Posts Tagged ‘water’

Guest Speaker: Megan Prelinger 
7pm, Monday April 18th, 2016
FREE Green Apple Books on the Park, 1231 9th Ave, San Francisco, CA 

In 2010, Megan Prelinger and collaborators Rick Prelinger and Stacy Kozakavich were invited by the Exploratorium to develop exhibits for the Museum’s planned Bay Observatory gallery. The Bay Observatory opened to the public in 2013, featuring dozens of research-based exhibits that combine the Museum’s legacy imperative to integrate art and science for the benefit of public understanding with a fresh imperative to explore the waterfront and the natural environment. In response to the Exploratorium’s prompt to “animate the Library in the service of understanding San Francisco Bay,” Megan and her collaborators created a series of graphic atlases that explain that histories of the watersheds and the shorelines, both natural history and the built environment. Watersheds and Shorelines are two of five atlases that also include Islands and the two urban atlases, San Francisco and East Bay. All are installed as permanent exhibits in the Bay Observatory, along with a public access mini library of Bay Area landscape history. In her April 18 presentation, Megan will show slides and discuss the research and outcomes behind the Watersheds atlas and the Shorelines atlas. Watersheds traces the flow of water from the mountains to the mouth of the Bay, and Shorelines traces the landscape of the water’s edge of both San Pablo Bay and San Francisco Bay.

Megan Prelinger is a cultural historian and naturalist. She is co-founder along with Rick Prelinger of the Prelinger Library and architect of its information design. The library is an independent landscape-based research library in San Francisco that has been open to the public since 2004. She is the author of several books, most recently Inside the Machine: Art and Invention in the Electronic Age (W.W. Norton, 2015), and the 2013 and 2014 Watersheds, Shorelines, and Islands historical atlases, all permanent exhibits in the Exploratorium’s Bay Observatory gallery.

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Brenda Goeden of BCDC and Ian Wren SF Bay Keepers joined us on August 19th, 2015 at the Exploratorium to to talk about what gets dredged out of the San Francisco Bay.

Most of the dredging that goes on in the bay is for navigation. This is mostly through mud — 80% of the Bay is fine grain mud, and it is dug out to allow deep draft vessels to come through, and keep waters by marina’s clear. The dredging aka mining of sand is mainly for the construction industry – it becomes cement, asphalt, road-base, sub-base and general fill. The grains of sand are grains (.002 to .08 inches in diameter) bigger than mud, and smaller than gravel. it gets mined on demand, not necessarily day in, day out.

There are two main areas whether the sand comes from: Suisun Bay and the Central Bay. Suisun Bay is a finer grain of sand which is often used for back fill in trenches. The coarser sand of the the Central Bay is used for cement. Sand is only found in the high flow areas of the Bay where the water has enough energy to carry the sand. Mud is taken out to the slow wide sides of the Bay.

Sand Flow in the Bay - Barnard et al. 2013

Sand is important for a number of reasons outside of its commercial uses — it helps build marshes and beach. It provides shoreline protection as it takes more energy to move, it provides a particular kind of habitat, and on the shore provides a place for recreation and having a place for viewing wildlife.

The amount of historical sand, and sand in the Bay is difficult to measure. Most of the sand in the Bay comes from the Delta and the larger watershed (40% of California’s watershed drains into the Bay), and estimated 1.2million cubic yards, with another 300+ thousand cubic yards coming from local streams. Where not blocked, the rivers and creeks, slide and bounce the sand along into the Bay.  Storms and other high flow events are key in moving the sand along and into the Bay and beyond.

The sand also is carried out into the ocean, and large dune field lays under water past the Golden Gate Bridge. This was once a wide delta of sand, but has been slowly growing smaller. This changing shape of this sand has affected how sand flows both inside and outside the Bay. The pattern of sand dispersal on Ocean Beach has meant the northern end of the beach has been gaining sand, and the southern has been losing sand leading to fast erosion of the shore. The bay itself is also losing some protection from ocean waves in this process as well. Crissy field on the other hand has benefited, gaining sand from both flows headed out to sea, and sand coming in along the shore.

There’s not a lot known about the habitat underwater in these sands. The Central Bay sand area is the deepest in the Bay 90′-300′ deep where the water is salty, deep, cold, and fast. Aka difficult to study (there has been some studies monitoring what is brought up by the sand miners). We know there are wondrous things going on down there, like the migration of Dungeness crabs — marching in to lay eggs, and then marching out again — but no one has ever seen it or knows the pathways.

