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Home My Public Portal AboutJFOCP 2016-06-09VRANESH AND RAIS+CH, LLP VIRI ATTORNEYS AT LAW 1720 14th Street, Suite 200 Boulder, Colorado 80302 Telephone: 303.443.6151 Fax: 303.443.9586 www.vriaw.com JUT IaLTJ Eel t ,Io19181► I TO: Joint Facility Operating Committee ("JFOC") via Jeff Durbin FROM: Eugene J. Riordan DATE: June 2, 2016 RE: Copper Issues I. Recap The copper concentrations in our treated discharge are greater than the effluent limits in our discharge permit that become effective on May 1, 2017. Specifically, the average copper concentration in our treated discharge is about 17 WL and the permit limits will be: 8.1 jAgIL (daily max) and 7.3 L (monthly average). The low permit limits are based on the assumption that the plant will discharge at its maximum design capacity of 2.5 MGD (monthly average) when the river flow is at its lowest. As it turns out, this does not occur. Our highest discharges occur during the spring runoff season as a result of system -wide inflow and infiltration ("I&I") which is when the river flows tend to be higher. Additionally, since the copper does not occur naturally but instead is being leached out of the copper pipes in the buildings, the I&I actually dilute the copper concentrations in our discharge. In contrast, the copper concentrations in our treated discharge tend to be higher during our high occupancy season when there is virtually no I&I and the discharge flows from our plant are lower. As a result of this seasonality, additional treatment for copper doesn't appear to be necessary to protect water quality in the Fraser River.' Rather, there should be some recognition of this seasonality in the permit through the use of "monthly tiered limits" that better match the actual plant discharges and river flows. That is, the permit should ' Additional treatment could be expensive. Based on bench scale testing, it looks like the only sure way to achieve the permit limits is RO treatment which is not only costly (capital and O&M), it is also energy intensive which would significantly increase our carbon footprint. include a monthly limit for a range of discharges, not just the maximum design flow of 2.5 MGD. II. Discussions with the State Since the last JFOC meeting, we have discussed this issue with the state with some success. The state acknowledged the seasonal flows of the Fraser River and agreed to the monthly limit concept. The state also agreed that a "translator" should be applied when calculating the permit limits to ensure that those limits are consistent with how the water quality standard is measured. However, in order to obtain tiered limits, we would have to de -rate the plant capacity for the low discharge months which is a more extensive, time consuming, and uncertain process. If we don't de -rate the plant, it looks like we could meet the re -calculated monthly limits in every month but September through December. These are the low discharge months when the copper concentrations in our discharge tend to be higher. To address the compliance uncertainty in these months, the state has offered to extend the compliance schedule (which, in essence, will defer the effective date of the recalculated permit limits) to April 2018 so that we can further evaluate and take the necessary corrective actions to achieve compliance. III. Next Steps A. Permit Modification In order to finalize the state's recalculated permit limits, we will have to make a formal application for a permit modification. The simplest approach for this modification is to request monthly limits without discharge tiers. That way we don't have to go through the plant de -rating process. And, in light of the state's willingness to extend the compliance schedule, we will have some additional time to further evaluate options for achieving compliance with the recalculated limits during the months of September through December. B. Permit Renewal Our current permit expires on May 31, 2017. We need to file an application to renew the permit no later than November 22, 2016. Before completing that renewal application, we should consider the pros and cons of de -rating the plant generally or for just certain low discharge months to better assure long term compliance. At a minimum, issues that should be addressed include the following: 2 1. Even during our high discharge I&I season, our highest monthly average discharge has not exceeded 1.7 MGD. Without I&I effects, our monthly average discharge during the peak occupancy season is less than 1.0 MGD. 2. If we keep our current rated design flow of 2.5 MGD, we will have to install additional treatment to meet the Regulation 85 phosphorus limit as part of our renewal permit. If we reduce our rated design flow to 2.0 MGD, the Regulation 85 phosphorus limit won't be included in our permit until after May 31, 2022. 