GrokSurf's San Diego

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Archive for the ‘Environment’ Category

Keep up-to-date with San Diego Coastkeeper

Posted by George J Janczyn on August 5, 2011

Did you know you can have the latest San Diego Coastkeeper newsletters conveniently delivered to your email address? Just visit any page on the Coastkeeper website and look for the “Join Our Newsletter” signup form that appears. Here’s the latest issue (click image to see the whole thing).

 

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Mexico might receive Colorado River water via the All-American Canal

Posted by George J Janczyn on August 1, 2011

A proposal to build a turnout on the All-American Canal in order to convey some of Mexico’s Colorado River water to Mexicali, Tecate, Ensenada, and Tijuana during an emergency (like another catastrophic earthquake) disrupting the existing delivery system is being considered through the Colorado River Binational Discussions process — an ongoing series of discussions between Mexican and U.S. agencies working on Colorado River water supply and water management issues

[This account is based on a briefing on the Mexico-U.S. Binational Discussions given at the San Diego County Water Authority (SDCWA) Imported Water Committee meeting last Thursday, July 28 [agenda packet]. Colorado River Program Director Halla Razak delivered the update.]

_____________________________________________________

East of El Centro. The newly-lined All-American Canal is wide, deep, and swiftly flowing.

All-American Canal

The Colorado River is the main source of water for the state of Baja California. After the river enters Mexico, an aqueduct starting in Mexicali brings water west for Tijuana and other locales.

In the aftermath of the 2010 Baja California earthquake, the aqueduct and other canals were damaged, and for a time Tijuana was in a vulnerable position. Later, looking for ways to avoid dependence solely on the single aqueduct, Mexico expressed interest in using the All-American Canal to convey some Colorado River water to Mexico during emergencies so as to provide an extra margin of supply reliability.

The idea was presented at the Colorado River Binational Discussions and a workgroup was set up to work out a plan. Members of the workgroup are:

  • San Diego County Water Authority (SDCWA)
  • Imperial Irrigation District (IID)
  • Metropolitan Water District of Southern California (MWD)
  • Southern Nevada Water Authority (SNWA)
  • Central Arizona Project (CAP)
  • Various Mexican government agencies

For the next year or so the workgroup will work on design, permitting, and funding. It will also work with the International Boundary and Water Commission (which oversees the 1944 treaty with Mexico regarding water deliveries between the two countries) to determine terms and conditions for implementing the project, and the Bureau of Reclamation which coordinates the Colorado River Basin States’ input to the negotiations.

Ms. Razak indicated that the workgroup is looking at a connection with 200 CFS capacity beginning at the western end of the All-American Canal, near the turnout for the Westside Main Canal.

If all goes well, it is hoped that construction could be completed in early 2014.

Although the City of San Diego isn’t a member of the workgroup, it will have some say in the project because it owns a portion of the capacity rights in the All-American Canal. That’s another story in itself — here’s a fact sheet explaining it. San Diego shoulders some expense in maintaining those capacity rights and will be looking for an agreeable financial outcome should this project be implemented.

Background

The April 2010 Baja California earthquake, as many of us are aware, devastated Mexico’s water infrastructure in the region. An Earthquake Engineering Research Institute (EERI) newsletter said an estimated 300 km of canals were knocked out of service [link]. Details on the effects of the earthquake are documented in this EERI Reconnaissance Report.

What was the fate of the water heading toward the unusable canals? Would it just be diverted out to sea?

That brings us back to the Colorado River Binational Process. In normal times they work on long-term strategic issues but during the last year their main focus has been dealing with the impacts of the earthquake. The All-American Canal project was an idea that came recently, relatively speaking. An earlier development was a U.S. suggestion that Mexico be permitted to temporarily store up to 200,000 acre feet in Lake Mead, as summarized in this Colorado River Board report:

“…with the large magnitude earthquake that occurred in the Mexicali Valley in early April, water deliveries from a large number of the canals in the Mexicali Valley have been disrupted. To assist Mexico in coping with this situation, the United States has suggested that, in the interest of international comity and as a one-time program, Mexico would be allowed to store up to 200,000 acre-feet of water in the reservoir system in the United States this year and then be allowed to request the delivery of the stored water during calendar year 2011. […] Mexico has considered this offer made by the United States and is proposing that this offer by the United States be incorporated into a more comprehensive deal that includes the concepts that are currently being discussed by the two countries to pursue Bi-National projects that could benefit both countries.”

As things turned out, however, the temporary storage wasn’t much needed. According to Mark Watton, Chair of the Imported Water Committee, Mexico has been slow to take advantage of that offer because the farmers, not wanting to wait for canal repairs, began digging their own diversion ditches and were able to irrigate their crops.