Suisun Bay is shallower, warmer, and less salty. The two areas are pretty different, but in both cases these are deserts compared to the meadows of mud. The organisms living there tend to be smaller, efficient, and highly adapted.

Humans have had a huge impact on these fields of sand — the biggest being the pulse of sand brought down from the Sierra’s by gold miners, and estimated 10x the usual flow of sand. Before that, and before many of the rivers and streams were dammed. The flow might have been around 2 million cubic yards. The sand from mining continued to pulse through the system and is only recently pretty much all gone. Now a large portion of the pool of possible erodible materials is trapped behind dams and the delta tunnels.

We still have sand, and we still have sand coming in, but the question now is how much sand do we have, and how much can we afford to take out. Mining has been happening since the 30s, peaking in the years 1949-79. Much of the sand is used locally shipped to different dispersal points around the Bay.

Dredge mud goes to different places, a lot gets shipped and dumped out at sea, or dumped at certain disposal sites in the Bay itself (inside the bay this can disperse contaminants, cause turbidity). These are not the preferable options — that favored option (by BCDC) is helping restoration efforts, filling land that has sunk below sea level on the other side of levees. This is the unfortunately the most expensive option, which there are not a lot of funds for, and small marinas don’t tend to have funds to support that kind of work, and dredging for ports is an expensive enough business that any additional fees would likely be too onerous.

San Francisco Bay Keeper is involved in the issue, hoping to bring in the perspective of the overall health of the Bay and nearby waters, and the sand being an important part of it. The sand taken is not replenished, there is a net loss, and they want to make sure we keep relic sites, and keep mining more in active parts of the flow. They are also looking to insure there is proper compliance and that companies don’t end up taking more than they should. They are looking through commenting on proposals and active litigation to reduce the amount of sand mining going on — to being sand mining to a sustainable level.

On the flip side, if local industries turned to external sources for sand, there may be equally damaging impacts — leaving aside where the sand is being mined from, the carbon costs of shipping that sand by barge or truck would not be small.

The biggest question we seemed all left with was the complicated nature of the question. A unknown or at least unseen, but super valuable resource here in the Bay below us. How much is there? and how much can we afford to take out?

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Joel speaking at the Exploratorium

Joel spoke at the Exploratorium on July 15th, 2015 exploring in conversation and images “Seep City” – a catalog of water discoveries in the city of San Francisco.

Joel’s map of Seep City shows today’s landforms, but overlays the springs, water, and waterways of the past (I like how the map is a lacking in any streets — makes it funner to try and identify the places you know). Crissy field used to be much larger (the current marsh is a “sculpture of a marsh”), and there were large marshes on the eastern side of the city, a tidal waterway running up to the Mission District, and Islais creek wending it’s way into the peninsula. The sands also held many temporary lakes and water ways that would come and go with storms (and the shifting sands). They are barriers and dams, but could be blown away in a storm. Creeks flowing out of the dunes were often temporary or seasonal.

San Francisco — unlike a lot of cities — is not built on a river, and a question you might ask is why we have these seeps and springs at all. If you stripped all our human construction and put back features we’ve flattened or otherwise shaped, you’d find a lot of sand, as well as some serpentite and chert. Before all of our hardscape, rainwater would have been absorbed by sand and passed underneath it, but there is also water coming out of the tops of hills despite the drought. Joel still has yet to answer the question where this exactly comes from.

There were someplaces the water always flowed. The Ohlone, not a stone age people, but perhaps better described as people of the fabric age, made use of water based technology and had daily rituals washing in the creeks here. But there were only a few hundred there when the Spanish arrived.

The Spanish built their settlements in San Francisco around a couple of springs, in the Presidio and in the Mission. Captain Anza noted the spring that flowed out of the dunes near where the Mission was to be built was enough for a larger water wheel.

As the city developed, San Francisco used local water for laundries and for bottling, water was brought around the city through flumes built by private companies selling water to the more settled regions of the city. Lobos creek was one of the sources the flume running along the coast. Another had a water works that created stow lake. Safeway in the Mission/Castro area used to be a reservoir with water pumped over the hills from outside of San Francisco. Tank hill had a tank of water.

Water was also stored around the city for fighting the frequent fires of San Francisco’s early days. You may see the circle and square bricks circling intersections of San Francisco Streets. These continue to hold water for fighting fire.

