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11615 Sterling Ave., Riverside, CA 92503 • 951.354.4220 • www.sawpa.org
S A W P A SANTA ANA WATERSHED PROJECT AUTHORITY
BASIN MONITORING PROGRAM TASK FORCE Tuesday, Sept. 19, 2017
1:00 p.m. – 3:30 p.m.
At SAWPA, 11615 Sterling Avenue, Riverside, CA 92503
AGENDA
1. Introductions
2. Public Comments
3. Approval of Aug 16, 2017 Meeting Summary
4. Formation of Consultant Review Committee - SAWPA
5. Triennial Ambient Water Quality Update – CDM Smith/DBSA
6. SAR Wasteload Allocation Model Update – Geoscience/Risk Sciences
7. So Cal Salinity Coalition Study Status – CDM Smith/DBSA/Risk Sciences
8. Future Meetings: October 18, 2017 change from 1:00 p.m. to 3:30 p.m.
discussion
9. Adjournment
K:\PROJECTS\PA-20 BASIN MONITORING PROG\MEETINGS\MINUTES\2017\8-16-2017\FINAL DRAFT BMP MEETING NOTES 8-16-17.DOC 1
M E E T I N G S U M M A R Y
Basin Monitoring Program Task Force
August 16, 2017
ATTENDEES: Ashley Gibson, YVWD Jesus Gastelum, EVMWD
Bobby Gustafson, City of Riverside Johnson Yeh, GeoScience
Cindy Li, Regional Board Joshua Aguilar, IEUA
David Jensen, CDM Smith, Inc. Marissa Flores-Acosta, SBMWD
Dennis Williams, GeoScience Mark Williams, GeoScience
Edgar Tellez Foster, CBWM Michael Cruikshank, DBSA
Edward Filadelfia, Riverside RWQCP Raul Arevalo, City of Corona
Fakhri Manghi, WMWD Robert Eland, Riverside RWQCP
Greg Herzog, City of Riverside PU Tim Moore, Risk Sciences
Greg Woodside, OCWD Mark Norton, SAWPA
Jayne Joy, EMWD Zyanya Blancas, SAWPA
Jeff Davis, SGPWA
Jennifer McMullin, City of Corona Phone: Al Javier , EMWD
Call to Order/Introductions The Basin Monitoring Program Task Force (Task Force) meeting was called to order at 1:33 p.m. at the Santa
Ana Watershed Project Authority (SAWPA) office located at 11615 Sterling Avenue, Riverside, California.
Brief introductions were made.
Public Comments There were no public comments.
Approval of June 13, 2017 Meeting Summary Meeting summary was approved with a minor modification.
Final 2016 Annual Report of Santa Ana River Water Quality – SAWPA Mark Norton reported that the Santa Ana River Water Quality Annual Report (Report) was finalized. Upon no
further comments from the Task Force, it was agreed to submit the final Report to the Regional Board.
Tim Moore, Risk Sciences, provided a summary of the changes that were made to the Report to prevent
accidently triggering a 303D impairment listing. He stated that a list was created of all the items that need
clarification in next year’s Report and will be brought up to the Task Force in January 2018.
Considering recent information, Mark Norton indicated that agenda items 5 and 6 are to be combined.
Supplemental Environmental Document & Economic Analysis Update – CDM Smith / SAR Wasteload Allocation Basin Plan Amendment Status – Risk Sciences/Regional Board Tim Moore, Risk Sciences, informed the Task Force that the Basin Plan Amendment to Revise the Chino South
Water Quality Objective for Nitrate was approved by Regional Board on August 4 and will now go to State
Board for final approval. As planned, the next process is to complete the Wasteload Allocation Basin Plan
Amendment.
