HYDRO28507

• Permit No: C1981010
• IBM Index Class Name: Hydrology
• Doc Date: 7/1/1991
• Doc Name: CDPS RATIONALE- AMENDMENT 1
• Permit Index Doc Type: NPDES
• Media Type: D
• Archive: No

COLORADO DEPARTMENT OF PUBLlC HEALTH AND ENVIRONMENT, Water Quality Control Division
Rationale -Page 7, Permit Na. CO-0032115
Table V-8 -Self-Monitoring Resells jor Outja11015
No. of Reooried Previous No. of
Parameter Ptriods- Av¢/Milt/Max. Limltalion Exeuri
Flow, MGD
30day avg I 0.0010 None -
daily rttax I 0.0129 None -
TSS, mg/l
30day avg 1 150 35 •"
daily max 1 150 70 •'
Total Iron, mg/f
30-day avg 1 5.60 3.5 •*
daily max / 5.60 7.0 0
Settleable Solids, mf/1 1 <0.1 0.5 0
Oil & Grease, mg!( 1 None Visible IO 0
pH, s.u. 1 -/8.3/8.3 6.5-9.0 0
Total Dissolved Solids, mg/f ! 230 none -
Whole EfJluertt Toxicity, Acute
Cenoda hnia dubia 1 > 100% > 100% 0
ate meow 1 > 10096 > 100`% 0
*• See section V.B.1.
1. Stale Samolintt: State sampling occurred at outjall 002 on July 14, /995. Results are summarized in Table V-9.
Table V-9 -State Monitoring Resuks jor Oatfa[1001
Reported :. Permit .. No~ of:.
-
Parameter' Concentrations - Limitation -Ezeurswns
Flow, MGD 0.066 None -
TSS, mg/P <10 35 0
ToJa! Iron, mg/! 0.073 3.5 0
Oil & Greose, mg/P None Visible !0 0
yH s.u. 8.4 6.5-9.5 0
B. Compliance With Terms and Conditions of Previous Permit
!. EfRuent Limitations: The data shown in the preceding tables indicate that the Trapper Mining, lnc. facility has
maintained compliance with the previous permit. Outfalls 008, 010 and Oll excteded the TSS limitations jor the
second calendar quarter and outfall O1S exceeded TSS and total iron limitations jor the same quarter. However, the
permittee claimed and was granted a storm exemption, thus these exceedences were not actual permit violations.
They met the applicable settleoble solids alternate limitations, as shown in the tables.
2. Ocher Permit Reouirements: The permittee has been in compliance with a!! other terms and conditions ojthe
permit.