HomeMy WebLinkAbout2019-07-08; Additional Information on the San Diego County Water Authority Twin Oaks; |Gomez, Paz | Quiram, Vicki|To the members ofthe:
CITY COUNCIL
Date '.-/ P;/~cA V CC ✓
CM __Imo _j_ DCM (3) V
July 8, 2019
Council Memorandum
To: Honorable Mayor Hall and Members of the City Council
From: Paz Gomez, Deputy City Manager, Public Works
{cityof
Carlsbad
Memo ID# 2019079
Vicki Quiram, General Manager, Carlsbad ME icipal Water District
Via: Elaine Lu key, Chief Operations Officer
Re: Additional Information on the San Diego C nty Water Authority Twin Oaks
Water Treatment Plant
This memorandum provides a second update on the release of San Diego County Water
Authority's (Water Authority) public notice regarding a recent malfunction at their Twin Oaks
Water Treatment Plant.
Background
Staff previously submitted a memorandum dated June 17, 2019, to the City Council that
provided an overview of the malfunction at the Twin Oaks Water Treatment Plant, the
subsequent issuance of a Notice of Violation from the State Water Quality Control Board
Division of Drinking Water, and public notification requirements related to the malfunction.
The memorandum is attached for reference (Attachment A).
On June 27, 2019, staff submitted a second memorandum with additional information from the
Water Authority indicating that public notices would be delayed to July 8 or later. The
memorandum is attached for reference (Attachment B).
Discussion
This week, the Water Authority provided staff with copies of State Department of Drinking
Water approved notifications and outreach documents. The following documents are attached
for reference:
o Notification Postcard, which will be mailed to impacted customers on July 8,
2019 (Attachment C)
o Press Release, which will be issued on July 8, 2019 (Attachment D)
o Tier 2 Public Notice, which requires schools, rental property owners or
managers, and business property owners or managers to provide secondary
notification to employees, students, parents, and tenants (Attachment E)
o Frequently Asked Questions (Attachment F).
Public Works Branch
Faraday Center 1635 Faraday Avenue I Carlsbad, CA 92008 I 760-602-2730
Honorable Mayor Hall and Members of the City Council
July 8, 2019
Page 2
Next Steps
The Water Authority will mail notices, issue the press release and launch a link to a page on
.their website on July 8, 2019. A phone number to reach a Water Authority call center will be
included. The Water Authority has assured staff that it is prepared to respond to all public and
media questions. They will assist schools and property managers with secondary notifications
as needed.
On July 8, 2019, the city will add a link on the city's website that will redirect the customer to
the Water Authority's website. City of Carlsbad staff will be ready to respond to customers that
may contact the city or Carlsbad Municipal Water District.
Attachments:
A) Council Memorandum dated June 17, 2019 re: Information on the San Diego County
Water Authority Twin Oaks Water Treatment Plant
B) Council Memorandum dated June 28, 2019 re: Additional Information on the San
Diego County Water Authority Twin Oaks Water Treatment Plant
C) Notification Postcard
D) Press Release
E) Tier 2 Public Notice
F) Frequently Asked Questions
cc: Scott Chadwick, City Manager
Celia Brewer, City Attorney
Laura Rocha, Deputy City Manager, Administrative Services
Amanda Guy, Deputy City Attorney
Kristina Ray, Communications Manager
. To the mernbers of the:
,JI~ COUNCIL
Date~CA ✓cc ✓ _
CM:k'.::._ COO __!LDCM (3) • ✓
June 17, 2019
Council Memorandum
To: Honorable Mayor Hall and Members of the City Council
From: Paz Gomez, Deputy City Manager, Public Works
Attachment A
. {cityof
Carlsbad
Memo ID# 2019014
Vicki Quiram, General Manager, Carlsb~9 , u. nicipal Water District
Via: Elaine Lu key, Chief Operations Officer
Re: Information on the San Diego County ter Authority Twin Oaks Water
Treatment Plant
This memorandum provides information on a recent malfunction at the San Diego County
Water Authority's (Water Authority) Twin Oaks Water Treatment Plant.
Background
Carlsbad Municipal Water District ("CMWD") and multiple other water districts and cities
purchase treated drinking water from the Water Authority. CMWD purchases all'of its water
from the Water Authority. Before the water reaches the CMWD water distribution system, the
Water Authority treats the water at the Twin Oaks plant.
Discussion
On April 21, 2019, the Twin Oaks plant experienced a treatment malfunction that was caused
by a valve failure. For 12 hours; the ozone residuals in the plant fell be.low state-mandated
levels. Ozone is used as a disinfectant in water treatment systems and is part of the treatment
process at the Twin Oaks plant. Overall water quality was not compromised and there was no
public health concern.
The water agencies affected by the Twin Oaks plant malfunction include CMWD, Vallecitos
Water District, Valley Center Municipal Water District, Rincon del Diablo Municipal Water
District, Rainbow Municipal Water District, City of Oceanside, Vista Irrigation District, Ramona
Municipal Water District, Padre Dam Municipal Water Distdct, Otay Water District, Helix Water
District and the City of San Diego.
The malfunction at the Twin Oaks plant resulted in a Notice of Violation ("NOV") to the Water
Authority from the State Water Resources Control Board Division of Drinking Water. Although
this malfunction did not pose a public h.ealth risk, water users are entitled to know what
happened and what measures were taken to correct the problem.
The Water Authority estimates that it will send required notifications to approximately 30o;ooo
people (see attached map showing Carlsbad Municipal Water District and Vallecitos Water
District boundaries). Olivenhain Municipal Water District customers are not affected. The
Public Works Branch
Faraday Center 1635 Faraday Avenue I Carlsbad, CA 92008 I 760-602-2730
Honorable Mayor Hall and Members of the City Council
June 17, 2019
Page 2
notification will take place on or about July 1, 2019. The NOV is attached and can be found at
the following link:
https:ljwww.waterboards.ca.gov/ drinking water /programs/documents/ d dwem/dwp%20enfor
cement%20actions/San%20Diego/2019/05 14. 19C 003 3710042 41.pdf
· in addition, Health and Safety Code Section 1164S0(g) requires a secondary notification. This
law requires that large organizations notify people within their organizations. Specifically,
within 10 days of receiving the notice, schools must notify employees, sttJdents and parents;
residential rental property owners or managers (including nursing home_s and care facilities)
must notify their tenants; and business property owners must notify their employees.
Due to the· multiple safeguards in place within the tr_eatment systems, the Water Authority has
· assured the City of Carlsbad that the water quality from the Twin Oaks plant is safe. Specifically,
the Water Authority has represented that it has tested the water from the Twin Oaks plant and
the tests of the water in the distribution system show that the malfunction did not impact
overall water quality, the water quality meets all state and federal standards, and there were
and are no public health concerns.
Next Steps
The Water Authority is finalizing the information that will be provided to the public. Because of
_ the regulations involved, getting the final notice prepared takes a little more time than other
types of public notices. The Water Authority is coordinating with its member agency boards and
staff on the release of this information to the public and asking that it be released at the same
time the Water Authority notice is ready to distribute, currently planned no later than July 3.
on or about July 1, 2019, the Water Authority will mail notifications to all customers who
potentially received water from the Twin Oaks plant explaining that treatment requirements
were not met on April 21, 2019. All City of Carlsbad water customers served by CMWD and
Vallecitos Water District will receive notices. City of Carlsbad water customers that are served
by Oliven ha in Municipal Water District will not receive notices since they were not affected.
The Water Authority is prepared to take customer calls and has provided a specific phone
number for this purpose. The city's website will be updated to include a link to the Water
Authority's website which will contain additional information beyond that given in the
notification, including, a fact sheet and a questions and answers document.
CMWD and city customer service providers will also be prepared to handle calls that may come
into the city.
The Water Authority plans to issue a press release no later than July 3, 2019. A copy of the
notice and press release will be forwarded to City Council-once these documents ha_ve been
received;
Honorable Mayor Hall and Members of the City Council
June 17, 2019
Page 3
If you get questions from residents regarding this issue after they receive the notices, please
feel free to direct them to the Water Authority's Escondido office at 760-480-1991.
Attachments:
1. Map showing Carlsbad Municipal Water District and Vallecitos Water District boundaries
2. State Water Resources Control Board letter dated June 4, 2019, to the Water Authority
3. Key Points distributed by the Water Authority
cc: Scott Chadwick, City Manager
Celia Brewer, City Attorney
Laura Rocha, Deputy City Manager, Administrative Services
Amanda Guy, Deputy City Attorney
Kristina Ray, Communications Manager
. A
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Water Boards
State Water Resources Control Board
Division of bdriking Water
June 4, 2019
. _System No. 3710042
Ms. Sandra Kerl, Acting General Manager
San Diego County Water Authority
610 W. 5tn Ave.
Escondido, CA 92025
CITATION NO. 05_14_19C_003
N'~-~AAED. 8LUMENFElD l~~ SECRElAAV FOR ~ £Nv!F':or,o,\i:UTAL PROTECTIC►I
· TREATMENT T ECHNIQUE VIOLATION FOR FAILURE TO MEET DISINFECTION
CONTACT TIME FOR APRIL 2019
Enclosed is Citation No. 05_14_19C_003-(hereinafter"Citation"), issued to San Diego
County Water Authority (hereinafter "SDCWA"). Please note that there are legally
enfqrceable deadlines associated with this Citation.
SDCWA will be billed at the State Water Resources C.ontrol Board's (hereinafter "State
Water Board") hourly rate for the time spent on issuing this Citation. California Health
and Safety Code (hereinafter "CHSC"), Section 116571, provides that a public water
system must reimburse the State Water Board for actual costs incurred by the State
Water Board for specified enforcement actions ·including, but not limited to, preparing,
issuing and monitoring compliance with a citation.
SDCWA will receive an enforcement invoice from the State Water Board around August
2019. The invoice will contain fees for any enforcement time spent on SDCWA for the
previous fiscal year.