Mr. Watton observed that wasn’t the first time Mexican farmers were able to wrangle some extra water. He said a number of years ago (mid 90s?) the Colorado River had surplus water and about 3 million acre feet (MAF) went to Mexico that year (the U.S. treaty obligation to Mexico is 1.5 MAF). Despite doubling the usual volume of water entering Mexico, Watton recalled, not a single drop made it to the Gulf. Why? The upstream farmers captured and used all the extra water.

A short video documenting damaged and then repaired canals and other water conveyance work was also played for the committee. San Diego County Water Authority kindly gave me a copy with permission to post it here (I added the credits at the beginning).

 

Posted in Colorado River, Environment, Videos, Water | Tagged: , , | 4 Comments »

What’s up with the Chollas Creek wells?

Posted by George J Janczyn on July 27, 2011

Wes Danskin, USGS Project Chief for the San Diego Hydrogeology Project, shares this update from the Chollas Park Monitoring Well installed under contract with the City of San Diego to study groundwater in that area of the San Diego Formation aquifer (for a page collecting all the project updates as well as other groundwater news click this link).

WHAT WE FINALLY INSTALLED
Depth of well screen (SC) and sand are listed

Well #6: SC: 29.5′-49.5′; Sand: 16′-56′
Well #5: SC: 140′-160′; Sand: 180′-119.5′
Well #4: SC: 330′-350′; Sand: 310′-372′
Well #3: SC: 520′-540′; Sand: 432′-585′
Well #2: SC: 760′-780′; Sand: 739′-814′
Well #1: SC: 1040′-1060′, 980′-1000′, & 920′-940′ w/a 40′ sump; Sand: 887′-1100′

DEVELOPING THE WELL
The 6 piezometers at the site were developed, meaning the drilling fluid was removed. The process involves pumping air down each piezometer, which bubbles the water mixed with drilling fluid up and out. The aquifer then refills the piezometer with water, and the process continues until water-quality parameters (conductance, pH, and turbidity) stabilize, indicating that we are extracting only native water from the aquifer. The small amount of water in #5 means that it was not well developed. The low yield of #1 means that it took quite a while and some artful use of air, hose, and patience to get it developed. After winter rains next year, we will go back and see if we can develop and sample #5.

SAMPLING THE WELL
All piezometers have been sampled, except #5 which is dry, and #1, which is taking longer because of the low yield of the fractured bedrock. Sampling of #1 will be completed later this week. A broad range of water-quality constituents will be sampled including major and minor ions, trace elements, stable isotopes of hydrogen and oxygen and radioactive isotopes of hydrogen (tritium) and carbon (C-14), and volatile organics. By analyzing these data we can infer the source of the original recharge, when the recharge occurred, and whether human actions have affected the water. Because the general chemistry of water in the San Diego area like most basins is fairly similar, dependent on the rocks and derived sediment that the water is flowing through, we find it helpful to analyze trace elements and other minor constituents of water to determine of groundwater flow paths. It is rare for water districts or individuals to test for these constituents because they are commonly not viewed as a health or water-treatment hazard. Note, the radioactive isotopes are used for dating the time since recharge and are many, many times below a health hazard.

We also sampled a shallow well downslope from SDCP in order to compare our shallow piezometer data with it.

WATER TABLE
Water table appears to be at about 240 feet; Piezometers #5, #6 are both perched water tables.

PHOTO
Thought you might like to see samples of the water from each of the 5 piezometers we developed. You can tell #6 needs some more development; its a bit cloudy.

But we got great water out of #1, yeah! Getting water out of that fractured bedrock had me a bit worried for awhile.

–wes

 

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San Diego stormwater management: public comment period is almost over

Posted by George J Janczyn on July 22, 2011

In late July with everything warming up, stormwater management may not be a high priority in the minds of many San Diegans but it’s probably not a bad time to be thinking about it since there aren’t flood emergencies to deal with.

Stormwater generated from our urban and suburban environment is a great challenge in many respects, but as observed in a report by the National Research Council, nearly all stormwater problems result from the loss of water-retaining and evapotranspirating functions of the soil and vegetation in the urban landscape:

“In an undeveloped area, rainfall typically infiltrates into the ground surface or is evapotranspirated by vegetation. In the urban landscape, these processes of evapotranspiration and water retention in the soil are diminished, such that stormwater flows rapidly across the land surface and arrives at the stream channel in short, concentrated bursts of high discharge. This transformation of the hydrologic regime is a wholesale reorganization of the processes of runoff generation, and it occurs throughout the developed landscape. When combined with the introduction of pollutant sources that accompany urbanization (such as lawns, motor vehicles, domesticated animals, and industries), these changes in hydrology have led to water quality and habitat degradation in virtually all urban streams.” (page 5 from the book)

Stormwater rapidly funneled from upstream developed areas has an impact on Mission Valley which itself has become a tangle of roads, malls, and parking lots

Historically our urban stormwater management has been mostly about getting rainwater away from roads, buildings, parking lots, and other impermeable surfaces into creeks, pipes, and channels as quickly as possible.