It was discovered that the existing effluent limits for TIN and TDS in the current National Pollutant Discharge
Elimination System (NPDES) permits can be reauthorized without amending the Basin Plan to adopt a new
Wasteload Allocation (WLA); and no allocation of assimilative capacity is required to reauthorize the existing
effluent limits for TIN/TDS in the current NPDES permits issued to Rialto and RIX facilities. A rationale for the
statements was provided to the Task Force in a two-page document from Risk Sciences, along with a
DRAFT
K:\PROJECTS\PA-20 BASIN MONITORING PROG\MEETINGS\MINUTES\2017\8-16-2017\FINAL DRAFT BMP MEETING NOTES 8-16-17.DOC 2
Comparison of Effluent Limits in 2004 and 2015 WLA Model Runs table. The tables show that the effluent
levels that were used in the 2004 and the 2015 for Scenario 8 are identical and in a couple of cases its slightly
lower. With this information, it was determined that a Supplement Environmental Document or Economic
Document are not required for a WLA.
Triennial Ambient Water Quality Update Presentation – CDM Smith, Inc. Joe LeClaire, Daniel B. Stephens & Associates, Inc. (DBSA), indicated that comments to the draft results of the
Triennial Ambient Water Quality (AWQ) report are due by August 25, 2017 and upon review will then have the
final report to Regional Board by September 30.
Michael Cruikshank, DBSA, provided a PowerPoint presentation on the draft results of the AWQ. Cruikshank
briefly described DBSA’s process of obtaining the estimated volume-weighted AWQ in each groundwater
management zone. From the Groundwater Management Zone Boundaries and AWQ Objectives map it was
suggested that the contour maps of the bottom of aquifers should be updated since the ones that were used are
from the 1960-70s; new data from new wells have shown deeper aquifers. Discussion ensued regarding the
results of TDS and Nitrate data and changes in AWQ from 1996 to 2015.
As part of Task 1b, Update the physical model of Groundwater Management Zones (GMZ), DBSA was tasked
to pilot study the physical model of the Chino Basin GMZ to evaluate the effect of the update relative to the
AWQ results for 1996-2015. The results indicated that there was sufficient benefit to update the physical model
for other GMZs. The Task Force must now determine if the physical model is to be updated in the remainder of
the GMZs in the watershed in the 1999-2018 AWQ update.
SAR Wasteload Allocation Basin Plan Amendment Status – Geoscience Johnson Yeh, GeoScience, provided a PowerPoint presentation on TDS and TIN calibration results. The WLAM
boundaries has a total of 564 subareas were delineated including the 522 of the WLAM area. The variations in
the TDS vs time graphs reflect storm events that have lower TDS values for the Santa Ana River below Prado.
GeoScience will complete TDS/TIN recalibration of the WLAM. They will work with SAWPA staff, the Task
Force, and the Regional Board staff to specify range of portable discharge conditions and to identify percolation
ponds and retention basins where treated wastewater is regularly recharged to groundwater and where such
discharge are presently governed by permits issued by the Regional Board.
Tim Moore stated that he will work with GeoScience on the data request form to ensure that anticipated flows
needed for compliance are effectively considered and included in the WLAM.
Dewatering Project Permit Status from USACE – Regional Board/SAWPA The US Army Corps of Engineers (USACE) informed SAWPA that they will be submitting a check to
compensate for their share of modeling costs for the previous two years.
Southern California Salinity Coalition Study Status – CDM Smith/DBSA/Risk Sciences Joe LeClaire, DBSA, provided a PowerPoint presentation updating the Task Force on the preliminary results to
the TDS Trends Study, which is funded by the Southern California Salinity Coalition (SCSC). The Study will
determine what are the variables that are raising TDS levels and quantify the variables that cannot be managed
by the dischargers. Preliminary results from the pilot studies showed that Source TDS, state mandate
conservation, local conservation and Source Q. Discussion ensued regarding the variables that are
uncontrollable by the dischargers and how it has affected their individual discharges.
The goal is to have a draft report of this study to the SCSC Board at their September 7, 2017 meeting.