A public water system may file a petition With the. State _Water Board for reconsideration
of a citation, order or decision made under authority delegated to an officer or employee
of the State Water Board. Petitions must be received by the State Water Board within
30 calendar days of the issuance of the citation, order, or decision._
The date of issuance is the date when the Division mails or serves a copy of the
citation, order.or decision, whichever occurs first. If the 30th day falls on a-Saturday,
Sunday, or state holiday, the petition is due the following business day by 5:00 p.m.
E . JOAQUIN EsaUIVEL, CHAJ.R I EILEEiil SOBECK. EXECUTIVE .DIRECTO~
1350 Fron! Street, Room 20~0.:san Diego, CA 92101 I www.waterboards.ca.gov
CJ A~CYCLEll PAPf H
Ms. Sandra Kerl
June 4, 2019
San Diego County Water Authority
System No. 3710042
Information regarding filing petitions may be found at
http://www.waterboards.ca.gov/d rinking water/programs/petitions/index. shtm I
If you have any questions regarding this matter, please contact Tuba Ertas or me at
(619) 525-4159. . .
Sincerely,
Sean Sterchi, P.E.
District Engineer
Enclosures: Citation No. 05_14_19C_003
· Certified Mail No. 7018 1130 0001 76-17 3091
cc: Lars.Seifert, Chief, San Diego Department of Environmental Health (via e-mail)
Jim Fisher, Director of O & M (via e-mail)
Brian MacDonald, Chief Operator (via e-mail) .
Ashley Dummer, District Engineer, Santa Ana Office (via e-mail)
Impacted Agencies:
Matt Vespi, Interim Pub. Utility Director, City of San Diego (via e-mail)
lsaam Hireish, Deputy Director WS Ops., City of San Diego (via e;..mail)
Glenn Pruim, General Manager, Vallecitos Water District (via e-mail)· ·
Shawn Askine, Water System Supervisor, Vallecitos Water District (via e-mail)
Gary Arant, General Manager, Valley Center Municipal Water District (via e-mail)
Greg Hoyle, Director of Operations, Valley Center MWD (via e-mail)
Clint Baze, Director of Oper., Rincon Del Diablo MWD (ID-A & ID-1) (via e-mail)
Tom Kennedy, General Manager, Rainbow Municipal WD (via e-mail)
Marc. Walker, Water Ops. Superint., Rainbow Municipa WD (via e-mail)
Ronald Lutge, Chief Plant Operator; City of Oceanside (via e-mail)
Frcin_k Wolinski, Operations Manager, Vista Irrigation District (via e-mail)
Eric Sanders, Utility Supervisor Water Operations, Carlsbad MWD {Viel e-mail)
Troy Henry, System Supervisor, Ramona Municipal WO (via e-mail)
Paul Clarke, Director of Operations, Padre Dam MWD (via e-mail)
Mark Watton, General Manager; Otay Water District (via e-mail)
Jake Vaclavek, System Operations Manager, Otay Water District (via e-mail)
Carlos Lugo, General Manager, Helix Water District (via e-mail)
Larry Lyford, Water Treatment Plant Manager, Helix Water District (via e-mail)
Page 2 of 2
2
3
4
5
6
Citation No. 05-14-19C-003
STATE OF CALIFORNIA
STATE WATER RE.SOURCES CONTROL BOARD
DIVISION OF DRINKING WATER
7 Name of Public Water System: San Diego County Water Authority
8 Water System No: 3710042
9
10 Attention: Sandra Kerl, Acting General Manager
11 San Diego County· Water Authority
12 610 W. 5th Ave.
13 Escondido, CA 92025
14
15 Issued: June 4, 201'9
16
17
18
19
20
21
22
23
24
. CITATION FOR NONCOMPLIANCE
CALIFORNIA CODE OF REGULATIONS, TITLE 22
SECTIONS 64652(a), 64654 (a), _ 64661 (a), Section 64463.4(a)(1 )(b)
TREATMENT TECHNIQUE VIOLATION
FOR FAILURE TO MEET DISINFECTION CONTACT TIME
2s The California Health and Safety Code (hereinafter "CHSC"), Section 116650
26 authorizes the State Water Resources Control Board (hereinafter "State Water
21 Board") to issue a citation to. a public water system when the State Water Board
28 determines that the public water system has violated or is violating the California
29 Safe Drinking Water Act (hereinafter "California SOWA"), (CHSC, Division 104,
30 Part 12, Chapter 4, commencing with Section 116270 ), or any regulation,
31 standard, permit, or order issued or adopted thereunder.
Page 1 of 9
Citation No. 05m14-19C~003
1 . The State Water Board, acting by and through its Division of Drinking Water
2 i (hereinafter "Division") and the Deputy Director for the Division, hereby issues
3 · Citation No. 05_ 14_ 19C_003 (hereinafter "Citation") pursuant to Section 116650
4 • of the CHSC to San Diego County Water Authority (hereinafter, "SDCWA"), for
s i ·Violation of the California Code of Regulations (hereinafter, "CCR"), Title 22,
6 J Sections 64652(a). . ·
7 I A copy of the applicable statutes and regulations are incl~ded in Appendix 1,
s which is attached hereto and incorporated by reference.
9 STATEMENT OF FACTS
10 SDCWA is a regional water wholesaler and prese·nt1y provides 75 to 95 percent
11 of the water used in its service area. SDCWA purchases the substantial majority
12 of its water (both untreated and treated) from the Metropolitan Water District of
13 Southern California (MWD), delivering that water to its 24 member agencies
14 through two aqueducts comprised of a total of five north-south pipelines. This
1s network of large transmission lines currently consists of approximately 300 miles
16 of pipeline varying in diameter from 22 to 108 inches. Treated and· u.ntreated
11 water flows by gravity from MWD's Skinner Filtration Plant into San Diego
18 County. SDCWA then delivers the water to its member agencies through 106
19 metered flow control facilities.
20 SDCWA owns one treatment plant: Twin Oaks Valley Water Treatment Plant
21 (TOVWTP) in San Marcos. TOVWTP uses submerged membrane filtration
22 followed by ozonation, biologically activated carbon and chlorination and is rated
23 at 100 MGD. The TOVWTP processes are summarized in the following table.
24 Treatment Proce.ss Summary .
· · Treatment\ . · ·· · · · · · i ·::< ·· · .·. ) P~:S~ripf!(:>i:is ; .· ..
LiliiL•.:. ·
·>,,.
Untreated
Water Gravity
Feed
I 21Page
Untreat!:)d water is gravity fed from the 96'-inch Pipeline 5 to a 78-inch line that
splits into two 42-inch lines upstream of the Untreated Water Flow Control
Facility (UWFCF).
Citation No. 05-14-19C-003
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:':.' "·. ,:·.. .. ·'·.>.':' .. <> ·,:/:'•' .. ,.'· >}~<· .... ·.··..:.·. '"'··· •'
Untreated
Water
Pump Station
Untreated
Water Flow
.Control Facility
The Untreated Water Pump Station (UWPS) draws untreated water from the
Twin Oaks Valley Flow Regulating Structure (TOVFRS) and discharges into a
78-inch line that splits into twb 42-inch lines upstream of the UWFCF. The
UWPS is equipped with four·17,500 gallon per minute (gpm) Weir-Floway
vertical turbine pumps operated in parallel. Each vertical turbine pump is
driven by a constant-speed motor'. ·
The UWf=CF meters and regulates untreated water flows (flow range of 25 -
110 MGD} to the Fine Screening. The UWFCF consist of two equally sized
flow trains connec_ted in parallel. Each flow train has a flow range of 25 -55
MGD and Is capable of operating separately, or in parallel combination. Each
train consists or an upstream isolation ball valve, an ultrasonic flowmeter,
triple offset butterfly valve for flow control, and a butterfly valve for
downstream isolation, Return flow from the Residuals-Handling Facility is
blended W(th the influent stream at this facility. ·
Fine Screening Untreated water passes through three rotating ar.id self-cleaning S.P.Kinney
457-micron screens and then flows to the submerged membrane filtration
facility.
Submerged
Membrane
1 Filtration
3 j p ii g C
Membrane filtration _is provided by a Zenon ZeeWeed 1000 V3 and V4 system
(6 V3 trains and 8 V4 trains, all will be V4 upon completion of the phased V3
train membrane change outs). The V3 modules have a Vsys of 600 ft2 for an
individual cassette volume of 1,479.52 gallons and the V4 modules have a
Vsys of 550 ft2 for an indlvidual cassette volume of 1,313.07 gallons;
Screened, lintr~ated water enters the submerged rnembr'ane filtration (SMF)
facility and is distributed to the membrane trains through a feedwater channel
and feed piping. The feed channel provides a hydraulic break between the
UWFCF and the membrane trains. Feedwater enters the membrane tanks
throwgh a bottom sump with a baffle plate and rises through the tank or
permeates through the membranes. A permeate pump draws the water
througb the membrane fibers under vacuum pressure and discharges the
filtered water permeate into a common 72-inch permeate header that feeds
the ozone contactor facility.
The SMI= facility is comprised of 14 membrane trains (tanks) c1rranged in
parallel. The tanks are grouped into two banks of seven trains. Each
membrane train contains 6 cassettes housing a maximum of96 modules, in a
12-foot wide by 17-foot long tank. The cassettes are suspendecl in the tanks
from stainless steel beams mechanic:aUy attached to the tank walls. Each
train has a dedicated permeate pump, associated piping, and $Upport
systems (backwash system, chemical metering systems, chemical cle;aning
systems, air scour system, membrane integrity testing (MIT) system, and
instrument air system). The CIP chemicals consist of 12% sodium
hypochlorite, 50% citric acid and 40% hydrochloric acid. A vacuum pump
system (1 duty, 1 standby) operates intermittently during system operation to
keep the permeate piping free of entrained air and to prime the permeate
pumps. The SMF also houses the membrane cleaning chemicals: sodium
hypochloritesolution (12 -15%), citric acid, and hydrochloric acid.
