Big Muddy River TMDL-Appendix P
Final Report 12 October 2004
segments. When these areas were added together, it resulted in their estimate of total
lake surface area being approximately 50% more than it actually is. (p. 5-15)
Response: The entire volume of the lake was calculated based on historic depth and
surface area. Specific segment volumes were not calculated separately.
36. On p.5-6 and 5-7, it is stated that the correlation between pH and chlorophyll a is
expected to indicate a direct relationship between the two constituents. In fact Table 5-5
(p.6) shows that segment RNC4 has some of the lowest pH values for the lake and the
text indicates no individual samples with a pH impairment. Yet Table 5-7 shows
segment RNC4 with chlorophyll a levels more than double those of any other portion of
the lake. The actual data contradicts the hypothesis.
Response: TMDLs are supposed to account for all seasonal conditions within a
watershed, not specific events. Use of monthly precipitation takes into account that
requirement of TMDL development.
37. On page 5-7, it is stated that these relationships would suggest that controlling
phosphorus will in turn control pH. Table 5-6 (page 5-7) shows RNC4 with by far the
highest phosphorus levels for the lake, but Table 5-5 shows that segment to be in
compliance for pH. In fact it is the sampling segments which are well within the
standards for Phosphorus that have shown a few individual violations for pH. The actual
data again disproves the hypothesis.
Response: See response to question 21.
38. The computer model assumes that all cropland is immediately adjacent to streams.
That is definitely not the case in the Kinkaid watershed.
Response: See response to question 5.
39. The TMDL report states that there are no terraces in the Kinkaid Watershed. KAWP
2000 (page 11) reports more than 24,000 linear feet of terraces in the watershed (source –
Jackson County Soil and Water Conservation District).
Response: This statement has been deleted from the report.
40. In 1991, 1995, and 1996, the text (page 5-6) reports a total of three individual
samples slightly below the lower pH limit in the discharge below the spillway. Table 5-
4 (page 5-5) reports a total of 70 samples from this location over a seven year period. In
1991, 1994, and 2000 the text reports a total of 4 individual samples testing slightly
above the upper limit for pH in segments RNC1 and RNC3. Table 5-4 reports a total of
77 samples taken from these locations over an 11 year period. Do these data indicate any
consistent trend toward pH violations? Is it possible to question the accuracy of the
instrumentation or readings for pH?