Broader environmental impacts have not been not ignored but as a pragmatic budget-minded operation the City’s ability to address every issue has been tested as it develops its stormwater management plan. Whether the City can find more ways to control flooding but also to slow things down and allow more water to be naturally and usefully retained rather than discard it as quickly as possible remains to be seen.

The final meeting in the series of public forums on the City’s Master Storm Water System Maintenance Program was held yesterday evening at the Mission Trails Regional Park Visitors Center. The forum consisted of a joint presentation by Jill Witkowski, Staff Attorney for San Diego Coastkeeper, and Bill Harris, Supervising Public Information Officer for the Transportation & Storm Water Department, each offering a slightly different perspective on the program.

(for an MSM look at the program see Mike Lee’s Union-Tribune report. See also this San Diego 6 overview)

The underlying goal, which everyone seemed to agree on, is for the City to get away from a short-term reactionary mode where flooding problems arise, ad-hoc projects are quickly drawn up, emergency permits arranged, and different things happen depending on who is in charge that particular year. Instead, the desired strategy is a twenty-year program that locks in an orderly process that generates perhaps 3-5 projects per year, is not disrupted by management and staff turnover, and incorporates the needs and interests of the community.

The challenge is to find a balance between long-term strategic objectives and site-specific project details.

Originally, a Program Environmental Impact Report (PEIR) was prepared last year but a Recirculated PEIR had to be written because of a Coastkeeper legal appeal and additional information that developed after public review of the original PEIR.

Coastkeeper's Jill Witkowski and Stormwater's Bill Harris share the podium

After the presenters gave their overview and discussion with the audience ensued, one topic dominated: adequate, meaningful public participation in the future when specific project details would be developed.

In particular, Coastkeeper’s Witkowski pointed out that significant and meaningful public participation requirements have not been written into the document plan even though verbal pledges have been made to that effect. It’s not enough just to guarantee public access to information about upcoming projects, she said, but a process for responding to public feedback on those projects must also be documented.

Bill Harris acknowledged the plan needs to incorporate such language and asked for patience saying that the issue definitely needs attention and language will be written in. As the meeting continued, some individuals expressed lingering uncertainty about that documentation happening, while Harris expressed equal certainty that those desired changes will be made.

Seeing these people interact in the same room my sense was that the members of San Diego Coastkeeper and staff in the Stormwater Department are smart people who have engaged in sincere and constructive dialog with a great deal of mutual respect. I was a little startled to see a Coastkeeper publicity blurb suggesting the plan was designed “to avoid public input and prohibit neighbors from challenging projects” but I heard nothing quite that strong at the meeting. Indeed, Witkowski praised the overall plan and said it represented “a great step forward.”

After the comment period closes, it will take 4-6 weeks to read, digest, and write responses to the comments. The hope is then to place it on the City Council docket, perhaps at their October 25 meeting.

There’s not much time left for public comment. July 29 is the deadline for comments to be accepted for review and response. Comments must focus on the new issues in the Recirculated PEIR; no reponses will be made to issues from the original PEIR.

Even if you’re strongly interested in stormwater issues, it might be daunting to read the entire Recirculated PEIR and figure out where you might contribute worthwhile comments. You may not find time for all the apendixes, but perhaps scan the report and read through the responses to the original PEIR comments. Also, if you’re up for some nitty gritty, read on for extra perspective from both sides.

A San Diego Coastkeeper handout at the meeting outlined its view of the situation:

July 29, 2011: Last day to comment on “Program Environmental Impact Report” 1300 pages, 45 day comment period.

Fall 2011: City Council hearing to approve environmental documents and “Master” site development permit for 115 creeks and channels.

If approved, annual process:

  • City Stormwater staff develops “list” of channels for upcoming year. Presents list and previous year’s report to community planning groups and to City Council’s Natural Resources & Culture Committee
  • City Stormwater staff prepares individual maintenance plans. Hydrology, water quality, noise, historical, mitigation
  • City Stormwater staff sends detailed plans to City Development Services Department for approval
  • Development Services uses Substantial Conformance Review checklist to determine if new, greater impacts in environmental review for program

If no and NOT in Coastal Zone, then Process One = DSD approval. “Courtesy” public notice to community planning group in area; no public comment period, no hearing, no appeal process.

If no, but in Coastal Zone, then Process Two = DSD approval. Notice of future decision to community planning group and residents within 300 feet; DSD decision made within 11 days of mailing notice (can extend to 30 days if CPC requests extension before decision is made); Notice of decision to people who request it no later than 2 days after decision date; residents/CPC can appeal to Planning Commission if appeal within 12 days after decision.