The filtration process operates in deposition mode with a return flow from the
Residuals~Handling system.
Ozon~
Contactor
Facility
Biologically
Active
Carbon
Contactors
Citation No. 05a14-19C-003
An 18,000 gallon submerged membrane backpulse tank was added to supply
the backpulse pumps (1 duty, 1 standby) from .this tanks as opposed to _the
permeate header and reduce flow variations to the ozone contactor.
The permeate pumps transferfiltered water to the ozone contact _facility.
Ozone is injected into the process flow in the front end of the ozone contactor
using fine bubble diffusion. The water then flows through the contactors to
provide contact time for Gfardia and virus inactivation. Two distinct sections
9re provided within the ozone contactors. The first section, which consists of
an inlet channel and three cells.configured with over-under baffles, is used for
ozone injec:tion and inactivation contact time; The sec.and section, whic~ is
constructed with five cells using serpentine baffles, provides hydrogen
peroxide injection,· contact time for advanced oxidation, and ozone quenching
through sodium bisulfite' injection.
The ozonated water flows into the Biologically Activl;) Carbon (BAC) co11tactor
and is.distributed to the BAC beds. The BAC system is comprised of10
basins arranged in parallel. The BAC beds are grouped into two banks 0ffive
basins. Each bed has 6 feet of activated carbon media and is 24 feet wide by
32 feet long. The beds are similar in design to conventional deep granular
media filters. Each bed has a maximum hydraulic loading rate (HLR) of
approximately 10 gallons per minute per square foot (gpn,/ft2) and has been
designed for a nominal empty bed contact time (EBCT) of 5 minutes. Each
bed is monitored for level, flow, headloss, and runtime. These values are
used to monitor contactor oerformance and initiate backwash cvcles.
l'i=. =======+=========================='=================================.r....=======il The chemical mix chamber (CMC) is located immediately downstream of the
I !
i
Chemical
Mixing
Cliamber
Clearwells
Treated Water
Flow Control
Facility
Residuals-
Handling
System
l41Pnge
BAG f;:icility. The CMC is a concrete water-holding basin with two Weir-
Floway vertical turbine pumps to promote mixing and serpentine baffles to
provide detention time for chemical reactions. Chlorine and ammonia are
added at a specific ratio to form chloramines for matching the existing
residual disinfectant within Pipeline 4. Sodium hydroxide can be added as
necessary to increase the pH of the water in order to reduce corrosivity ;:ind
help stabilize the chloramine residual. Fluoride can be added to the flow as
necessary to meet target fluoride levels. A venturi meter is installed
immediately downstream ofthe CMG basin to monitor treated water flqw from
the treatment plant.
Following the CMG, treated water will flow into two circular prestressed
concrete clearwells. Each clearwell has a capacity of 7 .5 MG. The clearwells
are hydraulically connected to operate at the same water level and are 1..1n-
baffled. The primary control of the water surface in the clearwells is the flow
control valves in the Treated Water Flow Control Facility (TWFCF). The
clearwells have been modified with connections and piping to allow ·
desalinated seawater to mix with the TOVWTP treated surface water prior to
distribution to the iWFCF.
The TWFCF monitors and controls treated water from the TOVWTP
clearwells to Pipeline 4, corresponding to distribution system demand rates of
25 to 17 4 MGD. The TWFCF consists of one 42-inch diameter and one 54-
inch diameter train operating in pa~aliel. Each train consists of an upstream
isolation ball valve, an ultrasonic flowmeter, a butterfly valve for flow control,
and a butterfly valve for downstream isolation. Each flow train is capable of
operatinq separatelv or in parallel. ·
The Residuals-Handling system receives waste washwater generated by the
various sources in the water treatment process, provides solids/liquid
separation, and returns the treated waste washwater back to the UWFCF.
The Residuals-Handling system consists of the following facilities:
Equalization Basins, Clarifiers, Gravity Thickeners; and Centrifuges. The
I
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3
4
5
6
7
8
9
10
11
12
n
14
15
16
17
18
19
20
21
22
23
Chemical
Facility A
Chemical
Facility B
Chloramine
Boost Facilities
Citation No. 05-14-19C-003·
··.-• .. ·
>·· . :': .. ~--' -; :·
•' .:· .:, ,,•:,•, ,' ,. · .. •,·,,f''·: ,.;,: ·,<.,,, ' .. · ' '"
polymer storage and feed systems used for the Residuals-Handling System
are housed in the dewaterino buildino.
Chemical Facility A receives, stores, and provides flu6tosilicic add, aqueous
ammonia, ferric chloride, hydrogen peroxide, sodium bisulfite, and sodium
hydroxide to TOVWTP chemical injection sites.
Chemical Facility B provides the primary storage, generation, and distribution
of the 0.8~percent (as chlorine} sodium hypochlorite solution used at the .
TOVWTP,
The Chlorami.lie Boost Facilities provide for the mixing·and injection of s_odium
hypochlorite and aqueous ammonia to desalinated water or to combined
Clearwell effh-1ent for the purpose of boosting chloramine residual. Facilities
also include water auality monitoring.
TOVWTP is fully automated with automatic shutdowns based on a series of
water quality parameters identified in the Operations Plan. Operators alerted of
aJarm conditions can view conditions and trends, and take appropriate actions
remotely through the plant SCADA system.
The Zenon ZeeWeed 1000 V4 series membranes were granted conditional log
removal credit(LRC) for 4-log Cryptosporidium, 4-log Giardia, and 3.5-log virus
· removal via the Division's Alternative Filtration Technology (AFT) demonstration
process. The demonstration was performed with a maximum recovery of 95
percent, a maximum TMP of 12 psig, a maximum flux of 55 gfd, and membrane
. integrity demonstrated by daily pressure decay test (PDT). The. TOVWTP
operates in deposition mode with a recovery rate goal of less than or equal to 97
percent, a maximum instantaneous flux of 42 gfd, a maximum TMP of 13 psig,
and will perform daily PDT for direct integrity testing.
In order to gain approval to operate with a lower LRC or 3-log Giardia and
Cryptosporidium, GE/Zenon performed additional demonstration studies on the
ZeeWeed 1000 V3 & V4 membranes that verified a minimum of 3-log
Cryptosporidium and Giardia and minimum of 2-log virus reduction could be
achieved provided the level of care of the membranes resulted in a calculated
LRV of 3.2 log or greater. Additionally, the TOVWTP primary disinfection system
is operated to meet a minimum of 0.5-log Giardia and 2-log virus inactivation to
provide multi barrier treatment and achieve the minimum virus inactivation ·
requirements. Consequently, TOVWTP must be operated with a i.JCL of no less
Citation No. 05a14-19C-003
than 3.2 to ensure Giardia multi-barrier and overall virus reduction requirements
2 of the surface water treatment rule are met.
3 The ozone system has been sized to provide the required ozone capacity for
4 inactivation of 0.5-log Giardia and 2-l~g virus at all times, as well as taste and
s odor control when needed for a flow rate of 100 MGD. The Ozone Contactor
6 Facility consists of two parallel trains, including two Liquid Oxygen (LOX)
7 storage tanks, two vaporizers; two ozone generators, and a 2-train contactor.
8 / Each ozone generator has a maximum production capacity of 1,800 lb/day, but if
9 , both generators are required to be in operation at the same time, a maximum of
10 2,400 lb/day is deliverable through the ozone piping. The two 15,000-gallon LOX
11 storage tanks and the two vaporizers are located on a pad adjacent to the ozone
12 contactor. The LOX storage is sufficient for 30 days at average daily demand.
13 CCR, Title 22 Section 64652 {a) requires that a supplier using an approved
14 surface water shall provide multibarrier treqtment that meets the requirements of
1s Chapter 17 ;:1nd reliably ensures at least, between a point where the raw water is
16 not subject to recontamination by surface water runoff and a point downstream
17 before or at the first customer:
18 (1) A total of 99.9 percent reduction of Giardia lamblia cysts through fil_tration and
19 disinfection;
20 (2) A total of 99.99 percent reduction of viruses through filtration and
21 disinfection; and
22 (3) A total of 99 percent removal of Cryptosporidium through filtration.
23 CCR, Title 22, Section 64654 (a) requires that all approved surface water utilized
24 by a supplier shall be provided -with continuous disinfection treatment sufficient
2s to insure that the total treatment process provides inactivation of Giardia lamblia
26 cysts and viruses, in conjunction with the removals obtained through filtration, to
27 meet the reduction requirements specified in section 64652(a).
2s CCR, Title 22, Section 64661 (a) requires that a supplier shall operate each
29 treatment plant in accordance with an operations plan that has been approved
30 by the State Board.
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Citation No. 05-14-19C-003
CCR, Title 22 Section 64463.4( a)( 1 )(b) requires a water system to give public
2 notice pursuant to this section if any of the following occurs:
3 (1 J Any violatiOn of the MCL, MRDL, and t~eatment technique requirements.
4 On April 21, 2019: A second ozone contactor was placed into operation at &.30
5 pm due to an increase in water treatment demand from 54-MGD to 68-MGD ..
6 Prior to the flow increase, only one ozone contactor was in operation. The
7 influent valve to the second contactor failed to fully open and as a result the
8 majority of the flow was sent to only one contactor.
9 The incident was discovered at 12.50 pm on April 22, 2019 and measures were
10 taken to correct the plant's operations .. During the incident, th·e total plant flow
11 was as high as 75 MGD, with only 8 to 1 O MGD going to the second contactor,
12 and the lowest calculated inactivation for the first contactor was 0.17-Log Giardia
13 and 1.35:-Log virus. The minimum inactivation requirements for the ozone
14 system are 0.5-log Giardia and 2-log virus.