Future Meeting The next Basin Monitoring Program Task Force meeting is scheduled for Tuesday, September 19, 2017 at
1:00 p.m. and Wednesday, October 18, 2017 1:00 p.m.
DRAFT
K:\PROJECTS\PA-20 BASIN MONITORING PROG\MEETINGS\MINUTES\2017\8-16-2017\FINAL DRAFT BMP MEETING NOTES 8-16-17.DOC 3
Adjournment 3:24 p.m.
DRAFT
Santa Ana River Wasteload Allocation Model Update
September 19, 2017
BASIN MONITORING PROGRAM TASK FORCE
2
Model DevelopmentExisting WLAM (R4)
WLAM Update
Expanded Area
• 564 subareas were delineated.• Each subarea consists of
• Stream segment,• Pervious land area, and• Impervious land area.
• They were delineated based on:• Topography• Drainage Patterns• Types of stream channels, and• Location of gaging stations and recharge basins9/19/2017
3
Hydrologic Simulation Program Fortran -HSPF
9/19/2017
Precipitation
ET
Surface Runoff
Deep Percolation
Streambed Percolation
Infiltration
Interflow
• Comprehensive & Physically Based,
• Simulates ALL Water Cycle Components & Water Quality,
• Supported & Maintained by Federal Agencies (EPA & USGS),
• Established Standard Guidelines and Calibration Performance Criteria,
• Windows-Based Interface with Powerful Pre- & Post- Processors, and
• Software is Free.
4
Coupling Process of HSPF and OCWD Recharge Facilities Model (RFM)
9/19/2017
SAR Diversion
OCWD RFM
OutletPrado Inflow& Tributary
Streamflow to SAR (shown in
Yellow)
Step 1HSPF
Step 2OCWD RFM
Streamflow at OCWD
RFM Outlet
Step 3HSPF
Streamflow at SAR at Santa Ana
PradoDam
Recharge Basins
Calibration Process
5
• Adjust model parameters until the model provides a reasonable
match between the model-simulated and measured data.
• Lower zone nominal soil moisture storage,
• Base groundwater recession,
• Fraction of groundwater inflow to deep recharge,
• Fraction of remaining ET from baseflow,
• Interflow inflow parameter,
• Lower zone ET parameter,
• Function tables (FTABLE) which includes physical information (shape, depth,
width, slope, length, Manning Factor, and materials), and infiltration rates
for reaches of each sub-watershed, and
• Nitrogen reaction rate coefficient.
9/19/2017
6
Location of Streamflow Calibration Targets
9/19/2017
7
Location of TDS/TIN Calibration Targets
9/19/2017
Calibration Performance Criteria
8
Type of Flow Data R2 (Goodness-of-Fit) Calibration
Performance
Daily Flow R2 < 0.60 Poor
Daily Flow 0.60 < R2 < 0.70 Fair
Daily Flow 0.70 < R2 < 0.80 Good
Daily Flow R2 > 0.80 Very Good
Monthly Flow R2 < 0.65 Poor
Monthly Flow 0.65 < R2 < 0.75 Fair
Monthly Flow 0.75 < R2 < 0.85 Good
Monthly Flow R2 > 0.85 Very GoodSource: Donigian (2002)9/19/2017
9
Existing WLAM (R4)WLAM Update (HSPF)Daily Streamflow
SAR at MWD Crossing
0.1
1
10
100
1000
10000
100000
0.1 1 10 100 1000 10000 100000
Mo
de
