Black Fly Problem in Silver Lake caused by DWP.
As you know, I had to use finesse and every Google trick in the book to get any response from the DWP about Silver Lake and why they were doing nothing about the drained quarry water. Finally I guessed at Joseph Ramallo’s email by using “first.last name@ladwp.com”, and Bob’s your uncle! He replied that he was too busy to answer me, but would have a minion do it. I emailed my questions to Carol L. Tucker. She replied 6 days later.
So four weeks after the reservoirs were drained, they got around to answering a few questions. My question in bold, her response is italic, and I make some comments after her replies.
1. Why didn’t you just adjust the chlorine instead of draining? The bromate had already formed in the water and adjusting the chlorine would not have any impact on the existing levels of bromate. The water needed to be removed.
No way to tell if this is accurate, as neither Carol nor I know chemistry. Nor did LADWP hire any outside chemist consultants for the poisoned water! I did find this, written by a chemical journal, which does not quote any chemists at the DWP, either.
LADWP is still studying what happened in the reservoirs, says Pankaj Parekh, LADWP’s director for water quality compliance, although experiments have confirmed that the critical components are bromide, chlorine, sunlight, and probably dissolved oxygen. Parekh notes that most of the literature on bromate formation focuses on managing it in treatment plants or as part of desalination of ocean water. “There is very sparse information available for the type of drinking-water scenario facing us,” he says, adding that the department is rapidly developing an appreciation for photochemistry.
I.E., they don’t know why the hell it happened, and certainly could have tried to adjust the chlorine.
2. Why hasn’t DWP begun to clean [Silver Lake], as they said they would? Upon draining the reservoir, the DWP was surprised that the floor was actually fairly clean. The amount of vegetation and growth on the floor and sideslopes of the reservoir was very limited. Crews worked on cleaning up the floor of the reservoir from March 24 through March28, removing foreign objects from the reservoir.
Well, of course it was clean, as we had those birds – the scaups and others, cleaning the water. You know, the ones that have now left or died. Duh!
But what were those “foreign objects”, that took 4 days to pick up?! Curbed LA said one of the workers said they didn’t find anything at all. I quoted earlier what someone from the Silver Lake Neighborhood Council website said. Which I’ll repeat, because it amuses me. :)
P.S. I know what they found in the bottom of the lake after it was drained ! Why worry about your property values just be happy you have a home.
Bugs after the jump!
So still a big question on what was in the lake! But Carol, since it’s already clean, the immediate urgent question is obvious: THEN WHY AREN’T THEY REFILLING THE LAKE RIGHT NOW? What happened to your “Best Management Practices”, Carol? Why delay in this dry season, when birds and animals are so desperate for a little water?
There is no logical reason for this delay. So one must ask, who stands to benefit from the dry reservoir, when the community and all the birds and animals are suffering? Someone who knows city politics will no doubt be able to tell me.
3. Are you treating the water seeping up from the ground in any way? The water in the middle of the reservoir is a combination of water that we have left in the middle of the reservoir because we couldn’t drain it any further, water that spilled from Ivanhoe Reservoir into the Silverlake Reservoir, and normal water seepage out from the banks of the reservoir. This pool of water is currently being used as a source of water to irrigate the grasslands adjacent to the reservoir. There is no need to treat this water.
Absolutely the right answer. We don’t need any more chemicals in this green earth. I was just checking, because, you know of the smell and all…and let me tell you a personal anecdote here.
Like most families on the east coast, we had a summer house at the shore. (I think every family should have a vacation home – there’s something about tossing your cares away and starting fresh that happens each and every year!) So anyway, each morning there was a litmus test: which way was the wind blowing? Because that really did determine what kind of day you’d have at the beach. From the east meant cool ocean air (we were only a few yards from the beach.) But from the west, from the bay or swamp area….get ready for hot sticky air and lots and lots of bug bites. Mostly mosquitoes – even out here, if one swoops by my ear, my hair stands on end. But gnats would bite, too, without a whine to warn you. Even worse were greenheads; they left not just an itchy bite, but an itchy welt.
Get ready for lots of bugs and bites this season, Silver Lake and Los Feliz! The shallow puddle in the reservoir is just perfect for baby bugs. I’ve already written about the black flies, or buffalo gnats that breed in the LA River and then fly across the 5 to bite me when I’m running. Not that you have to run to find them… They started appearing in my apartment about 2 weeks ago. They hover around your face and nose, because, like the mosquitoes, it’s your CO2 they follow. So just don’t breathe out, and you’ll be fine. From the Entomology Department at OK University:
Humans as well as domestic animals may be viciously attacked. [snip] Livestock and poultry are sometimes killed by large numbers of black flies.
In addition, certain species are known to transmit leucocytozoon, microfilaria, and trypanosome infections in poultry.
Nice. (They also transmit bird flu, which might be one of those fancy words.)
How to reach the LADWP:
(213) 367-1361 No busy signal. Real person answers.
email: joseph.ramallo@ladwp.com
3 Comments
dlzc
Regarding your first question…
Bromate ion will naturally decay in a fairly short time. In labware, in a refrigerator, a high concentration solution decayed by 10% in a week. In stagnant water, organisms will harvest the oxygen from the ion to survive. Ammonia can be added in stoichiometric amount to achieve “breakpoint bromination” almost instantaneously.
It had not been reported in literature prior to this that *chlorine* can do this in the presence of visible light. Chlorine dioxide yes, but not chlorine.
However, this is a fairly tasty bit of PR, allowing public outrage to drive the necessary removal of this uncovered, non-compliant reservoir from the water distribution system. Harder to figure how they are going to sell the necessary enclosed (compliant) reservoir. And still have a “wetlands” appearance.
Donna
Thanks, dlzc!
So is there anything safe they can add to water to destroy any bromate? How about nature, such as fish or algae?
I’m not sure if I wrote some of this clearly about the wetlands part! According to the Environmental Report, they won’t close the reservoirs at all, just the pipes, which will lead the “real” water to the underground reservoirs at the Headlands, which is undeveloped land already owned by the DWP. I like that plan. They will let Silver Lake go natural!
dlzc
My apologies for the late response. I do check at least weekly, but Google did not show this thread until now.
Regarding your questions:
“So is there anything safe they can add to water to destroy any bromate?”
There are no “safe in any amount” compounds that could be added to do that, no.
“How about nature, such as fish or algae?”
Bromate is a carcinogen for a few species of mutant rats. It has been tested in the usual ways, and found NOT to be a carcinogen for many other species (not just rats), in levels thousands of times higher than found in this reservoir and for exposures of half an organism’s lifetime (a year). Bromate is found in Nature and most organisms have NO problems with it.
Bacteria will harvest oxygen from any compound, if it becomes oxygen deprived, such as being covered by balls and heated. This is how sulfate is converted to sulfide in the “swamp water” that many Floridians are forced to drink. But you usually don’t want these organisms thriving in yoru drinking water… pretty much why the chlorine was added in the first place.