15 On April 22, 2019: The Division was contacted by treatment plant staff and had a
16 conference call meeting with the chief operator and SDCWA. The Division
17 considered the membrane filtration removal credits of 3-log Giardia and 2-log
18 . virus, and calculated CT for other segments of the treatment plant; including. raw
19 water free chlorine disinfection; Chemical Mix Ghamberfree chlorine
20 . disinfection, and downstream total chloramine disinfection. The Division
21 determined that the overall minimum pathogen reducti.on requirements of the
22 Surface Water Tre.atment Rule were likely met; therefore, a Tier 1 Public
23 Notification was not warranted for the April 21/22, 2019 Treatment Technique
24 . · violation.
25 On April 25, 2019: The chief operator submitted an incident report (in Appendix
26 2) along with procedures to prevent reoccurrence of this failure to the Division.
21 On April 30, 2019: The chief operator provided additional water treatment plant
28 programming actions (hereinafter' PLC upgrades) to be taken to prevent a similar
29 incident.via email. An excerpt of that email is copied below:
Citation No. 05-14-19C-003
1 /. Creating and normalizing the ratio.
2 1. The target ratio will be ozone ga_s flow which is fed toward one contactor
3 divided by resid_ual ozone ccmcentration at location C1 or C-€nd at same
4 l contactor; Units are [SCFM]l[mg/L].
s 2. Maximum ozone gas flow can be 300 SCFM. To convert in %, SDCWA will
6 mu/Uply measured value by [100/300].
1 3. Maximum ozone concentration at location C1 can be 3.0 mg/L. To convert in
s · % SDCWA will multiply measured value by [100/3].
9 4. After conversion the ratio [Ozone Gas Flow]/[Ozone Cone] in one contactor
10 will be in units of[%]/[%] or unitless ..
11 //. Creating alarm
12 1. Take ratio from Contactor 1 and divide by same ratio from Contactor 2.
13 2. When both Contactors are running, if the result is in the range 0.8-1.2 mg//,.,
14 SDCWA will have acceptable conditions for disinfection.
15 3. When both Contactors are running, and result is outside the range 0.8-1.2
16 mg/L, SDCWA will create alarm.
11 Ill. Corrective actions
1 s 1. Check position of inlet ancf outlet gates for both contactors.
19 2. Check position of manual isolation valves for ozone flow toward all diffuser
20 headers. Ensure equal position between both contactors.
21 3. Check last calibration date for ozone sensors at location C1 for both
22 contactors. Consider re-calibration.
23
24
s Ir a g"'
Citation No. 05-14-19C-003
DETERMINATIONS
2 Based on the above Statement of Facts, the Division has determined thatSDCWA
3 is in violation of CCR, Title 22, Sections 64654 (a); 64652 (a), 64463.4 (a)(1 )(b)
4 and 64661.
s SDCWA is in violation of CCR, Title 22 Section 64652 (a), in that the water system
6 has failed to provide multibarriertreatment that meets the requirements of Chapter
7 17.
s SDCWA is in violation of CCR, Title 22 Section 64654 (a), in that the water system
9 / has failed to provide continuous disinfection treatment sufficient to insure that the
10 1 total treatment process provided inactivation of Giardia and viruses, in conjunction
11 with the removals. obtained through filtration, to meet the reduction requirements
12 specified in section 64652(a) at the compliance points for the plant.
13 SDCWA is in violation of CCR, Title 22 Section 64661, in thatthe water system
14 has failed to operate the treatment plant in accordance with the operations plan
15 that has been approved by the State Water Board and also failed to comply with
16 , permit provision #16 of Permit No. 05-14-15P~009, issued on October 9, 2015.
17 DIRECTIVES
18 SDCWA is hereby directed to take the following actions:
19 1. Within 60 days of the date of this citation, SDCWA must submit to the Division
20 a revised Operations Plan that includes system and operational procedure
21 upgrades that will ensure a similar incident as described in this citation will not
22 occur again. The revised Operations Pla.n must include the PLC upgrades for
23 the implementation of a CT ratio parameter proposed by the chief operator and
24 . summarized in the Statement of Facts above.
25 2. Within 30 days of issuance of this Citation, SDCWA must implement the PLC
26 upgrades as summarized in the Statement of Facts section above.
27 3. Within 30 days of issuance of this Citation, SDCWA must give public
2s notification of the Treatment Technique violation to all customers who received
29 or may have received water produced by TOVWTP from April 21, 2019 at 8:30
J 9 Ir a g i::
Cit~tion No. 05-14-19C-003
1 1: pm to April 22, 2019 at 12:50 PM in accordance with CCR, Title 22, Section
F -.
2 I/ 64463.4 and the Spanish language public notification requirements of CGR, Title
3 22 Section 64465(c)(2). Public notice must be via, as a miliimurrt one of the
4 _ following forms:
5 , (A) Mail or direct delivery to each customer receiving a bill, including tnose that
6 , provide their drinking water to others (e.g., schools o~ school systems,
7 apartment building owners, or large private employers), and other service
8 connections to which water is delivered by the water system; and
9 (B) Use of one or more of the following methods to reach persons not likely to be
r --
10 I reached by a mailing or direct delivery (renters, university students, nursing
11 home patients, prison inmates, etc.):
12 1. Publication in a local newspaper;
,I
13 ii The required public notification may be done by SDCWA or a combined effort of
14 1 the SDCWA and effected member agencies. A public notification plan and draft
15 ! notification(s) must be submitted to the Division for review anc! approval prior to
16 I conducting public notification. -
11 14• In accordance with CCR, Title 22, Section 64469 (d), within 10 days of
18 1/ conducting public notification, SDCWA must provide to the Division certification
19 of public notification using the enclosed form (Appendix 3).
20 5. SDCWA must complete and return to the State Water Board the "Notification
21 --of Receipt" form (Appendix 4) within 7 days of issuance of this Citation.
22 , Completion of this form confirms that SDCWA has received this Citation and
23 I understands that ii contains legally enforceable directive(s) with due dates.
24 J 6. By July 1, 2020, SDCWA and effected member agencies must report the l . .
2s l Treatment Technique violation in the SDCWA's and each effected member
i . .
_26 agencies' 2019 Consumer Confidence Report (CCR). Draft CC R's must receive
21 _ -written Division approval prior to distribution. ! . .
28
29
l
l lOjPage
Citation No. 05-14-19C-003
All submittals required by this Citation must be electronically submitted to the
2 Divisjon at the following address. The subject line for all electronic submittals
3 corresponding to this Citation must include the following information: San Diego
4 County Water Authority, 92025, Citation No. 05-14-19C-003 and title of the
5 document being submitted.
6 Sean Sterchi
7 DDWSanDiego@Waterboards.ca.gov
8 The State Board reserves the right to make such_ modifications to this Citation as
9 it may deem necessary to protect public health and safety. Such modifications ·
10 may be issued as amendments to this Citation and must be effective upon
11 issuance.
12 Nothing in this Citation relieves SDCWA of its obligation to meet the.
13 requirements of the California SOWA (CHSC, Division 104, Part 12, Chapter 4,
14 commencing with Section 116270), or any regulation, standard, permit or order
15 issued or adopted thereunder.
16 PARTIES BOUND
11 This Citation must apply to a.nd be binding upon SDCW A, its owners,
18 shareholders, officers, directors, agents, employees, contractors, successors,
19 and assignees~
20 SEVERABILITY
21 , The requirements of this Citation are severable~ and SDCWA must comply with
22 each and every provision thereof notwithstanding the effeGtiveness of any
-2; pro_,,_,vi"-'$ ..... iDeu-□s..,__ ____________ ~
24 FURTHER ENFORCEMENT ACTION
25 I The California SOWA authorizes the State Water Board to: issue a citation or
26 order with assessment of administrative penalties to a public water system for
21 . violation or continued violation of the requirements of the California SOWA or
28 any regulation, permit, standard, citation, or order issued or adopted thereunder
111 p il g ~
Citation No. 05-14-19C-003
including, bqt not limited to, failure to correct a Violation identified in a citation or
2 compliance order. The California SDWA also authorizes the State.Water Board
3 , to take action to suspend or revoke a permit that has been issued to a public
4 I water system if the public water system has violated applicable law or
5 I: regulations or has failed to comply with an order of the State Water Board, and
6 I to petition the superior court to take various enforcement measures against a
7 public water system that has failed to comply with an order of the State Water
8 Board. The State Water Board does not waive any further enforcement action by
9 issuance of this Citation.
10 ! ./J !j_ . 6 Jy 1, ~
11 I Sean Sterchi, P.E. Date
12 District Engineer
.13 San Diego District
14 State Water Resources Control Board -Division of Drinking Water
15
16
17 cc: Lars Seifert, Chief, San Diego Department of Environmental Health
18 (via e-mail)
19
20 APPENDICES: ·
21 1) Applicable Statutes and Regulations
22 2) Incident Report ·
23 3) Proof of Notification
24 4) Notification of Receipt
25
26
27 CERTIFIED MAIL NO. 7018 1130 0001 7617 .3091
28
121P.ng~
APPENDIX 1. APPLICABLE STATUTES AND.REGULATIONS FOR
CITATION NO. 05-14-19C-003
NOTE: The following language is provided for the convenience of the recipient, and cannot
·be relied upon as lhe· State of California's representation of the law. The published codes
are the only official representation of the la.w. Regulations related to.drinking water are ih
Titles 22 and 11-of the Califor_nia Code of Regulations. Statutes related to drinking water .
are in the. Health & Safety Code, the Water· Coder and other codes.
California Health and Safety Code (CHSC):
§Sectio·n 116271 states in relev~nt part:
(a) The State Water Resources Control Board s.ucc_eeds to and is .vested wRh all of the
authority, duties, ·powers, purpose~, functions, responsibilities, and jurisdiction of the
s·tate Department of Public Health, its predecessors, and its directorJor-purposes of all of
the foliowing:· . · ·
·(1) the Environmental Laboratory Accreditation A.ct (Article 3 (commencing with Section
100825) of Chapter 4 of Part 1 of Division 101 ). . ·
. (2) Article 3 (commencing with Section 106875) of Ch~pter4 of Part 1.