l-C
alcu
late
d D
aily
Str
eam
flo
w, c
fs
Measured Daily Streamflow, cfs
R4 – WY 1995 to 2006
R2 = 0.68
Fair
0.1
1
10
100
1000
10000
100000
0.1 1 10 100 1000 10000 100000
Mo
de
l-C
alcu
late
d D
aily
Str
eam
flo
w, c
fs
Measured Daily Streamflow, cfs
HSPF – WY 2007 to 2016
R2 = 0.91
Very Good
9/19/2017
SAR at MWD Crossing
10
Existing WLAM (R4)WLAM Update (HSPF)Monthly Streamflow
0.1
1
10
100
1000
10000
100000
0.1 1 10 100 1000 10000 100000
Mo
de
l-C
alcu
late
d M
on
thly
Str
eam
flo
w, c
fs
Measured Monthly Streamflow, cfs
R4 – WY 1995 to 2006
R2 = 0.91
Very Good
0.1
1
10
100
1000
10000
100000
0.1 1 10 100 1000 10000 100000
Mo
de
l-C
alcu
late
d M
on
thly
Str
eam
flo
w, c
fs
Measured Monthly Streamflow, cfs
HSPF – WY 2007 to 2016
R2 = 0.97
Very Good
9/19/2017
Summary of Streamflow Calibration Performance
11
Gaging Station
Daily Streamflow Monthly Streamflow
2008 WLAM
(R4)
WY 1995-2006
WLAM Update
(HSPF)
WY 2007-2016
2008 WLAM
(R4)
WY 1995-2006
WLAM Update
(HSPF)
WY 2007-2016
San Timoteo Ck near Loma Linda Good Fair Good Fair
Warm Ck near San Bernardino Fair Fair Fair Very Good
Santa Ana River at E Street Good Very Good Very Good Very Good
Santa Ana River at MWD Crossing Fair Very Good Very Good Very Good
Temescal Ck at Main Street Poor Fair Good Poor
Chino Ck at Schaefer Avenue Fair Very Good Good Good
Cucamonga Ck near Mira Loma Poor Very Good Good Very Good
Santa Ana River into Prado Dam Fair Very Good Very Good Very Good
Santa Ana River at Santa Ana NA Poor NA Good
9/19/2017
Daily TDS at Santa Ana River at MWD Crossing
12
0
100
200
300
400
500
600
700
800
900
1,000
Oct-94 Oct-96 Oct-98 Oct-00 Oct-02 Oct-04 Oct-06 Oct-08 Oct-10 Oct-12 Oct-14
Mo
del
-Cal
cula
ted
Dai
ly T
DS,
mg/
L
WLAM Update (Mean Residual = -0.4 mg/L) 2008 WLAM (Mean Residual = 16.4 mg/L)
Observed
Model-Calculated
9/19/2017
Summary of TDS/TIN Calibration Performance
13
Gaging Station
TDS, mg/L TIN, mg/L
2008 WLAM
(R4)
WY 1995-2006
WLAM Update
(HSPF)
WY 2006-2016
2008 WLAM
(R4)
WY 1995-2006
WLAM Update
(HSPF)
WY 2006-2016
Santa Ana River at
MWD Crossing16.4 -0.4 -0.45 -0.40
Santa Ana River
below Prado Dam20.7 -2.0 -0.07 -0.28
Santa Ana River at Imperial Highway
near AnaheimNA 7.8 NA -0.21
9/19/2017
Summary
14
• The WLAM was updated with recent data and recalibrated from October 1, 2006 through September 30, 2016 (Water Years 2007 through 2016).
• The calibration results show:
• Good to very good performance at the majority of the streamflow gages .
• The streamflow calibration performance for the WLAM update is equal to or better than the 2008 WLAM at nearly all gages.
• TDS/TIN residuals from the WLAM update calibration are lower than the 2008 WLAM residuals for nearly all gages.
• The results indicate a satisfactory model calibration.
