Does ultrasound work for bluegreen algae control at lower cell counts (1000 cells/ml)? This would be for MIB/G control.

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1 Question Does ultrasound work for bluegreen algae control at lower cell counts (1000 cells/ml)? This would be for MIB/G control. Answer No reason to think it cannot. However, if the geosmin or MIB is already in the water column, i.e., dissolved, then it will not remove the compounds. Do any of the speakers have experience with cyanobacterial blooms in rivers being used as drinking water sources? Unfortunately, yes. For these instances, we have generally relied on activated carbon and/or ozone to taste and odor control. How would you define an algal bloom, a trigger cell count number? There are a number of indicators that we use to define a bloom. Chlorophyll a concentrations greater than ug/l; Cell counts of a particular algal group or genus exceeds 15,000 cells / mls (NOT total cell counts of 15,000 cells / mls). Secchi depth falling below 1 meter, and not attributed to TSS The area of the Lambertville reservoir is approximately 22.5 How deep was the reservoir? acres, with a mean depth of 5.6 ft. and a max depth of 16.2 ft. (KC - Q during my presentation) (see slide #23, bathymetric map). TREATMENT - Would GAC Filtration (dual media) be adequate for cyanotoxins/geosmin/mib removal or is PAC required? This would need to be evaluated on a site-by-site basis, but PAC is more flexible with regards to dosage and intermittent use (when needed) - my opinion. Is there any surface vegetation surrounding the lake perimeter than could be used to harvest, absorb phosphorus before it enters lakes? The watershed around the Lambertville reservoir contains about 17% wetlands that help to absorb phosphorous. Expansion of these wetland/riparian "buffer" lands could be part of a longterm management plan - this would need to be carefully evaluated.

2 What were the temperatures of the (Lambertville) raw water throughout May - Sept? Does the ultrasonic treatment impact other biota in the water column? 2013: raw water at or near the intakes varied from 19.0 Co to 30.6 Co, with the low measured on 5/17/13 and the high measured on 7/19/ : raw water at or near the intakes varied from 20.2 Co to 26.6 Co, with the low measured on 5/13/14 and the high measured on 6/30/ was generally a cooler year but much drier, particularly over the late summer season. No. It was reported to us that it does not, although we have not tested for this ourselves. What media did you add to the filters? The Lambertville WTP filters are now mixed-media (sandanthracite). The original design was 12" support gravel and 30" sand ( mm). We removed 6" of sand and added 6 inches of anthracite ( mm) to the top of the filters. Are there any concerns using ultrasound on other life-forms - i.e., fish? Did you need State approval for the install? We did not seek state approval for installation. It had been reported to us that there is not an impact on other biota. What do Geosmin and MIB taste or smell like? What is noticeable about them? Odors from Geosmin and MIB are broadly categorized as earthymusty. To describe them in a bit more detail, Geosmin has been described as mud, earthy-corn-grassy and MIB is described as musty, basement-odor. Both MIB and Geosmin can be detected by humans at extremely low levels between 5 to 10 ng/l (parts per trillion). Would ultrasound help control algae growth before they become blooms? Can ultrasound be used as a "preventative" measure? Yes, it can be used in a prophylactic mode. That was the intent of the study. Only after the intake to the other reservoir was opened did it really become a response/reactive measure.

3 What is the problem if we have late aeration? If aeration is implemented too late in the season (I.e. when there are already anaerobic conditions at the bottom of the lake), it can mix large amounts of phosphorous into the water column, creating conditions that can cause blooms. If implemented in late winter/early Spring, the lake is generally in a natural state of destratification due to colder water sinking to the bottom of the lake. Also, if the "right" kind of algae are present to absorb the phosphorous (I.e. not cyanobacteria), the bloom that occurs may not be problematic - but it's best to start aeration/detratification while it is occurring naturally (if this is the case for your particular water body. There are also aeration systems that are designed to aerate the benthic (lower) level of the lake and not disrupt thermal stratification. Do you think water residence time plays a role in effectiveness? What is your cyanotoxin testing trigger criteria? Did elimination of chlorine in raw water affect CT times and inactivation of crypto and giardia? Any unintended consequences? What is "quenching"? Yes. There needs to be time enough for the ultrasonic waves to impact the cells and also for the cells to settle. Longer contact times should improve performance. For Lambertville, United Water follow the World Health Organization (WHO) guidelines (cell counts), as follows: Microcystis > 2,000 cells/ml Anabaena > 15,000 cells/ml Aphanizomenon > 15,000 cells/ml Combination of all potentially toxic cyanobacteria > 15,000 cells/ml. Raw water toxin testing when cell counts > 10,000 ; raw and finished water toxin testing whan cell counts > 100,000. also recommend routine ( monthly ) raw toxin testing whan visiblr bloom as additional precaution and move to finished water te4sting when raw water toxin > 1 ug/l. Not at lake Co. CT is all after filters. Same as in DBP analysis --add thiosulfate to quench chlorine.