(3) Article 1 (commencing with Section 115825) of. Chapter ·s of Part 1 o.
(4) This chapter and the Safe. Drinking Water State Revolvi'ng Fund Law of 1997 (Chapter
4.5 (commencing with-Section 116760)). .
(5) Article 2 .(commencing with Section 116800), Article 3 ( commencing with Section
. 116825), and Article 4 ( commencing with Section 116875) of Chapter 5.
(6) Chapter 7 (commencing with Secti_on 116975). · ·
(7) The Safe Drinking Water, Water Quality and Supply, Flood Control, .River and. Coastal
Protection Bond Act of 2006 (Division 43 ( commencing with Section 75001) of the Public
Resources Code.). · · ,,
(8) The Water Recycling. Law (Chapter 7 ( commencing_ with Section 13500) of Division 7
of the Water Code). · · · · ·
(9) Chapter 7.3 (commencing with Section 13560) of Division 7 of the Water Code.
(10.) The California Safe Drinking·Water Bond Law of 1976 (Chapt~r 10.5 ( commencing
with Section 13850) of Division 1 of the Water Code). _
(11) Wholesale Regional Water System Security and Reliability Act (Division 20.5
(commencing with Section 73500)-of the Water Code).
(12) Water Security, Clean Drinking Water, Coastal and Beach Protection Act of 2002
(Division 26.5 (commencing with Section 79500) of_the Water Code). · ·
(b) The State Water Resources Control Board shall maintain a drinking water program
and carry out the duties, responsibilities;and functions described in this section. Statutory
reference to "department," "state department," or "director" regarding a functio"n
transferred to the State Water Resources Control Board shall refer to the State Water.
Resources Control Board. This section does not impair the authority of a ·tocal health
officer to enforce this c~apter or a county's election not to enforce this chapter, as ·
provided In Section 116500. _
(k)(1) The State Water R~sources Contra'! Board shall appoint a deputy director who
'reports to the executive director to oversee the issuance and enforcement of public water
· system permits and other duties· as appropriate. The deputy dir~ctor shall'have public
health expertise. · · ·
I I I -I .
!
Citation No. 05-14-19C~003
(2) The deputy director is deiega,ted the State Water Resources Control Board's -authority
to provid~ notice, approve notice content, approve emergency hotification plans, and take
other action pursuant to Article 5-( commencing with Section 116450), to issue, renew,
reissue, revise, -amend, or deny any public water system permits pursuant to Article 7
( commencing with Section 11652-5), to suspend or revoke any public water system permit
pursuant to Article 8 ( commencing with Section ·116625), and to issue citations, assess
penalties, or issue orders pursuant to Article 9 ( qommencing with Section 116650).
Decisions arid actions of the deputy director taken pursuant to Article 5 ( commencing with .
Section 116450) or Article 7 (commencing with Section 116525) are deemed decisions
and actions taken, but are not subjectto reconsideration, by the State Water Resources
· Control Board. Decisions and actions of the deputy director taken pursuant to Article 8 .
(comh1encing with Section 116625) and·Articl~ 9 (commencing with s·ection 116650) are
. deem_ed decisions and ·actions tal<en by the State Water Resources Control Board, but
any aggrieved person may-petition the. State Water Resources Contro·I Board.for
reconsid~ratio11 of the decision or action. This subdivision is not a limitation on the State
Water Resnurces Control Board's authority to delegate any other powers and duties.
§Section 116650 states in relevant part:. .
(a) If the State Water Board determines that a public w~ter system is in violation of this
chapter or any regulation, permit, standard, citation, or order issued or adopted
thereunder, the State Water Board may issue a-citation to the ptJblic water·system. The
citation shall be served upon the public water system personally or by certified mail.
Service shall be deemed effective as of the date of personal service or the date of receipt
of the certified mail. If a person to whom a citation is directed refuses to·accept delivery of
the certified .mail, the date of service shall be deemed to be the date of mailing. ,
(b} Each citation shall be in writing and shall describe the nature of the violation or
violations, inqluding a reference-to the statutory provision, standard , order1 citation,
permit, or regu·lation alleged to have beeri violated. . · ·
(c) A citation may spe~ify a date for elimination or correction of the condition constituting
the violation. · ·
· (d) A cftation may include the assessment of a penalty as spec1fied in sub~ivision (e).
(e) The State Water Board may assess a penalty in an amount not to_ exceed one .
thousand dollars ($1,000) p.er day for each day that a violation occurred, and for each day
tliat a viola_tion continues to occur.A separate penalty may be assessed ·for each violation
and shall be in addition to any liability or penalty imposed under any other law.
2jPage
. .
Citation No. 05-14-19C-003
§64652. Treatment Technique Requirements and Compliance Options.
· (a) A supplier using an approved surface water shall provide multibarrier treatment that
·meets the requirements of this chapter and reliably ensures at least, between a point . ·
where thEf raw water is not subject to recontamination by•surface water runoff and a point
downstream before or at the .first C\,lstomer: · . _ ·
·(1) A total of 99.9 percent reductiqn of Giardia lamblia cysts throug_h_filtration ahd
disinfection;. · ·
(2) A total of 99.99 percent reduction of viruses through filtration and disinfection; and
(3) A total of 99 percent removal of Cryptospor4di_um through filtration. ·
§64654. Disinfection. · .
(a) All approved -surface water utilized by a supplier shall .be provided with continuous
disinfection treatment sufficient to insure ·. that the total _treatment · process provides
inactivation of Giardia lainblia cysts and viruses, in conjunction witli the removals obtained
through filtration, to meet the.redi.Jcti.on requirements specified in section 64652(a).
§64661. Operations· Plan. . . .
(a) A supplier shall operate each treatm~nt plant in ·accordance with an operations plan
that has been approved by the State Water Board. With a permit appli.catiqn for a new
· . treatment plant or modification to an existing treatment plant, the supplier shall submit for
St;:3te Water Board review the operations plan to determine if it includes those items
required in subsection (b ). The State Water Board shall review .the operations plan to :
determine if it includes those items required In $Ubsection (b ). The operations plan shall
·b_e designed to produce the optimal water quality from the treatment process. The
supplier shall operate its treatment plant in accqrd-ance with the approved. plan. .
(b) The operations plan shall consist of a desctiption of the utility's treatment pl.ant . ·
performance monitoring program, unit process equipment maintenance program, filter
. media inspection ·program, operating personnel, including numbers of staff, certification
levels and .respor:,sibilities; how and when each unit process :i$ operated; laboratory
·. procedures; procedures· used to determine chemical dose rates; records; response to
pla_nt and watershed emergen_cies; and ~eliability features .
.. . .
3IPage
Citation No. 05-14-19q-003
§64463.4. Tier 2 Public Notice.
(a) A water system shall give public notic;:e pursuant to thi.s section if any of the
following occurs: ·
(1) Any violation of the MCL, MRDL, and treatment technique requirements, except:
. (A) Where a Tier 1 public notice is required under section 64463.1: or
(B) Where the State Board determines that a Tier 1 public notice is required, based on
potential health impacts and persistence of the violations;
(b) A water system shall give the notice as soon as possible within 30 days after it learns
of a violation or occurrence speciffed· in subsection (a),· except that the water system may
request an extension of up to. 60 days for providing the notice. This extension would be
subject to the State Board's written approval based on the violation or occurrence having_ .
been resolved and the State Board's determination th~t public;healtti and welfare would
in no way be adversely affected. In addition, the water system shall:
(1) Maintain posted notices in place for-as long as the violation or occurrence ·.
,continues, but in no case less than seven days;
· (2) Repeat the notice every three months· as long a·s the violation or occurrence
continues. Subje_ct to the State Board's written approval based on its determination
tha_t public health would in no way: be adversely affected, the water system may be
allowed to notice less frequently but in no case less than once per year, No
allowance for reduced frequency of notice shall. be given in the case . of a total .
coliform MCL violation or v,iolation of a Chapter 17 treatment technique
requirement; and · .
· (3) For turbidity violations pursuant fo sections 6465'2.5(c)(2) and 64653(c), (d)
and (f); as applicable1 a water system shall consult with the State·soard as soon.
as possible within 24 hours after the water system learns· of the violation to
determine whether a Tier 1 -public notice is required. If consultation do·es not take
piace within 24 hours, the water system shall give Tier r public notice within 48 ·
hours after learning of the violation, ·
(c) A water system shalf deliver the notice, in a manner designed to reach·
persons served, within the required time perioq as follows:
(1) Unless otherwise directed by the State Board in writing based• on its
assessment of the· violation or ocqurrence and the potential for adverse effects on
public health and welfare,.community Wq.ter systems shall give public notice by;
· (A) Mail or drrect delivery to each customer receiving a bill including those that •
provide their drinking water to others (e.g.; schools or school systems, apartment
building owners, or large private employers), and other service connections to
which water is delivered by the water system; and
(B) Use of one or more of the foJlowing methods to reach persons not likely to be
reached by a mailing or direct delivery (renters, university students, nursing home
patients, ~rison inmates, et~:):
1. Publication iii a local newspaper; . . .
2; Posting in conspicuous public places served by the watersystem, ~ron the lnfernet; or
3. Delivery to community organizations;
4jPage
Citation No. 05-14-19C-003
. (2)Unless otherwise directed by the State Board in _writing based on its assessment of
the violation or occurrence and the potential for adverse effects on public health and ·
welfare, noncommunity water systems shall give the public notice by: ·
(A) Posting in conspicuous locations throughout the area served by the wat~r system;
and · . ·
(B) Using one or more of the following methods to reach persons not likely to be reached
by a public posting: .
1 .. Publication in a lo.c.ai newspape_r or newslett.er distributed to customers;
2. E-mail message to employees or.students;
;3. Posting on the Internet or intranet; or
. 4. Direct delivery to each customer. ·
§64465. Public Notice Cont~nt and·Format. -. .