If greater/new environmental impacts, then Process Four = Planning Commission Hearing. Notice of application to CPC and residents within 300 feet plus those who request notice; Planning Commission hearing where public can weigh in on the projects; Appeal to City Council within 10 days of Planning Commission decision.

The City’s draft PEIR has this take on the situation:

“Although the Master Program has been amended to require hydrology and hydraulic studies be completed for each of the individual storm water facilities at the time maintenance is proposed, some of the members of the public are expected to insist that hydrology and hydraulic studies be completed for all of the storm water facilities before adoption of the Master Program. In addition, members of the public are expected to insist that detailed maintenance plans be identified prior to approval of the Master Program and PEIR to assure that the impacts are adequately anticipated.”

In response to concerns expressed regarding maintenance in open space, the City’s Storm Water Division (SWD) removed many of the storm water facilities within open space where maintenance was not likely to be required. As a result, the number of miles of storm water facilities included in the Master Program was reduced from 50 to 32 miles. In addition, SWD has determined that the estimates of disturbance width in the original PEIR was over conservative. With the reduction in the number of storm water facilities combined with the reduced disturbance width assumptions, the impact to wetlands within the City’s jurisdiction would be reduced by approximately 43 percent (30 acres) when compared to the original Master Program. Nevertheless, some members of the public are expected to request further reductions in the number of facilities to be maintained under the Master Program.

Concerns are likely to continue to be expressed regarding alternatives to the proposed maintenance. Although the City’s DSD staff believe that a reasonable range of alternatives is presented in this PEIR, members of the public are expected to contend that other alternatives exist to the proposed project.

Water quality is also expected to continue to be a concern of the public. Although the water quality discussion has been expanded in the PEIR, members of the public are expected to take the position that the water quality impacts are understated and that additional mitigation should be proposed.

In addition, the public has expressed a desire to have more involvement in reviewing annual maintenance proposals which are required as part of the Master Program. In meeting with these individuals and groups, the City has cited specific CEQA statues and guidelines and San Diego Municipal Code regulations to support their determination that annual maintenance activities that are explicitly identified in the Master Program and adequately addressed in the Final PEIR can be approved in reliance upon the certified Final PEIR. As described in Subchapter 1.6 of this PEIR, pursuant to Section 15168(c) of the CEQA Guidelines, the certified Final PEIR would satisfy CEQA requirements for subsequent maintenance activities if no new effects could occur, no new mitigation measures would be required, and all feasible mitigation measures or alternatives identified in the PEIR will be implemented. Despite the legal grounds for maintaining that no new environmental document is required for annual maintenance plans covered within the scope of the Master Program and adequately described by the PEIR, members of the public are expected to push for such review regardless of the provisions of CEQA.”

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A brief talk about the USGS San Diego Hydrogeology Project

Posted by George J Janczyn on July 12, 2011

A few weeks ago I visited the site of the USGS monitoring well being drilled at Chollas Park. The well is part of the USGS San Diego Hydrogeology Project studying water quality, quantity, and flow characteristics in the San Diego Formation aquifer (click here for the story from the visit).

Here’s Project Chief Wes Danskin discussing the program with San Diego KGTV Channel 10 reporter Joe Little (apologies for the less-than-perfect camera work):

 

Also, here’s Joe Little’s report on 10 News.

 

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Legal challenge continues over SDSU’s Master Plan and Adobe Falls development

Posted by George J Janczyn on June 21, 2011

This is to catch up on the multi-year legal maneuvers that involve the Adobe Falls area — undeveloped open space adjacent to Alvarado Creek just north of the I-8 freeeway across from San Diego State University, west of College Avenue. San Diego State University’s Master Plan intends to develop that land with up to 348 residential housing units for faculty and staff.

Alvarado Creek (the green tree belt) crosses to the north side of Interstate 8 near College Avenue. The Adobe Falls cascades wrap to the north and then the creek turns westward.

Beginning with the 2005 Master Plan and then the 2007 Master Plan revision, California State University’s certification of the Environmental Impact Report (EIR) was challenged in lawsuits by the City of San Diego, Del Cerro Action Council, and other entities.

February 2010: after years in court during which the cases were consolidated into one, the Superior Court entered a judgment in favor of SDSU (for history up to that point click here).

Subsequently, the City of San Diego and its Redevelopment Agency, the San Diego Association of Governments (SANDAG), and the San Diego Metropolitan Transit System (MTS) decided to appeal the decision (due to lack of funds, Del Cerro Action Council was unable to join the appeal).

December 2010: City of San Diego and other parties filed opening briefs in their appeal of the Superior Court judgment.

February 2011: CSU filed its brief.

March 17-18, 2011: San Diego [et al.] filed reply briefs.

April 26, 2011: Amicus curiae (friend of the court) briefs were filed by California Department of Transportation, League of California Cities, and California State Association.