4 What is jar testing? Is there any effect on benthic algal species with the sonic system? What is the MRL for the ELISA analysis? Who established the MRL, OEPA? Can you distinguish between algal cells and filaments (multiple cells) in your counts? Sometimes individual cells are so difficult to count. A lab procedure to test various water treatment schemes--in this case to test PAC products or to test algal cell removay. Good description in AWWA manual M37. We only saw one instance of a benthic organism (lyngbya). I can't say if it was effective or if the organisms weren't there. MRL for their test kit used by Lake County for microcystin is 0.15 ug/l as established by equipment manufacturer. Yes - using the proper microscope resolution. In our ultrasound study, we saw both filaments and bundles of Aphanizomenon. The ultrasound tended to de-bundle the colonies into individual filaments, which may have been the cause of the increased counts. Does the OEPA legally require all the notification events that you have mentioned? Yes. Eliminating potassium permanganate seems to go against some recommendations to limit the dose but still use the chemical at a level that will not lyse cells. Why eliminate? Some studies show that low dosages of permanganate do not cause lysing, while higher dosages do cause lysing. Other studies have shown lysing with 1 mg/l permanganate with a large increase in extracellular toxins by both ELISA and LC/MS analysis. It is possible that different strains of cyanobacteria, or the same strains under different conditions, may lyse cyanotoxins and lower concentrations than others. We recommend, to be conservative, to eliminate preoxidation with permanganate (and chlorine) unless it is really needed (in which case adequate monitoring is needed to inform treatment decisions for cyanotoxins). Does anyone still add chlorine pre-filter with the concerns of TTHM formation? Yes. We (American Water) do this on a regular basis, especially when manganese removal is an issue.

5 You have mentioned only copper sulfate as an algaecide with issues of copper carryover and resistance. Have you any experience with peroxide? United Water has considered peroxide based algaecides, but this would require permit changes, which are attainable, but the chelated copper liquid based products are working very well. Also, the chelated copper based products allow for an overall lower total copper content per application, due to a purportedly larger proportion of the cupric ion. EarthTec, for example, states 99.99% cupric ion in solution. Can these ultrasonics be applied /position within the treatment plant, specifically sedimentation? Yes. There are different configurations that will allow this. How did you determine where to place the master buoy? Have you considered treatment in the reservoir with noncopper based chemicals? This was based on the recommendation of the equipment manufacturer. Where were your monitoring locations? Within the reservoir at one or more than one site, or at the raw water intake sample tap? For the United Water Lambertville reservoir, we identified 4 major sites, along with the plant intake. Samples were taken at 1 meter intervals (lots of data!). Ultimately, we plan to scale back the overall amount of sampling, as we gain more insight to the value of the parameters and the locations.

6 Ohio EPA's SOP ["Ohio EPA Total (Extracellular and Intracellular) Microcystins - ADDA by ELISA Analytical Methodology, Version 2.0, January 2015"] includes lysing. If I understood correctly, your approach involved only measuring extracellular cyanotoxins (i.e., not lysing) when comparing to thresholds. How do you reconcile that with Ohio EPA's direction? OEPA does not recommand lysing for finished water but does for raw water. We recommend that thresholds be compared in the decision tree to extracellular cyanotoxin. The thresholds in the recommended decision tree are lower than OEPA giudance as well. However, we also recommend analysis of both total (lysed) and extracellular cyanotoxins in raw water to inform treatment decisions. The total data will therefore be available if OEPA wants to see it. How were DBPs controlled when oxidizing the toxins? Lake Co. is lucky to be able to control DBPs through enhanced coagulation and then use free chlorine with no issues. Data published in the literature indicates that often when cyanotoxins are found in treated water, the majority is intracellular (from breakthrough of cells into treated water). How does the Lake County SOP take into account the potential presence of intracellular microcystin exposure? We have not found that to be the case and OEPA does not recommend lysing in finished water and they reference that cells have been removed at that point. Does the (Lambertville) system use biofiltration? No - United Water Lambertville WTP does not use biofiltration. Are buoy systems NSF approved so that they could be utilized in treatment plant basins experiencing algal growth? Yes. They have NSF-61 certification.

7 Has there been any evaluation as to how utilizing UV as disinfectant will affect removal for cyanotoxins? A little data avaliable shows minimal removal with UV alone. if USEPA's microcystin health advisory number is at or near the detection limit for ELISA, wouldn't KMNO4 be helpful during low cell count conditions? What is the cost of 1 buoy? The residual needs to be pretty high to oxidize/remove the toxins. It is generally impractical to maintain a KMNO4 residual > 1 mg/l as may be needed. Please check with the manufacturers for pricing. There are different types out there. As a WRF presentation, I don't want to give commercial info out. If you need, please contact PIs directly and they can put you in touch with the manufacturer.