(a) Eat::h public notice given pursuant to this article, except Tier 3 publi~notices for.
variances and exemptions pursuant to subsection· (b), shall contain the following:
(1) A description of the vloli:!tion or occurrence, including the. contaminant(s) of con·cern,
and (as applicable) th~ contaminant level(s); ·
(2) Th~ date(s) of the violation or occurrence;
(3) Any potential adverse health effects from the violation or occurrence, including the
appropriate standard health effects language from appendices 64465-A through G;
· (4) The population at risk, including subpopulations particularly'.vulnerable. if exposed to ·
the contaminant in .drinking water;
(5) Whether alternative water supplies should be -used;.
(6) What aptions consumers should take, including when ·they should seel< medical he.Ip,
if ·known;· ·
(7) What the water system is doing to correct the violation or occurrence;
(8) When th.e water system expects to return to compliance orresolve the occurrence;·
(9) The name, business address, and phone number of the water system owner,
. operator, or designee of the water system as a source of additional° information
cobcerning the public notice;_ · ·
(10) A statement to encourage the public notice recipientto· distribute the public notice to
other persons served, using the following standard language: "Pl.ease share thi~
information with all the other people who drink this water,· especially those who may not •
have received this public notice directly (for example, people.in apartments, nursing·
homes, schools, and business.es). You cari do this by posting this public notice in a public
. place or distributing copies by hand or mail."; and .
. (11) For a 1/\'.ater system with a monitoring and testing .procedure violation, this language
shall be included: "We are required to. monitor your drinking water for specific
contaminants on a regular basis. Results of regular monitoring are an indicator of whether
or-not your drinking water meets health standards. During [compliance period-dates], we
['did not monitor or test' or 'did not complete all monitoring or testing1 for [contaminant( s)J,
and therefore, cannot be sure of the quality of your drinking water during that time." ·
(b) ·A Tier 3 public notice for a water·.system operating under a variance or exemption
shall include the elements in this subsection. ·1f a water system has violated its variance ·.or
exemption cond_itions, the public notice shall .also include the elements in subsection (a).
· (1) An explanation of the reasons for the variance or exemption;
(2) The date on which the variance or exemption was issued;
Sf Page
Citation No.' 05-14-19C-003 ·
(3) A brief status report on the steps the water system is tal<ing to install treatment, find
alternative sources of water, or otherwise comply With the terms and schedules of the
variance or exemption; and · · · ·
(4) A notice of any oppo·rtunity for public input in the review of the variance or exemption.·
( c) A public water system providing n9tice pursuant to_ this article shall comply with the
following multilingual-related requirements:
. _ ( 1) For a Tier 1 public notice: ·
(A) The notice shall be provided in English, Spanish, and the language spoken by any
non-English-speaking group exceeding. 10. percent of the p~rsons served by the public .
· water system, and the notice shall include a telephone number or address where such
individuals may contact the pul;>lic water system for assistance; and _
{B) If any rion-English-speaking group exceeds 1,000 persons served by the public water
· system, but does not exceed 10 percent served, the_ notice shall include information in the ·
appropriate language.(s) regarding the importance of the notice, and the telephone ·
number or address where such individuals may contact the public water system to obtain
a translated copy of the notice from the poblic water system or assistance in the ·
appropriate language;
(2) For a Tier 2 or Tier 3 public notice: .
(A) The notice shall contain information in Spanish regarding· the importance of the notice,
or contain a telephone number or address where Spanish-speaking residents may -
contact the public water system to obtain a-translated copy of the notice or assistance in ·
Spanish; arid .
(B) When a non-English speaking·group other than Spanish-speaking exceeds 1,000
residents or 1 O percent of t~e residents -served by the public water system, the notice
shall include: · ·
1. Information in the appropriate lai:,guage(s) regarding the importance of the notice; or
2. A tefephone number or address where such residents may contact the public water
system tq obtain a translated copy oMhe notl.ce or assistance in t~e appropriate
language; and . .
(3) For a public water system subject to the. Oymally-Alaforre Bilingual Services Act,
Chapter 17.5, Division 7, of the Government Code (commencing with section 7290),
meeting the requirements of this Article may not ensure compliance with.the Dymally-
Alatorre Bilingual Services Act. ·
(d) Each public notic.e given pursuant to this article shall:
· (1). Be displayed such that it catches people's attention when printed or posted-and be
formatted in such a way that the message in the public notice can be understood at 'the
eighth-grade level; ·
(2) Not contain technical language beyond an eighth-grade level or print smaller than 12
point;-a_nd .
(3) Not contain language that minimizes or contradicts the information -being given in the
public notice. · ·
· §64469. Reporting Requirements.
( c)Within 1:0 days of giving initial or repeat public notice pursuant to Article 18. of this
Chapter, except for notice given·under section 64463. 7(d), each water system shall
submit a certification to the State Board that it has done so, along with a representative
copy of_ each. type of public notice given. ·
-
6jPage
Citation No. 05-14-19C-003
.APPENDIX2
. INCIDENT REPORT
· '7 1P ag e
April 25, 2019 ·
Mr. Sean Sterchl, P-.E.
District Ehgjneer ·
Twin Oaks Valley Water Treatment Plant .
3566 lfoih T 1:-r. ().;.k:<; V;:dey l>,,a-.1
s~ri I.JkH~(Jf._ (~A ~~~;1;;~;
Tei 760--?t:l~ ?3:i;
California State Water Resources Contrql Board-Division Drinking Water
San Diego Distr1ct ·
1350 Front Street, Room '2050 ·
San Diego, CA 92101_
I Subject: San_Dlego CountyWater Authority, PWSID# CA3710042
Twin Oaks Valley Water Treatment Plant
Incident Report-Less Than Required Ozo.natlon Inactivation .
Mr. Ste-rchi,
This correspondence serves as a follow-up 1ncident report fotthe events of April 21, 201'9, during which at
~pproxlma!ely =8:30 p.m. a second ozone contactor was placed into operation due to an i_ncrease in water
treatment demand fr-om 54-MGD -to 68-MGD. Typically, normal pr.otocq_l entails placing the second ozone
contactor Into: service whenever the treated flow demand is > 56-MGD.
. .
The following -are the required steps included ln standard Operating Procedure (SOP) for this proce~s:
• Divert all treated water flow from the clearwells to the SDCWA Raw Water Twin Oaks Valley Flow
Regulating Structure (TOVFRS) by placing all Bii;,lo_gically Active Carbon Contactors (BACC's)-offline
resulting in an overflow of entire flow to TOVFRS. . .
• Open the off-line ozone_"coritactor influent and effluenl valves to allow flow through contactor.
.. Initiate ozone ·dosing to coritactor via SCADA by selecting the off-line contactor to transition on-line.
Onc:e this command is·tnitiated, which ever flow meter measuring the entire p.lant flow has been
selected .(raw water Influent flow from Facllity-11 or treated water flow from the Chemical Mix Chamber) ..
Is divided 50/50 to both contactors for ozone dose via flow _pacing. · ·
" After establlshing the required ozone lnactlyation for Glardfa and Virus, slowly return treated water flow
to the clearwells by returning the BACC's from Off-line td On-line.
Until the event of April 21, 2019, this procedure had functioned without inc1dent. The circumstances surrounding
the failure on the evening of Aprfl 21, 2019 are Identified In the following bullet items:
• · The.on-duty operator performing this task did nof visu_aliy monitor the opening of the valves ensuring botli
the lnJluent and effluent valves had fully opened.allowing full flow through the contactor.
• An OPEN 9ommand was lnitlated·to the actuator and the on-duty operator assumed it would fully open
correctly however the actuator only opened approximately 8-inches !~stead of the required 53-inches.
.j
!
., This condition resulted In an estimated flow of between 8 to 10-MGD through the contador, wlth the
majority of the 68-MGD flowing thro.ugJ, the original In-service ozone contactor. Note: Flow data Indicate
periods of 75-MGO were also experienced during this time.
ca . As ?I result o_fthls valve faflure, the flow value was mathematically spilt via SCAOA 50/50 between. the two
contactors which resulted in the contactor reeeivlng the bullc of the flow incorrectly dosln_g the actual flow.
.. This situation existed from 9:00 SPM April 21, 2019 until the failed actuator Was observed by a second . .
on-duty operator at approxin1ately 12:50 PM April 22, 2019.
· • Total plant t~eated wa_te.r_flow was adjusted to approximately 55-MGD at 9:00 AM April 22, 2019 with a
reduced Treated Water Flow demand.
During this approximately 12~hour time the lowest calculated inactivation was·Giardia 0.17-Log, Virus 1.35~J..og
The following tasks and procedures. will be Implemented to prevent reoccurrence of this failure:
. .
" lJpdate Contactor lsoiation SOP to ·include operator visual verification that all isolation valves are either
fu_lly clo~e or fully open as cbmmanped. ·
(I) Revise and discuss SOP revisions with all staff.
,. Add visual reference to valve steni with red.and gr-een marks to clear PVC housing indicating fully open
.and fully closEld valve stem positions.
• Pull wire. to PLC-45 to prqvlde discreet valve position and fall alarms to SCADA.
• In plant SCADA HMJ will generate. a warning ·message wtien both ozone contactors are In service and the
difference between normalized ratios between contactors exceed a predetermined s-elected setpolnt. This
alarm will ~Uow operations to detect nota.bly different conditions In dislnfectton. Since all otner parameters
are measured and controlled withirl closed loop qontrollers, the only parameter left-is the flow. The flow
will be the· mclin disturbance which wlll affect the normalized ratio between desire(! and· actual dose · ·
achieved. This warning message will be dlsp"iayed.on a.pop0up screen with a detailed explariEitlon ofthe·
cause and requlr.ed acttons to !1)itfgate the flow unbalance, · ·
Please do not hesitate to contact me tf ariy follow up Information is needed.
Regards,
Brian MacDonald
Jaeobs .