May 26, 2011: CSU filed responses to the amicus curiae briefs.

Del Cerro is in the background. Alvarado Creek's Adobe Falls, which flows year-round although sometimes at a trickle, is hidden at top right

The issues discussed in the various briefs go into considerable detail. Note that SDSU’s Master Plan includes other development projects in addition to the Adobe Falls proposal, so the mitigation issues discussed in the appeal are much broader. I would characterize the arguments very generally as going back and forth over the following:

1. The City asserts that CSU abused its discretion under the California Environmental Quality Act (CEQA) by claiming its financial obligation to ensure mitigation for traffic is limited to requesting funds from the Legislature. If funds were to be denied, CSU would assume no further responsibility.

2. SANDAG and MTS argue that CSU failed to address the impacts that will result from SDSU’s massive increased use of public transit systems to transport additional students, faculty, staff and visitors to and from the SDSU campus” and that CSU should have considered alternate potentially feasible mitigation measures.

CSU argues that it cannot make funding requests for highway traffic improvements, because only Caltrans can do that. CSU says the Master Plan project traffic impacts are just one part of the overall traffic growth picture that Caltrans must plan for. However, CalTrans presently has no plans for highway improvements in the vicinity of the project, so without such a plan, it would be impossible to determine what CSU’s fair share should be. CSU says it can only commit to pay a fair share for traffic improvements when Caltrans develops a plan.

Further, CSU argues that it prepared a traffic analysis that studied impacts to the transportation network surrounding SDSU as required by CEQA; identified significantly impacted intersections, roads, and road segments; negotiated extensively with the City of San Diego and other agencies over the fair-share mitigation amounts; made final fair-share determinations; adopted fair-share mitigation measures specific to both the City of San Diego and Caltrans; and requested fair-share mitigation funds from the Legislature. CSU says it changed its capital outlay budget process to include mitigation of off-campus impacts. CSU also argues that there is nothing in CEQA that requires “alternate potentially feasible mitigation measures” not required by statute or implementing regulations.

Naturally, everybody involved with the case declines to comment because it is ongoing litigation.

What’s next: a clerk at the Court of Appeals indicates that no further hearings have been scheduled, but guesses that it could be September or later before the next hearing.

One of several cascades at Adobe Falls.

 

Posted in Adobe Falls, Environment, Government, Land use | Tagged: , , , , , | Leave a Comment »

Chollas Park groundwater study: pictures tell the story

Posted by George J Janczyn on June 21, 2011

Here’s the latest from Wes Danskin’s log on the USGS groundwater study at San Diego Chollas Park (previous log entries on this study are here).

WHAT’S NEW
Done drilling, chose depths for wells (piezometers–pressure sensing wells), installed 2-inch PVC piezometers, and are developing of them as I write this. Decided to include photos of each activity so you don’t have to read all this, just view the photos.

CORING TELLS THE STORY
Hit bedrock (Santiago Peak volcanics at 877 feet). Core at 895 feet is shown below. Many fractures are present

PICKING THE DEPTHS OF PIEZOMETERS
Based on geophysical logs, drill cuttings, cores, pore water chemistry, geologic mapping, evolving concepts of groundwater flow, likely constraints to developing a water supply, defining the yuck factor of Chollas water, taking advantage of evaporating Chollas Lake water … one of the more difficult things I do. You definitely get your money’s worth from the Chief Scientist on the project (me).

Well #1: 1040′-1060′, 980′-1000′, & 920′-940′
Well #2: 760′-780′
Well #3: 520′-540′
Well #4: 330′-350′
Well #5: 140′-160′
Well #6: 30′-50′

DEVELOPING WELLS
Send air down the wells to force water and left-over drilling fluid up and out. In the photo you’ll see water being ejected from one of the wells.

As we extract water/drilling fluid, the aquifer replenishes the well water, which eventually ends up cleaning the well of our drilling effects. We monitor clarity of the water, pH, conductance, and temperature to known when we have removed drilling-related water and fluids and when we have native ground water. Great news is that the fractured well shown in the photo above makes water, not much, but makes water via those fractures.

NEXT STEPS
Sampling the wells for water quality.
Installing a vault to protect the wells.
Installing water-level monitoring equipment, and satellite link.
Putting the information on our website.

Whew, I’m exhausted; almost done.

–wes

 

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Site visit: USGS groundwater study at San Diego Chollas Park

Posted by George J Janczyn on June 7, 2011

Recently Wes Danskin, Project Chief for the U.S. Geological Survey (USGS) San Diego Hydrogeology Project, shared notes from his log (here and here) regarding installation of a monitoring well at Chollas Park that will be used as part of a study to learn about water quality, quantity, and flow characteristics in the San Diego Formation aquifer. Funding for the well comes from the City of San Diego.