9/19/2017
Major Assumptions for Waste Load Allocation Scenarios
159/19/2017
Scenario Hydrology Land Use
MaximumDischarge
(Zero Recycled)
Planned Recycled / Discharge)
50% of Planned Recycled
A
WY 1950-2016
2012
X
B X
C X
D
General Plan(2040)
X
E X
F X
Discharge and Reuse Data
169/19/2017
City of CoronaCity of
Beaumont
City of Riverside
EVMWD SBVMWD WMWD
Facility WRF 1 RWQCPWWTP
001WWTP
002SNRC (City
Creek)WRCRW
Discharge(MGD)
Current
Design 11.5 4 46 8 8 0 14Max 11.4 3.30975 31.2 8 8 0 7.76Ave 3.4 2.9696 26.8 0.5 4.52 0 6.44Min 1.5 2.4232 21.8 0.5 4.5 0 5.22
2020
Design 11.5 46 12 12 7.5 14Max 11.5 33.8 12 12 7.5 10.3Ave 4.6 25 0.5 7 6.4 7Min 1.5 19 0.5 6.5 6 5.7
2040
Design 15 46 16.8 16.8 7.5 14Max 15 46 16.8 16.8 7.5 15.3Ave 8.5 22.5 0.5 14 6.4 10Min 1.5 19 0.5 13 6 8.5
Reuse of Recycled Water
(MGD)
Current
Max 7.1In house
only1.8 0.3 0.3 0 0
Ave 2.7In house
only0.9 0.2 0.2 0 0
Min 0In house
only0.6 0.2 0.2 0 0
2020Max 10 10 0.45 0.45 7.5 7Ave 2.7 4 0.3 0.3 6.4 3Min 0 1 0.2 0.2 6 0
2040Max 13.5 20 0.63 0.63 7.5 7Ave 3.5 16.5 0.42 0.42 6.4 3Min 0 3 0.2 0.2 6 0
Water Quality(mg/L)
TIN
Current Discharge Permit 10 6 / 3.6 10 13 NA NA 1012-mos. Average 5.5 / 5.2 4.34 4.5 2.5 NA NA 2.2
Est. 12 mos. Average in 2040 5.5 / 5.2 10 UnknownUnkno
wn6 2.2
TDS
Current Discharge Permit 700 / 770 400 / 300 650 700 700 NA 625
12-mos. Average 655 / 683 434 623 686 686 NA 529
Est. 12 mos. Average in 2040 655 / 683 650 UnknownUnkno
wn463 529
Discharge and Reuse Data
179/19/2017
EMWD IEUA City of Redlands City of San Bernardino YVWDFacility
Discharge(MGD)
Current
DesignMaxAveMin
2020
DesignMaxAveMin
2040
DesignMaxAveMin
Reuse of Recycled
Water(MGD)
CurrentMaxAveMin
2020MaxAveMin
2040MaxAveMin
Water Quality(mg/L)
TIN
Current Discharge Permit 12-mos. Average Est. 12 mos. Average in 2040
TDS
Current Discharge Permit
12-mos. Average
Est. 12 mos. Average in 2040
Evaluation of Wastewater Recharge in Percolation Ponds – Pilot Program
189/19/2017
• City of Redlands,• Coty of Corona,• IEUA, and• Dairy ponds in
Chino-North GMZ
19
QUESTIONS?
9/19/2017
Daniel B. Stephens & Associates, Inc.
Southern California Salinity Coalition
TDS Trends Study Update for the Basin Monitoring Program Task Force
September 19, 2017
Daniel B. Stephens & Associates, Inc.
Problem Statement
1. Evaluate the long-term trends for salinity in wastewater and recycled water
2. Assess how periodic droughts and various conservation measures may influence these trends
3. Primary Research Questions:
a. What portion of the increment from use (IFU) can be attributed to water conservation measures?
b. If trends of conservation measures continue, what portion of the IFU can be attributed to water conservation measures
Daniel B. Stephens & Associates, Inc.
18
18.5
19
19.5
20
20.5
21
21.5
22
22.5
23
0
0.5
1
1.5
2
2.5
3
3.5
4
4.5
5
Po
pu
lati
on
MW
DS
C S
up
pll
ies
(MA
FY
)
Local SuppliesImported SuppliesdPopulation
Conservation Measures
• Local and imported water supplies and population.