Plant M_anager'
Twin Oaks Valley WTP
Copies to: Chris Castaing, Operations & Maintenance Manager, San Diego. County Water Authority
Dennis Burrell~ Regional Manager, Jacobs Engineering
Enter Document No. via Docum_ent Properties 2
Citation No. 05-14-19C-003
APPENDIX3
DRINKING WATER NOTIFICATIONS TO CONSUMERS
PROOF OF NOTIFICATION
Nanie of W~ter System: ___ _
Please explain what caused the problem if you have determined what it was and Whqt steps you
have taken to correct it. ·
C,onsumers Notified ____ Yes No ----
If not," ~xplain: ________ ....,...... __ _
D~te of Notification: ____ _
O~ the date of notification set forth above, I served the above referenced document(s) on the
consumers by: ·
Sending a copy through the U.S. Mail,·first class, postage· prepaid, addressed to each
of the resident(s) at the place where the property is.situated, pursuant to the 9alifornia
· Civil Code. Attach copy of Notice.
Newspaper (if the problem has been corrected). Attach ~ copy of Notict3 .
. Personally hand-delivering a copy to each of the consumers. Attach a ~opy of Notice .. ·
Posted on a public bulletin board, that will be seen by each of the consumers (for small,
non-community water systems with prior Department approval). Attach copy. of Notice.
I hereby declare the forgoing to be true and correct under penalty of perjury.
Pate ·. Signature of Person Serving Notice
** ·Notice: Complete this Proof of Notification and return ft along with ·a copy of the notification
to the Department Within 1 O days of posting the notification. ·
Disclosure: Be advised that the California Health and Safety Code states that any person who
knowingly makes a false statem,ent on any report or d9cument submitted for the purpose of
compliance with the attached order may be liable for a civil penalty not to exceed five thousand
dollars ($5,000) for each separate violation for each day that violation continues. In addition, the
violatqrs may be prosecuted in criminal court and upon conviction, be punished by fine of not more
than twenty-five thousand dollars ($25,000) for each day ofviolatiort, or be !!TI Prisoned in ~6unty jail
not to exceed one year or by both the fine and imprisonment. · ·
8jPage
Citation No. 05-14;.19C-003
APPENDIX 4-NOTIFICATION OF RECEIPT ·
Citation Number: 05-14-19C-Q03
Name of Water System: San Diego County Water Authority
System Number: 3710042
Certification
I certify that I am an authorized representative of San Diego County Wafer Authority and that
Citation No. 05-14~19C-003 was received on ________ .· Further I certify that the
Citation has been reviewed by the appropriate management staff of the San Diego County Water
Authority and it is clearly understood that Citation No. 05-14-19C-OQ3 contains legally enforceable
. directives with specific due dates.
Signature of Water System Representative Date
THIS FORM MUST BE COMPLETED AND RETURNED TO THE STATE WATER BOARD,
DIVISION OF DRINKING WATER, NO LATER ft-lAN JUNE 11 , 20'1Q.
Disclosure: Be advised that the California Health and Safety Code; Sections 116725 and 116730
state that any person who knowingly makes any false statement on any report or document
submitted for the purpose of compliance with the Safe Drinking Water Act may be liable for,
respectively, a civil penalty not to exceed five thousand dollars ($5,000) for each separate violation
or, for continuing violations, for each day that violation continues; or be punished by a fine of not
more than $25,000 for each day of violation, or by imprisonment in the county jail not to exceed one
year, or by both the fine and imprisonment.
91Pa~e
Our Region's Trusted Water Leader
San Diego County Water Authority
Water Quality Notification
June 2019
June 2019
■ A brief treatment process.malfunction at the Twin Oaks Valley Water Treatment Plant
on April 21, 2019, resulted in a Notice of Violation from the state Division of Drinking
. Water.
o The malfunction lasted for about twelve hours, when ozone residuals in the plant ·
fell below state-mandated levels.
· • Ozone is a widely used disinfectant in water treatment systems, and part of
the treatment process at Twin Oaks.
o This is the first NOV issued at the Twin Oaks plant in more than a decade of
service.
o The fa,ilure was the result of a valve failing to fully open.
o A contractor (CH2M Hill/Jacobs) opera,tes the plant, but the NOV is issued to the.
Water Authority as the owner/penhit holder.
■ Overall water quality was not compromised, and there is no public health concern due
to multiple safeguards in place.
o Residents don't need to boil water or take other precautions.
o Water quality continued to meet all state and federal standards. .
o If there had been an emergency,people would have been notified immediately.
o Corrective actions were taken immediately and the lapse was reported to state
regulators.
o The contractor has updated its operational procedures and installed additional
monitoring equipment to prevent future problems.
■ Although this is not an emergency, wat~r users are entitled to know what happened and
what was done to correct the problem.
o The total number of customers affected is stiH being determined.
o We will be notifying all customers who potentially received water fr01i1 Twin
Oaks during the failure; we are working with our member agencies to identify
those customers.
o Affected agencies include Valley Center, Vallecitos, Rincon, Rainbow,
Oceanside, Vista, Carlsbad, Ramona, Padre Darn, Otay, Helix and the City of San
Diego.
■ For public inquiries about this situation, please call the Water Authority's Escondido
office at-760-480-1991.
https://sdcwaoffice365.sharepoint.com /sites/intranet/poc/SitePages/key-points.as px
To the members of the:
C COUNCIL
Da CA Vee ✓
CM ..LoeM (3) i£
Council Memorandum
June 28, 2019
To:
. From:
Honorable Mayor Hall and Members of the City Council
Paz Gomez, Deputy City Manager, Public Works
(c~;;~t B
Carlsbad
Memo ID# 201907 4
Via:
Re:
Vicki Quiram, General Manager, Carlsbal:· Municipal Water District
Elaine Lu key, Chief Operations Officer ~ ·
Additional Information on the San Dieg · County Water Authority Twin Oaks
Water Treatment Plant
This memorandum provides an update to the memorandum sent to the City Council on June 17,
2019, regarding a recent malfunction at the San Diego County Water Authority (Water
Authority) Twin Oaks Water Treatment Plant.
Background/Discussion
The June 17, 2019, memorandum provided an overview of the malfunction at the Twin Oaks
Water Treatment Plant, of the subsequent issuance of a Notice of Violation from the State
Water Quality Control Board Division of Drinking Water, and of the public notification
requirements related to the malfunction. The memorandum is attached for reference.
Based on initial discussions with the Water Authority, staff had informed the City Council via
the prior memorandum that public notices would be mailed to customers on or about July 1,
2019. The Water Authority has recently informed member agencies that public notices will be
delayed to July 8, 2019, or later.
Next Steps
A copy of the public notice and associated press release will be forwarded to the City Council
once these documents have been received.
Attachment: Council Memorandum dated June 17, 2019
cc: Scott Chadwick, City Manager
Celia Brewer, City Attorney
Laura Rocha, Deputy City Manager, Administrative Services
Amanda Guy, Deputy City Attorney
Kristina Ray, Communications Manager
Public Works Branch
Faraday Center 1635 Faraday Avenue I Carlsbad, CA 92008 I 760-602-2730
_J
7
IMPORTANT INFORMATION ABOUT YOUR DRINKING WATER
The San Diego County Water Authority
Did Not Meet Treatment Requirement (Disinfection)
The San Diego County Water Authority is a wholesale water provider
that treats and sells drinking water to your local retail water agen-
cy for distribution to homes and businesses. The Water Authority
recently experienced a treatment process failure at its regional treat-
ment plant. Due to additional treatment processes that are in place,
the water in regional pipelines continued to be safe for all uses.
Although this was not an emergency, customers have a right to know
what happened, what we are doing to correct this situation, and
what they should do. You do not need to boil your water or take
other actions.
On April 21-22, 2019, water in the Water Authority's treatment plant
was not in contact with the proper dosage of a disinfectant called
ozone for the required amount of time. The Water Authority imple-
mented policy and engineering changes to immediately identify and
correct improper valve conditions that led to the April 21-22 incident.
If there had been an emergency, people would have been notified
immediately.
For more information, contact the Water Authority at (858) 284-4142
or go to www.sdcwa.org/water-quality.
INFORMACION IMPORTANTE ACERCA DE SU AGUA POTABLE
San Diego County Water Authority
incumpli6 con requisito de tratamiento (desinfecci6n)
La San Diego County Water Authority es un proveedor mayorista de
agua que trata y vende agua potable a su agencia minorista de agua
local para ser distribuida a los hogares y negocios. La Water Authority
experimento recientemente una fa Ila en el proceso de tratamiento
de su planta tratadora de agua regional. Sin embargo, debido a los
tratamientos adicionales que se realizan, el agua de las tuberias
regionales permaneci6 segura para todos los usos.
Aunque esto no fue una emergencia, los clientes tienen derecho a
saber lo que sucedio, lo que estamos haciendo para corregir esta
situacion, y lo que ellos pueden hacer. Usted no necesita hervir el
agua o tomar otras medidas.
El 21 y 22 de abril de 2019, el agua en la planta de tratamiento de
la Water Authority no recibio la dosis adecuada de un desinfectante
llamado ozono durante el tiempo requerido. La Water Authority ha
implementado cambios en sus normas e ingenierfa para identificar y
corregir inmediatamente cualquier condicion incorrecta de las valvu-
las que produjeron el incidente del 21 y 22 de abril. Si hubiera sido
una emergencia, las personas habrfan sido notificadas de inmediato.
Para mas informacion, por favor comuniquese con la Water Authority
al (858) 284-4142 o visite www.sdcwa .org/water-quality.
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San Diego County Water Authority
4677 Overland Ave.
San Diego, CA 92123
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Attachment D
Our Region's Trusted Water Leader
San Diego County Water Authority
Media Contact:
Ed Joyce
(858) 522-6716 office
(949) 276-1675 cell
Ejoyce@sdcwa.org
July 8, 2019
4677 Overland Avenue, San Diego, CA 92123
News Release
Twin Oaks Valley Water Treatment Plant Cited for Error
Overall water quality not compromised, but customers are being notified
A malfunction at the Twin Oaks Valley Water Treatment Plant resulted in a citation from the
state Division of Drinking Water, though the water in regional pipelines continued to be safe for
all uses due to additional treatment processes that are in place.