Most of our water no comes from outside of San Francisco. The Presidio gets 80% of its water from its own springs. And lot of that water still flows, just mostly out of sight, channelized and covered over. There are of course many more water features now in the way of fountains and reservoirs, and some of that come from local water. The fountain in UN plaza (7 piles of stone representing the 7 continents apparently) actually runs on ground water that people refered to as Hayes Creek. BART has to pump water of its tunnels continually. Water runs under the Armory building in the Mission. There is a brewery at Haight and Steiner which hope to use the water underneath their store. The presidio has a creek you can shut it off in 3 places in case someone falls in.

This map is of course just a start, there are seeps and springs all over the city, and while this map holds many — Joel continues to hear of new possible springs and seeps. Keep up to date with this project at his website: seepcity.org

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This will be our first of three summer talks partnering with the Exploratorium Bay Observatory Gallery. Please note the time and directions. Please also call or email ahead to let them know if you are coming (see reservations and directions at the bottom)

Exploring SF’s Natural Springs & Creeks
Guest Speaker: Joel Pomerantz
7pm Wednesday, July 15th, 2015 (doors after 6pm)
FREE at the Exploratorium Bay Observatory Gallery (see directions at the bottom for details)
and please let them know if you are coming.

Bernal Seeps

Which is more likely in San Francisco: wading through a creek or through traffic? Under the right circumstances, either is possible to do. Sometimes, when atmospheric rivers slam the region, we can do both at once, as street gutters fill to capacity. But San Franciscan residents have few if any natural creek experiences. Compare that to the creek-dependent lives of the people that lived here for thousands of years before urban development and you might start to wonder.
Bring your curiosity and wonder for this discussion-oriented presentation by Joel Pomerantz, an independent researcher and publisher of the Seep City water explorations map. He will give tips on reading the landscape in search of water, and tell you where some of our beautiful (if small) springs are.
You can read some of the recent media coverage on wired.com or order a map on his website seepcity.org.
Reservations can be made at reserve@exploratorium.edu or 415-528-4444 option 5.
Please let the Gallery know if you are coming.
The lecture will be at the Exploratorium Bay Observatory Gallery at the back of the museum. The special event entrance is through the gate on the outside of building, past the main entrance (as depicted in the map). Someone should be out front helping guide (the museum itself will not be open). Please visit the Exploratorium website for directions to the museum.

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Joel Pomerantz (my partner in this lecture business) talked to us on March 19th, 2015 about his research into the flood of 1862. At first he did not find a whole lot, until he stumbled across the term “freshet”. That opened up a whole new line of research — which led to this wonderful and somewhat unconventional lecture — a “choose your own lecture” adventure: offering a list of topics on which he could speak.

Lithograph with frame K Street A Rosenfeld, SF

He did give some background to start. The term “atmospheric river” is a relatively new one. I hadn’t heard of it myself until I heard a lecture on drought last fall, but it popped up in the news a lot at the start of our winter storm cycle (the threat of which caused more chaos than the actual event this year). These rivers in the sky are actually the delivery mechanism for a lot of moisture from the the equator to landmasses. The moisture isn’t necessarily even visible from space only recently have microwave satellites been able to track them.

One of these rivers pushes up toward the northwest, and under certain circumstances, storms in Alaska (the results of other atmospheric rivers) push these rivers further south into California. The total water in these systems can be huge (10 to 20 Mississippi’s worth), and what fell in California in 1862 was exacerbated by a drought in the prior year, and a hard freeze that followed. What measurements we had: San Francisco saw 24”-37” of rain in January alone (19-20 is the average for the year). In gold country there was 108” in a month.

All this wrought terrible destruction, pretty much every mill, ferry, and bridge were washed out (many many deaths happened with people trying to cross rivers), tens of thousands of dead cattle washed up on beaches, low lying farms inundated, Sacramento flooded.

Newspaper accounts of the time (akin to the blogs of today) had all sorts of accounts of how terrible it was. Every day people thought it could not get worse, and each day it did. A Southern Californian woman recounted how in a 6 week stretch there was not time to dry even a handkerchief.

Given the prior year’s drought, sediment got picked up from the ground rather than the water being absorbed — and given also the blasting going on for mining, a tremendous amount of soil and rock was moved and polished by the high fast moving water.  Water covered 30’ high telegraph poles in some places and steamships were able to go anywhere.

The freeze that followed didn’t stop it. The freeze was a deep one down to sea level, but it didn’t stop the water from moving and ice tsunamis formed — ice piling upon ice, pushing up onto land crushing whatever might be in its path.

San Francisco Bay clocked no flood tides for over a week, raised as it was by 7’, and the water was fresh enough that steam ships didn’t have to trek to their usual freshwater streams to get water.

