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| | | Supreme Being
Group: Forum Members
Last Login: 6/26/2008 6:47:13 PM
Posts: 119, Visits: 602 |
| | I would just like to know what other people are dealing with. I am just trying to find our if there is some thing odd coming down the pipe. We have: May 1-Oct 31 20mg/l monthly average, 30 mg/l weekly average for BOD and TSS, ammonia - 2.0 mg/l daily max and 1.0 monthly average, and Residual chlorine - 0.05 mg/l daily max, 0.02 mg/l monthly average. November 1-April 30 30/45 BOD and TSS, ammonia 5.2mg/l daily max, 3.0 monthly average and residual chlorine drops to 0.04/ 0.01 E. coli - 126/100ml, pH 6.0-9.0, and 85% BOD and TSS removal Temperature - This is the fun one! June 1-September 30, 0.3*C temperature increase using a mass balance where the temperature of the river never exceeds 69.8*F. October1-14 max river temp.of 65*F, Oct 15 River temp. drops to 55.4*F, but if the 60 day rolling average river temp is less than 55.04*F, the allowed temp increase is 0.5*C and when the 60 day temp of the river is less than 55*F a full 1*C increase is allowed. Come May 15 the temp increase drops to 0.3*C and river max temp is 65*F and then it is back to June. There is a big question with our regulators as to what % of river flow we get to use it was 25% but after cumlitive effect analysis we may get 100% I know these limits don't seem very tight to some of you, but this plant has not been upgraded since 1972 ansd was only made to treat BOD and TSS. |
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| | | Supreme Being
Group: Forum Members
Last Login: Yesterday @ 9:25:30 PM
Posts: 372, Visits: 710 |
| I hate to sound ignorant (obviously the regulators know a lot more than me), but how do you adjust your effluent temperature up or down?
David |
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| | | Supreme Being
Group: Forum Members
Last Login: 7/3/2008 10:01:41 AM
Posts: 101, Visits: 1,074 |
| With a snow making machine? |
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| | | Supreme Being
Group: Forum Members
Last Login: 6/26/2008 4:01:08 PM
Posts: 156, Visits: 1,477 |
| | In New York, most of the temp. criteria were developed by fisheries biologists, and incorporated into the regulations. In the case of trout streams, effluent limit is 70 deg. F., and during the summer, cannot raise the stream temp. by more than 2 deg., or in the winter, by more thyan 5 deg. There are also other criteria that take into consideration cross-section area of the stream, mixing zones, etc., and models that can be used. In the bigger streams, where issues usually revolve around power plants, there are other criteria to prevent sudden changes in temp. (such as rapid shutdowns of cooling water), which can cause thermal shock. Realistically, we know that an STP doesn't have a lot of control over temp., but normal effluent temps. aren't usually a problem. It does mean that you shouldn't propose lagoons to discharge to a trout stream, where you know that come August, there will be issues. Similarly, may play into siting and permitting for projects. If there is a high temp. due to an industrial discharge, it may force construction of cooling towers, or other measures. May also get into stream monitoring, to establish what are normal conditions, above and below discharge point. Although the reasons for the criteria are primarily power plants, the regs. don't make an exception for other types of discharges. Hope this helps a little. |
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| | | Supreme Being
Group: Forum Members
Last Login: 6/26/2008 6:47:13 PM
Posts: 119, Visits: 602 |
| | David, I can't spell the way we were going to cool the water but is sounds like - high poor ree ich recharge. Water is cooled as it flows through the ground to the stream or river. Our demo project worked, but the flow volume was too low to be practical. It also helps to reduce ammonia. mark |
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