Last Thursday I received an email from Danskin: “Stop by if you’d like, we’ll be on site for about another week completing the piezometer installation.” No need for a second invitation; the next morning I grabbed my camera and headed over to the project site.

The well is just west of Chollas Lake which itself is just west of the College Grove shopping center near the SR-94 freeway at College Avenue.

Several other visitors were already there, including a few members of the San Diego Association of Geologists (SDAG). 10News reporter Joe Little was there, preparing to interview Danskin for the evening news.

(all photos can be clicked for enlargement)

10News reporter Joe Little (left) prepares for the interview with Wes Danskin.

Wes animatedly talked about a new three-dimensional geologic map of the region that he’s been working on. No previous geologic studies in the San Diego/Tijuana area have produced such a map. According to the SDAG website (“Mapping the San Diego Underground”):

“A total of 91 wells, which showed stratigraphy older than Quaternary age, helped provide depth information to produce this 3D hydrogeologic framework model. This study relied on pre-existing GIS (geographic information systems) datasets including DEM (digital elevation model), surface geologic maps, drilling and e-logs, and literature references to wells or outcrops. Direct examination of USGS multi-depth wells provided the most reliable “ground truth” for geologic boundaries used in the model.”

Danskin explained there are three types of wells: 1) monitoring wells to identify water levels and quality and geology of the groundwater basin; 2) pilot production wells to determine the quantity of water flowing through the ground; 3) full scale production wells. For the San Diego study, the first two types are being used.

Continuing, Danskin said the San Diego Formation extends north-south from La Jolla to south of the border, and west-east from the ocean to the vicinity of the I-805 freeway. Groundwater has been extracted from the San Diego Formation for over 50 years. Sweetwater Authority has been distributing it to National City and Chula Vista.

“The important part about this well is that we’re actually able to get down into the hard rock,” said Danskin. “None of the other wells, with the exception of one near Qualcomm Stadium, were we able to identify this important part of the geologic story,” he said, noting that “the critical part of what we’re doing is defining how the geologic layers are arranged and that allows us to understand how the water moves through them.”

An interesting fact: using carbon dating they found that it could be up to 30,000 years since that groundwater was last in the atmosphere.

Little asked whether pumping and treating groundwater can be cost-effective. Danskin replied that Sweetwater Authority’s pumping of groundwater shows it is already cost-effective. It will gradually become even more competitive because the price of imported water continues to increase. It is becoming more attractive from a reliability point of view too, because we import up to 90% of our water from the Colorado River and the Sacramento-San Joaquin Delta, and both of those sources are climatologically, environmentally, and politically at risk.

Danskin said chances are that most of the water in the Formation will be salty and require reverse osmosis treatment…not as salty as the ocean but it may contain the same salt level as V-8 juice. Still he has an optimistic outlook about the project finding a reliable groundwater flow. “It’s taken about ten years,” he said, “but things are finally starting to make sense.”

A typical tricone drill bit.

Numerous soil samples are taken at regular checkpoints as the drill goes deeper.

Danskin discussing the various well locations in San Diego.

 

Here’s video I shot while Danskin discussed the project:

 

See also Joe Little’s report on Channel 10 News:

 

Posted in Environment, USGS, Water | Tagged: , , | 2 Comments »

A rocky search for water beneath San Diego

Posted by George J Janczyn on May 26, 2011

Last week Wes Danskin treated us to news (What’s percolating beneath San Diego?) on the new USGS deep monitoring well at San Diego Chollas Park (SDCP), part of a study of the geology and groundwater resources in the coastal San Diego area.

Here’s the latest from Wes’s log:

 

May 17: Every picture tells a story

Picture of our core at 580 feet depth

May 20: Sounds of silence

Drill rig broke yesterday; frayed the cable supporting the kelly head; dangerous not to replace; so we will.

A core we obtained from 665 feet; looks like Friars Formation to me

May 23: 875 feet, no, not yet

We all underestimated the depth to bedrock, even the drillers.

STATUS
Sunday night, at 875 feet deep. Maybe in the top of the weathered bedrock. Cuttings appear to be ground-up rock; drill times are longer, but not so long to indicate hard rock, I think. Taken cores along the way, every 150 feet or so, most recent: 440, 580, 665, 860 feet.

FUTURE
Will continue drilling, until we once again think we are in hard rock, probably the Santiago Peak Volcanics, then take a core, to make sure it is what we think.

I’d like to get 1 or 2 piezometers deeper than the production zone of National City well field, which has been producing fresh water for 50+ years. Bottom of those wells is about 700 feet below sea level; presently we are at 550 feet below sea level. Good news is we have covered the majority of the production zone, so if groundwater is flowing roughly horizontally to the coast, we will be able to sample the upgradient side of the flow field, or at least a similar flow field a bit north of the National City wells. Bad news is that drilling another 450 feet (150 to bottom of zone + 300 feet) will not be easy. But our drilling is about patience and flexibility. So we’ll see how it goes.

