Friday, April 18, 2014
YOLO COUNTY NEWS
99 CENTS

Ask the expert: Davis’ groundwater future is unknown

By
From page A1 | February 07, 2013 | Leave Comment

* Editor’s note: This is the third in a series of “Ask the expert” columns that will appear in the coming days, in advance of the Measure I election, regarding various technical aspects of the city’s water utility and the proposed Woodland-Davis surface water project.

The expert: Graham Fogg, UC Davis professor of hydrogeology. Fogg’s academic interests include groundwater contaminant transport, groundwater basin characterization and management, geologic/geostatistical characterization of subsurface heterogeneity for improved pollutant transport modeling and numerical modeling of groundwater flow and contaminant transport.

The question: How long can Davis survive with the current well water system and have safe, drinkable water? Can you briefly describe the problems that could arise with the city’s drinking water, in terms of supply and quality, if Davis remained on a well-only system, and when those problems might occur?

The answer: Research indicates that downward movement of contaminated groundwater is a long-term and ongoing process and the deeper groundwater quality potentially will continue to degrade in the coming decades even in the unlikely event that anthropogenic contamination at the surface is eliminated.

In other words, the current well water system, which does include a number of aged wells that need to be replaced, is sufficiently vulnerable to ongoing contamination from surrounding land uses that it would be prudent to consider alternative or supplementary sources of water.

One alternative is to construct more wells in the so-called deep aquifer, which is perhaps more protected from surface contamination because of its depth beneath still more clay and silt layers.

Unfortunately, the capacity of the deep aquifer to satisfy city water demand is unknown at this time because there is not yet enough information on the lateral extent of that aquifer and on how and at what rate it is recharged.

Even if such information becomes available, however, concentrating more groundwater pumpage in the deep aquifer will only accelerate the downward movement of contaminated groundwater toward the deep aquifer. In other words, just because the deep aquifer is deep does not mean it is invulnerable to contamination. When I arrived in Davis in 1989, the intermediate depth aquifer zones that Davis has tapped also were considered invulnerable to contamination. Twenty-four years later it is a different story.

How long can Davis survive with the current well water system? Perhaps one to three decades. Can Davis survive significantly longer if it taps into the deep aquifer? Answer: Unknown, and unlikely to be known until substantially more development of the deep aquifer occurs. The costs of different options must be weighed, but one should also weigh the different degrees of uncertainty inherent to these options.

The main problem with staying on wells likely would be significant uncertainty regarding future capacity of the aquifer system to deliver sufficient volumes of water that meet drinking water standards, both with respect to anthropogenic contaminants (e.g., nitrate and salinity from irrigation) and natural contaminants such as selenium and chrome.

Because the amount of water the aquifer can safely yield is unknown, it is also possible that development of that aquifer will lead to overdraft conditions. In the case of groundwater overdraft, the possible detrimental effects are land subsidence, higher energy costs of pumping from deeper static water levels and intrusion of deep saline groundwater that lies below the deep aquifer.

Enterprise staff

LEAVE A COMMENT

Discussion | No comments

The Davis Enterprise does not necessarily condone the comments here, nor does it review every post. Read our full policy

  • Recent Posts

  • Enter your email address to subscribe to this newspaper and receive notifications of new articles by email.

  • .

    News

     
    Chuck Rairdan joins school board race

    By Jeff Hudson | From Page: A1, 3 Comments

    Going green at church, school, everywhere

    By Special to The Enterprise | From Page: A1 | Gallery

     
    Former caretaker convicted of murder, elder abuse

    By Lauren Keene | From Page: A1, 4 Comments | Gallery

    Old friend helps Brad and others find kidneys

    By Dave Jones | From Page: A1, 1 Comment | Gallery

     
    UCD to host Global Health Day event

    By Cory Golden | From Page: A2

    Ukraine insurgents reject call to quit buildings

    By The Associated Press | From Page: A2, 8 Comments

     
    For the record

    By Enterprise staff | From Page: A2

     
    Need a new best friend?

    By Enterprise staff | From Page: A3 | Gallery

    ‘Hitchhiking’ dog looking for new home

    By Lauren Keene | From Page: A3 | Gallery

     
    Event to provide nature scholarship

    By Enterprise staff | From Page: A4

     
    Online K-12 school holds info night

    By Enterprise staff | From Page: A4

     
    Volkssporting Club plans North Davis walks

    By Enterprise staff | From Page: A4

    Schwenger lawn signs available

    By Anne Ternus-Bellamy | From Page: A4

     
    Volunteers needed for Grad Night

    By Enterprise staff | From Page: A4

    Davis grad makes rain collection a business

    By Jason McAlister | From Page: A4 | Gallery

     
    A few spots left on history tour

    By Enterprise staff | From Page: A4

    Chipotle fundraiser boosts Emerson tech upgrade

    By Enterprise staff | From Page: A4

     
    Students have new options on leasing front

    By Enterprise staff | From Page: A5 | Gallery

    Groups join for a day of service

    By Special to The Enterprise | From Page: A7

     
    NAMI backers walk in Sacramento

    By Special to The Enterprise | From Page: A8

     
    Food for the hungry

    By Enterprise staff | From Page: A10, 1 Comment

    .