• The Metropolitan Water District of Southern California (2015)
Daniel B. Stephens & Associates, Inc.
0
100
200
300
400
500
600
700
800
900
1,000
2007 2008 2009 2011 2012 2013 2015 2016 2017
TDS
Co
nce
ntr
atio
n (
Mg
/L)
Temecula Valley Sewershed
Source
Effluent
Influent
Temecula Valley Discharge Limit: 750 mg/L
Problem Statement
• Increment from use (IFU) typically ranges from 200 to 250 mg/L.
• IFU can drive effluent TDS above the discharge limit.
• How much of IFU is due to conservation measures?
Daniel B. Stephens & Associates, Inc.
Study Approach
• Deterministic Model
– The outcome of a deterministic / algebraic model is governed through relationships between a state and an event. In the TDS trends study, the WWTP influent TDS is estimated from a measured concentration of source water and salt load from indoor use.
• Statistical Analyses
– Explores the relationship between the dependent variable (WWTP influent TDS) and independent (explanatory) variables, e.g., source concentration, population, conservation factors, etc.
Daniel B. Stephens & Associates, Inc.
Salt Mass Load
• AWWARF (2006).
• Comprehensive review of the “problem of salinity in reclaimed water on a national level.”
• “When water passes through municipal systems, it gains salts (‘salt pickup’), typically adding 200-400 mg/L TDS.”
Daniel B. Stephens & Associates, Inc.
Salt Mass Load
• Aligning terminology:
TDS Contribution = Mass salt load (MSL) (mass/time)
TDS Gain = TDS increment from use (IFU) (mg/L)
Daniel B. Stephens & Associates, Inc.
Contributions to MSL from Indoor Use
– about 45 grams/capita/day excreted in urine
– about half of this is in the form of urea, a soluble organics compound, which degrades over time (0.05 pounds / capita / day)
– Urea is not measured as a component of TDS
– Nall and Sedlak (2013) report human excretion at 72.8 grams / capita / day
Human excretion ≈ 70 grams / capita / day (0.154 pounds / capita / day)
Daniel B. Stephens & Associates, Inc.
0
50
100
150
200
250
300
350
400
450
500
40455055606570758085
Incr
emen
t fr
om
Use
TD
S (m
g/L
)
Indoor Water Use (gpcd)
Salt Load = 0.17 pounds per capita per day
Salt Load = 0.15 pounds per capita per day
1980 Indoor Water Use(77 gcpd)
2016 Indoor Water Use(52 gcpd)
Increase in TDS from MSLs from Indoor Use
• Increment from use (IFU) TDS concentrations resulting from a decrease of indoor water use at a range of salt mass loads (MSLs)
Daniel B. Stephens & Associates, Inc.
Study areas
1. Eastern Municipal Water District - EMWD (Pilot Study)
2. Inland Empire Utilities Agency - IEUA
3. San Bernardino Municipal Water District - SBMWD
4. Riverside Public Utilities - RPU
5. Orange County Sanitation Department- OCSD
6. San Diego County Water Authority - SDCWA
7. Los Angeles County Sanitation District - LACSD
Daniel B. Stephens & Associates, Inc.
1. EMWD
EMWD Sewersheds
• Moreno Valley
• Perris Valley
• San Jacinto Valley
• Temecula Valley
Daniel B. Stephens & Associates, Inc.
1. EMWD: Population & Indoor Water Use
• 2007
– Est. population of 650,000
– 70 gpcd
• 2016
– Est. population of 780,000
– 55 gpcd
Daniel B. Stephens & Associates, Inc.
1. EMWD: Deterministic Approach
• Increment of use:
– 2007: 250 mg/L
– 2016: 270 mg/L
• Influent ≥ Effluent suggesting no additional salt is being added to the system during the treatment process.
IFU: 250 mg/L
IFU: 270 mg/L
Daniel B. Stephens & Associates, Inc.