May 25: Bedrock and beyond

STATUS
Yes, we hit bedrock, finally, at 877 feet. And we have proof, as shown in the photo below (core of the Santiago Peak Volcanics, … same rock as what the coastal dams are anchored in). Note the fractures and related water deposits, such as calcite shown at the point of the pen. This deposit demonstrates water flow through the fractures, albeit, we don’t know when.

In the process of squeezing the sediment that we obtained via coring. Short answer I think is that the pore water is more saline (ec = 1800; tds = 1000) than I would have thought/hoped. A bit confused by why we are not seeing any 600 tds water like National City wellfield. Darn. Answer may change a bit when we install the piezometers in the more transmissive zones.

FUTURE
We’ll continue drilling in the bedrock with the goal of getting deep enough (200+ feet) to install a well, hopefully with sufficient fractures to yield water. I have a plan for 5 piezometers: 3 inch to the bottom to monitor changes in salinity and temperature; 2-inch for the other 4. Estimated completion without geophyscial logs, etc are:

	          5. Water table at 50+ feet, 
	          4. Below water table at maybe 250 foot depth in stadium conglomerate, 
	          3. Something in middle 400-500 foot zone, 
	          2. One in Friars formation at 700 feet, and
	          1. One at bottom in Santiago Peak Volcanics at 1000+ feet.

Core of the Santiago Peak Volcanics, same rock as what the coastal dams are anchored in

PHOTO BELOW. Bill Elliott, SDSU professor and local gravity/geology guru; and Adam Kjos, our local USGS man on the spot, supervising the drilling. Both are trying to figure out from the drill cuttings what might be going on, e.g.,

  1. What formation are we in, where
  2. Why the 600 feet thickness of stadium-like coarse deposits are present
  3. Whether sand at 700 feet might be the Friars formation, or something like it
  4. The weathered zone above the volcanics appears to be about 60 feet thick
  5. Do any of these geologic units really correspond to geologic units mapped at the land surface?

Thanks to Bill Elliott for coming to the drill site and sharing his expertise in local rocks to help us understand what we might have been drilling through, and to Dave Schug from URS for similarly stopping by, though I was not on site then to take photos and quiz him.

 

Postscript May 31, 2011

STATUS
Reached the end of the line, 1100 foot depth. Every well sort of tells you when it is done giving up secrets. When drilling took more than 3 hours 20 minutes for each 20 feet, we decided to call it a good effort. We have obtained much new information, and whatever else we could gain from drilling deeper into the Santiago Peak Volcanics, probably is better done at another location, starting in bedrock and using air rotary technique.

GEOPHYSICAL LOGS
After reaching 1100 feet, based on my request to get a good 100+ feet into the Santiago Peak Volcanics so that we can complete a well that will reliably yield water, we stopped, cleaned the well, and called in our geophysical logging experts over the weekend (never a holiday for anyone associated with drilling; got done logging at 3 am; thanks Tony and Mike).

The geophysical logs are attached so that you can see for yourself the variation in material. Don’t worry; you don’t have to understand the logs or what they mean to get the basic idea. When the squiggly line changes, that means the earth or the water quality has changed. So at a first level, big picture analysis, look to see where the lines change once or twice or three times in the span of 1100 feet. Bet you can pick out where the bedrock starts. Say 877 feet. Another package of material is from about 440 to 600; I’m guessing alluvial fan based on cuttings and drilling notes; and another unit, mostly sand, from 600 to the weathered bedrock at about 800. But the SP log shows two zones within that last zone, so again this is not so precise as to become boring, or a single answer wins. Will know more, or think we do, after several hours of analysis by several of us.

NEXT STEP
We’ll be starring at the geophysical logs, the cuttings, the drilling notes, the locations of core samples, and using our Ouija board to divine where to place the piezometers. Let you know in the next couple of days the precise well design.

In the meantime we are reeming the 7 7/8-inch pilot hole, first with a 13-inch bit down to about 350 feet to accommodate two piezometers above that level; then with a 10-inch bit down to 820 feet to accommodate 2 more piezometers above that depth, then with the 7 7/8 inch bit to clean out the debris that fell in the hole down to the total depth of 1100 feet.

The rationale for drilling a pilot hole first is that a smaller diameter hole can be drilled faster, circulation time is faster, the geophysical logs will be better, and there may be fewer problems with caving. The bad part is we will spend 4-6 days redrilling the well to make it the size needed to install piezometers. If we knew the geology ahead of time, then perhaps we could design the general size of the well bore ahead of time and only drill the well once. But in San Diego that knowledge does not yet exist. Getting there though. The geologic framework model that Carolyn and Claudia are preparing shows that we are getting to where drilling will be less wild-catting and more predictable engineering.