    Forum

    Dad makes mom look bad

    By Special to The Enterprise | From Page: B5

     
    In search of great ideas

    By Letters to the Editor | From Page: A6, 1 Comment

    Please keep the nursery open

    By Letters to the Editor | From Page: A6

     
    Early help is a great investment

    By Letters to the Editor | From Page: A6

    More tax money? Answer the question

    By Rich Rifkin | From Page: A6, 5 Comments

     
    UCD IS responsible for students

    By Letters to the Editor | From Page: A6, 5 Comments

     
    Tom Meyer cartoon

    By Debbie Davis | From Page: A6

    .

    Sports

    DHS’ Golston goes full-bore on the diamond

    By Thomas Oide | From Page: B1 | Gallery

     
    Devils show more life in loss to Mitty

    By Enterprise staff | From Page: B1

    Sharks double up Kings in Game 1

    By The Associated Press | From Page: B1

     
    Aggies lose a slugfest in opener at Riverside

    By Enterprise staff | From Page: B1

    Fox coming to UCD; Riffle heads to Florida

    By Bruce Gallaudet | From Page: B1

     
    DYSA roundup: Intensity has big week; 10U games dominate schedule

    By Enterprise staff | From Page: B2 | Gallery

    Sports briefs: Aggies set the academic bar high

    By Enterprise staff | From Page: B8 | Gallery

     
    Pro baseball roundup: Susac sends Sacramento to a rare loss

    By The Associated Press | From Page: B8

    .

    Features

    .

    Arts

    ‘Transcendence’: A whole new level of tedium

    By Derrick Bang | From Page: A11 | Gallery

     
    ‘The Bloom’ paves way for Whole Earth Festival

    By Enterprise staff | From Page: A11

    DHS tribute to Tony Fields slated for April 25-26

    By Enterprise staff | From Page: A11

     
    UCD, city team up for Music on the Green

    By Enterprise staff | From Page: A11

    .

    Business

    Ford turns its Focus to domestic market

    By Ali Arsham | From Page: B3 | Gallery

     
    .

    Obituaries

    .

    Comics

    Comics: Friday, April 18, 2014

    By Creator | From Page: A9

     
    .

    Real Estate Review

    Featured Listing

    By Zack Snow | From Page: RER1

    Professional Services Directory

    By Zack Snow | From Page: RER2

    Lyon Real Estate

    By Zack Snow | From Page: RER3

    Acacia at Huntington Square

    By Zack Snow | From Page: RER4

    Jamie Madison

    By Zack Snow | From Page: RER4

    Yolo FCU

    By Zack Snow | From Page: RER4

    Travis Credit Union

    By Zack Snow | From Page: RER5

    Kim Eichorn

    By Zack Snow | From Page: RER6

    Suzanne Kimmel

    By Zack Snow | From Page: RER6

    Lynne Wegner

    By Zack Snow | From Page: RER7

    Kim Merrel Lamb

    By Zack Snow | From Page: RER7

    Patricia Echevarria

    By Zack Snow | From Page: RER8

    Chris Snow

    By Zack Snow | From Page: RER8

    Andrew Dowling

    By Zack Snow | From Page: RER9

    Sheryl Patterson

    By Zack Snow | From Page: RER9

    Don Guthrie

    By Zack Snow | From Page: RER9

    Coldwell Banker

    By Zack Snow | From Page: RER10

    Coldwell Banker

    By Zack Snow | From Page: RER11

    Heather Barnes

    By Zack Snow | From Page: RER12

    Julie Partain & Dick Partain

    By Zack Snow | From Page: RER12

    Malek Baroody

    By Zack Snow | From Page: RER13

    Karen Waggoner

    By Zack Snow | From Page: RER14

    Willowbank Park

    By Zack Snow | From Page: RER14

    Team Traverso

    By Zack Snow | From Page: RER15

    Julie Leonard

    By Zack Snow | From Page: RER15

    Tim Harrison

    By Zack Snow | From Page: RER15

    Tracy Harris

    By Zack Snow | From Page: RER16

    Lori Prizmich

    By Zack Snow | From Page: RER16

    Joe Kaplan

    By Zack Snow | From Page: RER17

    Raul Zamora

    By Zack Snow | From Page: RER17

    Coldwell Banker

    By Zack Snow | From Page: RER18

    Open House Map

    By Zack Snow | From Page: RER19

    F1rst Street Real Estate

    By Zack Snow | From Page: RER20