of plant closure.