The malfunction lasted for about 15 hours on April 21-22, when ozone dosage levels in the plant
fell below state-mandated levels because a valve failed to fully open. Ozone is a common
disinfectant used in water treatment systems to kill bacteria and other organisms. To be effective,
water must be in contact with the proper dosage of ozone for specific amounts of time.
CH2M Hill/Jacobs operates the Twin Oaks plant under a contract with the Water Authority, but
the citation was issued to the Water Authority as the plant owner and permit holder. This is the
first citation issued at the Twin Oaks plant in more than a decade of service.
Corrective actions were taken immediately, and the lapse was reported to state regulators. The
contractor has updated its operational procedures and installed additional monitoring equipment
to prevent similar problems in the future.
If there had been a water quality emergency, the public would have been notified immediately.
After the citation was issued on June 4, the Water Authority worked closely with impacted
member agencies to follow state-mantled noticing requirements.
"This was an unfortunate event, and we've put new procedures and equipment in place to ensure
it doesn't happen again," said Sandy Kerl, acting general manager of the Water Authority. "We
are committed to maintaining the high levels of safety and reliability we've achieved over more
than 75 years of service to the San Diego region."
That process involved identifying and notifying all customers who may have received water
from the Twin Oaks plant during the April 21-22 incident. Affected agencies are Carlsbad
Municipal Water District, Helix Water District, City of Oceanside, Otay Water District, Padre
Darn Municipal Water District, Rainbow Municipal Water District, Ramona Municipal Water
District, Rincon del Diablo Municipal Water District, Vista Irrigation District, City of San
Diego, Vallecitos Water District, and Valley Center Municipal Water District. Notices in English
and Spanish are being mailed to potentially affected customers this week.
The notices include a hotline number that Water Authority set up to address questions from the
public at (858) 284-4142. In addition, the Water Authority has provided online resources at
www.sdcwa.org/water-quality. Those resources include a map of affected areas searchable by
address, the official public notice, the formal citation by the state and frequently asked questions.
During June, retail water agencies are distributing their annual water quality reports to
customers. The Twin Oaks incident is not included in the current reports, which cover water
quality during calendar year 2018. Since the event occurred in April 2019, it will be noted in the
annual reports for calendar year 2019 which will be released next year.
###
The San Diego County Water Authority sustains a $231 billion regional economy and the quality
of life for 3. 3 million residents through a multi-decade water supply diversification plan, major
infrastructure investments and forward-thinking policies that promote fiscal and environmental
responsibility. A public agency created in 1944, the Water Authority delivers wholesale water
supplies to 24 retail water providers, including cities, special districts and a military base.
m
11\~ https://www.instagram.com/sdcwa
http://www.twitter.com/sdcwa @sdcwa
Dhttp://www.facebook.com/SanDiegoCountyWaterAuthority
f :;l slideshare ·-· · -http://www.slideshare.net/waterauthority
v·ou l:B http://www.youtube.com/SDCWAvideo
Attachment E
IMPORTANT INFORMATION ABOUT YOUR DRINKING WATER
Este informe contiene informaci6n muy importante sobre su agua potable.
Traduzcalo o hable con alguien que lo entienda bien.
San Diego County Water Authority
Did Not Meet Treatment Requirement (Disinfection)
The San Diego County Water Authority is a wholesale water provider that treats and
sells drinking water to your local retail water agency for distribution to homes and
businesses. The Water Authority recently violated a drinking water standard. Although
this was not an emergency, our customers have a right to know what they should do,
what happened, and what we are doing to correct this situation.
To ensure proper disinfection, water in the treatment plant must be in contact with the
proper dosage of ozone, or other similar disinfectant, for a specified period. On April 21-
22, 2019, this did not occur. Although ozone is able to inactivate and/or kill most
bacteria and organisms such as viruses and parasites, it requires the proper dosage be
applied to the water. The amount of ozone, or dosage, depends on the amount of
contact time with the water and the temperature of the water.
The water in regional pipelines continued to be safe for all uses due to additional
treatment processes that are in place. However, state regulations require that the San
Diego County Water Authority notify all customers who may have received water treated
on April 21-22. The notice was required within 30 days of the formal citation issued by
state regulators on June 4, 2019. The Water Authority was granted an extension to
avoid sending the notices over a holiday weekend. If there had been an emergency,
people would have been notified immediately.
What should I do?
• You do not need to boil your water or take other actions.
• This is not an emergency. If it had been, you would have been notified
immediately. Tests taken during this same time period did not indicate the
presence of bacteria in the water.
• Inadequately treated water may contain disease-causing organisms. These
organisms include bacteria, viruses, and parasites that can cause symptoms
such as nausea, cramps, diarrhea, and associated headaches. These symptoms,
however, are not caused only by organisms in drinking water, but also by other
factors. If you experience any of these symptoms and they persist, you may want
to seek medical advice.
• People with severely compromised immune systems, infants, and some elderly
may be at increased risk. These people should seek advice about drinking water
from their health care providers. General guidelines on ways to lessen the risk of
infection by microbes are available from U.S. EPA's Safe Drinking Water Hotline
at 1 (800) 426-4791.
• If you have other health issues concerning the consumption of this water, you
may wish to consult with your doctor.
What happened? What is being done?
On April 21-22, 2019, a valve failed to fully open resulting in an uneven flow through the
ozonation process within the treatment plant. This resulted in a portion of the flow not
receiving the proper ozone dosage. Once discovered, measures were taken to correct
the plant's operation. Follow-up actions have been implemented, including policy and
engineering changes to immediately identify and correct improper valve conditions.
For more information, please contact the San Diego County Water Authority at (858)
284-4142 or 610 West 5th Avenue, Escondido, CA 92025. Additional information is at:
www.sdcwa.org/water-quality.
Please share this information with all the other people who drink this water, especially
those who may not have received this notice directly (for example, people in
apartments, nursing homes, schools, and businesses). You can do this by posting this
public notice in a public place or distributing copies by hand or mail.
Secondary Notification Requirements
Upon receipt of notification from a person operating a public water system, the following
notification must be given within 10 days [Health and Safety Code Section 116450(9)]:
• SCHOOLS: Must notify school employees, students, and parents (if the students
are minors).
• RESIDENTIAL RENTAL PROPERTY OWNERS OR MANAGERS (including
nursing homes and care facilities): Must notify tenants.
• BUSINESS PROPERTY OWNERS, MANAGERS, OR OPERATORS: Must
notify employees of businesses located on the property.
This notice is being sent to you by the San Diego County Water Authority.
State Water System ID#: 3710042. Date distributed: July 8, 2019.
Attachment F
Our Region's Trusted Water Leader
San Diego County Water Authority
Water Quality FAQs -July 2019
1. What happened?
• The Twin Oaks Valley Water Treatment Plant experienced a treatment process failure on
April 21-22, 2019. The malfunction lasted for about 15 hours, when ozone dosage
levels in the plant fell below state-mandated levels. The failure was the result of a valve
failing to fully open.
2. What are ozone residuals?
• Ozone is a widely used disinfectant in water treatment systems and part of the
treatment process at Twin Oaks.
3. Was my health jeopardized by this failure?
• No. The wc1-ter in regional pipelines continued to be safe for all uses due
to additional treatment processes that are in place.
• Water quality testing during and after the event did not indicate the presence of bacteria
in the water.
• No precautions need to be taken.
4. Do I need to boil my water?
• Residents don't need to boil water or take other precautions.
5. How do you know my water was safe?
• There were other treatment processes in place that provided the required level of
treatment.
• Water quality testing during and after the event did not indicate the presence of bacteria
in the water.
6. What other treatment processes were in place that helped to maintain water quality?
• The other treatment processes in place are membrane filtration and chlorination.
7. Why was the public not contacted immediately when the failure happened?
• This was not an emergency. If it had been, you would have been notified immediately.
• State regulators were notified of the treatment process malfunction.
• The Water Authority is following noticing requirements set by state regulators.
8. Should I consult a doctor?
• It has been determined in consultation with the state Division of Drinking Water staff that
overall water quality was not compromised.
• Multiple barriers and processes in place ensured continuous protection.
• If you are concerned, you may wish to consult a health professional.
9. Can I talk with someone about this incident?
• Yes. The Water Authority has set up a hotline at (858) 284-4142.
10. Has the treatment plant fixed the problem?
• Yes. The facility has updated its operational procedures and installed additional
monitoring equipment to prevent future problems.
11. Was my water district among the affected agencies?
• We are mailing postcards to notify customers who potentially received water from Twin
Oaks on April 21-22.
• Affected agencies include Carlsbad Municipal Water District, Helix Water District, City
of Oceanside, Otay Water District, Padre Dam Municipal Water District, Rainbow
Municipal Water District, Ramona Municipal Water District, Rincon del Diablo
Municipal Water District, Vista Irrigation District, City of San Diego, Vallecitos Water
District, and Valley Center Municipal Water District.
12. Was my home affected?
• Residents can use a searchable map at www.sdcwa.org/water-quality to determine if their
house may have received water from Twin Oaks plant during the citation period.
13. Why is this not mentioned in the Drinking Water Quality Report that I recently
received from my water provider?
• Because of the timing ofthis event, it's notincluded in the 2018 reports that are
currently being issued by retail water agencies. However, affected agencies will note it in
next year's reports.
14. How do I inform my employees, students or tenants about this incident?
• The official state notice is posted at www.sdcwa.org/water-guality. Provide a link or a
hardcopy of the notice to tenants, employees or students in accordance with state health
codes. Click here for secondary noticing requirements in State Health and Safety Code
Section 116450(g).