 

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What’s percolating beneath San Diego?

Posted by George J Janczyn on May 17, 2011

Wes Danskin, the Project Chief for the USGS San Diego Hydrogeology Project has been busy studying what’s going on underneath San Diego. Late last year he updated us with work underway at that time. Now he’s working on a new project with a deep USGS monitoring well:

———————————

May 15, 2011:

That time again. Another deep USGS monitoring well is being installed. This is the first in a series of updates.

WHO
The United States Geological Survey (USGS) is partnering with the City of San Diego. Many thanks to Greg Cross, George Adrian, and Marsi Steirer of the City Water Department and to Keith Selby and Mike Morrow of the City Park Department for their critically important help in getting this project going.

WHAT
A deep multiple-completion well is being installed to help define the geology and groundwater resources in the coastal San Diego area. This and prior USGS wells are described on the project website, http://ca.water.usgs.gov/sandiego. This well is referred to SDCP (San Diego Chollas Park).

WHEN
Started May 10, will continue through about June 10.

WHERE
Chollas Community Park, toward the westernmost end, just east of 54th Street. Drilling in the North Chollas Community Park parking lot, in a median between parking stalls, about 50 feet from a drainage from Chollas Lake.

WHY
To define the groundwater flow paths from the eastern part of San Diego County, to the western part where additional groundwater extraction likely would occur. The geochemical water samples that we have collected previously from coastal wells (stable isotopes of hydrogen and oxygen) suggest that the source of the groundwater is recharge from precipitation not on the alluvial plain of the coast, but further east, such as near El Cajon, or further east. This means that the groundwater would need to flow through hard rock (granites, and Santiago Peak Volcanics) in order to reach the coastal sediments west of about Interstate 805.

This well site in Chollas Park (SDCP) was chosen to be east of the La Nacion fault which is approximately 54th street. This site means the drilling will penetrate some unconsolidated sediment (maybe 500 feet), and then penetrate the hard rock. Ideally, the total depth of the drilling will be about 1500 feet. Completion of the well with about five 2-inch PVC piezometers will allow us to sample groundwater from different depths and better understand the groundwater flow system.

Another well site, referred to as SDHF is located at the intersection of Home Avenue and Federal Blvd, and is on the down-dropped west side of the La Nacion fault. These paired wells (SDCP and SDHF) will aid us in understanding groundwater flow from east to west across this major structural feature in San Diego.

SITE VISITS
Are possible by contacting me.

PROGRESS TO DATE
Will give more details in a subsequent email, but the short answer is that at about 2 pm on Sunday, we were at 410 feet in a sandy, clay, ready to take another core.

Rough stratigraphy, from my memory:

Depth — Geologic characteristics

10 feet — Sandy fill.

20 feet — Santiago Peak gravel. Scared us, thinking we maybe already hit bedrock, but it probably was gravel eroded from a construction project upslope.

40 feet — Stadium Conglomerate, or redeposited San Diego Formation. Hard drilling

100 feet — Really hard and slow drilling, scared us again; thought we’d hit bedrock, was just a hard boulder and a worn out bit.

150 feet — Stadium Conglomerate, wore out two bits so far (button carbide and tipped iron).

234 feet — Formational change to sand; obtained cores. Friar’s formation? Seaward facies of Stadium?

280 feet — Still in oxidized (red streaks) of sand with variably clay.

410 feet — Sandy clay, preparing to obtain another core. I lost my Depth to Bedrock pool; thought we’d hit bedrock by 312 feet. Monte’s gravity suggests about 480 feet.

May 16, 2011:

GOOD NEWS
We hit bedrock. We’re through the sediment, and drilling into bedrock (Santiago Peak Volcanics). Hit bedrock below 398 feet though admittedly it is a bit of a blur between zones of weathered bedrock and hard rock. We are down to 578 feet. We’ll take a core Tuesday morning to see what the material actually looks like. Water flowing into the well is limited so we are not finding highly pressurized bedrock, yet, with too much water to readily get rid of.

BAD NEWS
I may never live this depth-to-bedrock-predicted-by-gravity thing down.

DEPTH TO BEDROCK
Seems we found bedrock at roughly the depth predicted by Monte Marshall’s gravity map processed by Carolyn Glockhoff in our office. While I agree that gravity measurements are helpful at defining the general shape of a basin, which why I was eager to use Monte’s work, I’ve never been under the geophysists’ illusion that the gravity measurements are sufficiently precise to predict anything particular, much less depth to bedrock at a particular drill site.

But then when you have no alternatives, gravity makes sense to use; so we did. And it worked.

Wesley R. Danskin
Research Hydrologist
United States Geological Survey (USGS)
California Water Science Center
4165 Spruance Road, Suite 200
San Diego, CA 92101 USA
619-225-6100 office
wdanskin@usgs.gov

 

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