3. If we de -rate the plant, do we actually lose capacity for anticipated growth in the valley given the general reduction in average flows per SFE? 4. If we de -rate the plant, can we get the capacity back in the future if we need it? 5. Can we control I&I so we don't exceed 2.0 MGD during the spring runoff season and, if so, at what cost and on what schedule? 6. Can we meet the recalculated copper limits during the months of September through December through additional treatment at the plant or at the well head for the potable water supplies (to reduce leaching from the copper pipes) and, if so, at what cost and on what schedule? 3 State's Response to our Permit Modification Request Verbal approval for montly limits with a translator; no tiered limits without going through site approval Calculated new low flows as follows: the monthly flow averages for the facility were subtracted from the flow record at USGS gage 09027100 for a POR from May 1, 2011 through November 23, 2015. Result: Increased low flows but not at a consistent rate for each month. JanFebMarAprMayJunJulAugSepOctNovDec 1E3 (Acute)17/1218/1119/1223/1320/1617/1518/1317/7.310/7.910/7.413/1214/14 10E3 (Chronic)17/1218/1219/1224/1321/1820/1820/1317/1113/1113/1115/1215/15 Upstream ambient copper concentration was 1.1 μg/l; increased from 2012 WQA of .035 μg/l. Translator of 1.48 was applied. Tentative Results: Highest Highest estimated TR Current Current Recalculated copper value chronic, Acute, Chronic, μg/l Recalculated conc (2012-(assumes 10% μg/l PDμg/l PDTRAcute, μg/l TR2015) PDhigher) 7.38.124351617.6 Jan 7.38.1253619.521.45 Feb 7.38.1263816.217.82 Mar 7.38.1304411.112.21 Apr 7.38.127398.99.79 May 7.38.1233516.618.26 Jun 7.38.1243622.424.64 Jul 7.38.1243517.218.92 Aug 7.38.1152327.630.36 Sep 7.38.1152321.423.54 Oct 7.38.1192827.930.69 Nov 7.38.1203024.827.28 Dec Legend:Both chronic and acute fail Chronic fails Conclusions: 1This is helpful but doesn't completely solve the problem. 2Might be okay for Jan-Aug, but doesn't work for Sept-Dec; but we need to know how to translate our PD values to TR. 3State appears to be receptive to extending the Schedule of Compliance to a date certain to give us time to evaluate the Sept-Dec months. 4Let's take a closer look at our flows to determine if we can live with less than a 2.5 MGD capacity plant. Note: if we can live with 2 MGD, we can defer phosphorous removal for at least one permit cycle (delayed to May 2022). TR v PD data DateEff PDEff TRTR/PD%increase 5.3.166.77.51.1211.94 5.5.165.4 5.9.167.37.10.97-2.74 5.16.165.86.31.098.62 5.25.1677.41.065.71 ave % increaseroughly 10% Month of February Influent 2.50 2.25 2.00 1.75 FLOW PER DAY (MGD) 1.50 1.25 1.00 0.75 0.50 0.25 0.00 SATSUNSATSUNSATSUNSATSUNSATSUN MONTUEWEDTHUFRIMONTUEWEDTHUFRIMONTUEWEDTHUFRIMONTUEWEDTHUFRIMONTUEWEDTHUFRIMONTUE 20102011201220132014 Plot of Monthly Ave Flow for Jan-Dec 3.000 Permit Limit is 2.499 MGD 2.500 2.000 Flow MGD Max (2004-2015) 1.500 (Monthly Ave)up to 2.5 Average (2004-2015) 1.000 Looks like the base flow without I&I is less than 1 MGD 0.500 jan to dec 0.000 123456789101112 Months (January - December) NOTE:These flows demonstrate that flow equalization really doesn't work during the high flow months (April-July). Flow equalization addresses the weekend high flows only. And, during the base flow times of the year (Aug-Mar), we really don’t need flow equalization since the limit is a 30 day average. Renewal Permit Issues 1. Our highest monthly average discharge has not exceeded 1.7 MGD. Without I&I effects, our monthly average discharge during the peak occupancy season is less than 1.0 MGD. 2. If we reduce our rated design flow from 2.5 to 2.0 MGD, the Regulation 85 phosphorus limit won’t be included in our permit until after May 31, 2022, which would allow us to defer about $8.0 million of additional treatment costs. 3. If we de-rate the plant to 2.0 MGD, do we actually lose capacity for the actual sewage flows from the anticipated growth in the valley given the general reduction in average flows per SFE? 4. Can we control I&I so we don’t exceed 2.0 MGD during the spring runoff season and, if so, at what cost and on what schedule? 5. If we de-rate the plant, can we get the capacity back in the future if we need it? 6. Can we meet the recalculated copper limits during the months of September through December with additional treatment at the plant or at the well head (to reduce leaching from the copper pipes) and, if so, at what cost and on what schedule?