The effects did not happen all in one go either. Drought followed in 1863 and 600k more cattle died, pretty much the last of the stock that came from the original Spanish settlements. Michael Barber of UC Davis thinks that this is when native grasslands were supplanted, when new cattle was brought in directly from the east. Tree squirrels may have also taken their place at this time — so many ground squirrels were killed into the floods.

The greatest source of information about the floods comes from Sacramento. Governor Leland Stanford was inaugurated on Jan 10th, 1862 and was said to have had to row to the ceremony. Business had to be carried out on the 2nd floor of Sacramento, and 1000s of miners came down from the hills looking for a way back to San Francisco. A fair number of people turned their backs on California altogether.

The story quickly made its way into stories and song: Bret Harte’s Luck of Roaring Camp (the story was very successful, the author himself helped rescue people during the floods), a musician Max Zorer who named his songs after the flood (The California Flood Mazurka Dance), and a minstrel song published in 1863 called Down By the River Lived a Maiden, by H. S. Thompson, about a woman who drowns while chasing her ducks away from the river, which later was the inspiration for a song you are all familiar with Oh My Darlin’ Clementine. Joel gave a fabulous rendition of the original — an “old timey” sounding tune, with its amusing but ultimately sad lyrics (sadly my recording of this event failed entirely).

Down by the river lived a maiden

Joel had us speculate on why this disaster faded into the background, beyond the terminology, until recently there was little to be found on the subject. There is some level of time passing — we would not expect much of a history of Hurricane Sandy in 150 years perhaps, except that we are now building on the places that were designed as flood plains in the 1850s. His hypothesis is that it might be the flood control administrators who did not want to talk about it — the storm was of such a magnitude that it is unlikely we could build to it. It’s only recently that people have begun to think about a response (on such effort referred to as the Ark Storm). 16 million people live in areas which were underwater in 1862.

How long ‘til the next one? It is really impossible to say. There have been 2-5 storms of this magnitude in the last 2000 years (measuring from sediment layers taken from lakes). Ultimately, it is up to us citizens to remember, research, pass on, and act on this kind of knowledge.

At the end of the lecture, I am sure that Joel could have gone on much longer. Keep an eye on http://thinkwalks.org for updates and future talks on his flood research.

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The Most Extreme Storms Yet
Guest Speaker: Joel Pomerantz
7:30pm, Thursday, Mar 19th, 2015
FREE at the Randall Museum, 199 Museum Way, San Francisco, CA 

Joel will share his research on the weather disaster that determined so much of what’s around you today. In early 1862 the sky dumped upwards of ten feet of rain in the mountains (about four feet in San Francisco). In the middle of that, there was a hard freeze for a week down to sea level. Thousands died. No previous research has done so much to connect the dots. Come learn about the widespread disaster that spanned more than four states (before all were states), changed the course of rivers, destroyed the California economy and brought in invasive grasses, among other stunning details.

Sacramento in Flood

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(Notes by Joel)

John Scarpulla talked to us September 18th, 2014, about the Living Machine at the Public Utilities Commission (PUC) building SF Headquarters. John is a project manager, not an engineer. Very informative.

PUC headquarters: a well built building. Safe place in a quake. Command center for emergency operations. Features: Rainwater harvesting in preschool play area made of spongey material that’s permeable. Collects the water there and uses it to irrigate street trees.

The system called the Living Machine, a million and a half gallons per year. Not a large project compared to the 65 million gallons per **day** that the SF sewage treatment plants treat, but an example, a demonstration site. And a chance to test processes, including permits and ordinances. Wastewater treatment out in the open. Integrate technology into the neighborhood providing green in tenderloin.

Building is separately “dual plumbed” for potable water from the Hetch Hetchy system and wastewater internal system.

Water flows from primary tank to flow equalization tank to wetlands to building in a 48 hour loop. Flows from 7 to 7; none at night or weekend. Wetlands are in sidewalk, lobby and then the water cycles through the basement systerms.

Primary treatment tank is called and looks like a big “hotdog” and they needed a permit for that because it goes under the sidewalk.

First, a trash chamber separates things that shouldn’t have been flushed.

Second, a settling chamber removes a lot of the settleable and floatable solids. The solids are processed elsewhere. They don’t manage solids on site because the site’s too small.

The cycle is in waves, sending batches into the system with a 3000 gallon equalization tank. Recirculating tank for water available to go back to toilets is 6000 gallons. Wastewater treatment of 5000 gallons a day.

Nature wetlands, etc. process water by slowing the flow and cleaning the water but this speeds it up while cleaning it.

One way they do that is with “tidal” action. Water fills and then goes down like a tide every 58 minutes. Process quickly because the plant roots and soils are exposed to an influx of oxygen when water is low and organic microorganisms when the water is up. Most of the solids that were suspended in the water are removed by this process. Both aerobic and anaerobic bacteria involved. Self sustaining.

Ramped up population at the beginning, two years ago: Plants got inoculated then synthetic wastewater (milk solids and ammonia) were fed to it until real nutrients came into the system when building opened. Gradually reducing synthetic wastewater as human use increased so microorganisms kept stabilized.

Off gassing of nitrogen tells what population of microorganisms is like.

Department of Public Health (DPH) required wastewater to stay six inches below topsoil, so there are overflow vents to the sewer system preventing sidewalk overflows. Four inches under there’s a mesh to keep people from digging into the wastewater. No odors because subsurface vent sucks in and odors are emitted through a rooftop carbon filter scrubber.

Reasons particular plants were picked: Marsh plants can stand water in their roots all day every day. Must be tolerant of high nutrient levels. North side gets no sun. Plants have to be able to survive those conditions.

Landscape architect new to this but experienced engineer that has done this system before.

Batch sizes depend on whether it’s raining and day of the week. People are not in the building weekends.

Golden Gate Avenue side is the tidal flow wetland. Polk is the vertical flow wetland: one pass through of the water there first to cell 2a, then down hill to cell 2b. Light tan tint to the water after going through the wetlands. The filtering is then complete so it goes into the interior lobby plants which are a different plant pallet with species that like more sun.

“Acre Café” is in the lobby area twenty feet from the treatment.

There are pumps in addition to gravity. Twenty percent of California’s electrical and 30 percent of natural gas in the state is used for water systems. Living machine uses 75 to 90 percent less power than other systems available because they all use force through a membrane and this does not.

The water gets disinfected with UV light and a little chlorine in tablet form like a pool before it goes to the toilets again. There is one building in Toronto trying something similar that decided not to do chemical treatment and the mold growth became a public health and operational concern.

The system is entirely operated by computer from control room or from desktop computer or smartphone. Fully automated.

Aqua Nova specializes in wetlands.

DPW (Public Works) was involved because it was a large public building being built. Permits: No regulatory rules existed for this so they had to create some. DPH and DBI (Department of Building Inspection) and PUC signed letter of agreement. Will test yearly and inspect plus send results to DPH. Choloform, Turbidity, Oxygen load, etc. In the system itself, sampling is the biggest time draw. Otherwise little for humans to do to maintain it, oh except: Maintenance is big because warmth attracts sleeping, then there’s vandalism. People steal the plants and they have to be replaced.

Inreach wasn’t done as well as they wanted. For an agency of 2300 only about a dozen people came to the one inreach meeting. Outreach was good though.

Project purpose: help ask How can we get other building designers to rethink? In large residential, about half is nonpotable. 95 % in commercial buildings.

City ordinance introduced: Now any building in SF can reuse blackwater, graywater, stormwater (hits ground), rainwater (hits roof), or groundwater.

Amended an ordinance: Buildings can now share non-potable water between them but only by contract, whether paid or free.

If you go into the sidewalk you need a “minor encroachment” permit and it street then “major encroachment” permit.

PUC’s nonpotable guidebook is available from John. Grants from PUC are available for certain sized buildings to encourage development of more such systems or similar. If you expect to offset enough per year you get the grant.Moscone and Transbay and others will use from groundwater systems on sumps. Sump water doesn’t need all the plant cycle stuff, just filter and UV.

The Bullet Center and two military systems in San Diego are using black water, otherwise most systems that exist now are sump (groundwater) or storm water.

John Todd is the inventor of the living machine and calls himself an ecological engineer.

AAA Clifornia Automobile Association building had a groundwater system but was a failure due to high iron in the water. (Different locations have different minerals in groundwater.) gave them orange toilet stains so they only operated it a month. Redid building and took the system out.

In PUC building graywater and blackwater both treated combined, so it all is called black water.

Gray water reuse for homes was allowed as of last year by state law changes. Became okay for using indoors in January 2014.

Airport has a hidden and fenced-in staff building that does the same full system for blackwater but only 475 people work there.

Solar panels produce 12 percent of the buildings energy and the wind turbines 1.5 percent so easily covers the system pumps and UV.

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