LOW FLOWREBATE
COMMERIAL PLUMBING RETROFITS
$ ↑ $ ↑
ULFT REBATES
$ ↑
HIGH-EFFICIENCYCLOTHES WASHERS
EMWD 10% WATER USE REDUCTION
$ ↑
HIGH-EFFICIENCYTOILET GIVEAWAY
$ ↑
HIGH-EFFICIENCYTOILET GIVEAWAY
STAGE 1: VOLUNARY 10%
WATER USE REDUCTION
$ ↑
EMWD TIERED-RATE
BEGINS
STAGE 2: MANDATORY 10%
WATER USE REDUCTION
EMWD LOOK TO RESTAURANTS TO MAKE EVERY DROP COUNT
EMWD SCHOOL GRANTSTO USE WATER WISELY
$ ↑ $ ↑
WRCOG PROGRAM:LOW INTEREST LOANS
FOR WATER CONSERVATIONIMPROVEMENTS
$ ↑ $ ↑ $ ↑ $ ↑ $ ↑
CLOTHES WASHERS/TOITETS/IRRIGATION CONTROLS
$ ↑
STAGE 3A:WATER SHORTAGE
CONTINGENCY PLAN
HIGH EFFICIENCY CLOTHES WASHERS/TOILETS
STAGE 4:28% MANDATORY
WATER USE REDUCTION
STAGE 4C:70% OUTDOOR USE REDUCTION
STAGE 4B:30% OUTDOOR USE REDUCTION
$ ↑
2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018
Conservation Program and Incentives
0.00
10.00
20.00
30.00
40.00
50.00
60.00
70.00
80.00
2002 2005 2008 2011 2014 2017
0
100,000
200,000
300,000
400,000
500,000
600,000
700,000
800,000
900,000
Wat
er U
se (
MG
D)
Po
pu
lati
on
Population and Water Use for EMWD Service Area
Population
Indoor Use
Daniel B. Stephens & Associates, Inc.
1. EMWD: Deterministic Approach
Cinf= (Masssource + MSL) / Qinf
• 2007
– Est. population of 650,000
– 70 gpcd (No additional conservation model input)
• 2016
– Est. population of 780,000
– 55 gpcd
Daniel B. Stephens & Associates, Inc.
1. EMWD: Statistical Approach
• MLA input variables
– Population***
– Source TDS***
– Influent Flow***
– State Mandate**
– PMDI**
– Source Flow
• IFU Difference: 55 mg/L
Daniel B. Stephens & Associates, Inc.
1. EMWD: Source Water Supply and Quality
• Constant groundwater supply over time
• Increased dependence of lower quality CRW during periods of drought especially significant in 2014
Daniel B. Stephens & Associates, Inc.
1. EMWD: Source Water Supply and Quality
• Constant groundwater supply over time
• Increased dependence of lower quality CRW during periods of drought especially significant in 2014
Daniel B. Stephens & Associates, Inc.
ClimateSource TDS and Drought
• Weymouth WTP
• Jensen WTP
• Diemer WTP
• Skinner
• Mills
• Castaic Lake
• Silverwood Lake
• Lake Mathews
Daniel B. Stephens & Associates, Inc.
1. EMWD: Perris Valley Influent Rolling Average
• Current discharge limits based upon 12-month rolling average
• Groundwater based upon 20-year rolling averages
Daniel B. Stephens & Associates, Inc.
Summary
• Previous studies
– AWWARF Study - Salt loads from indoor use
– Pacific Institute - Effects of historical and theoretical conservation measures on per capita indoor water use
– SCSC Study - Effects of drought and water conservation measures on WWTP influent water quality
• Observation data from groups of sewering agencies rather than individual WWTP is more reliable due to the following factors
– Population (city boundaries, sewershed boundaries)
– Operations can divert flows from plant to plant
Daniel B. Stephens & Associates, Inc.
Summary
• Quantify increase in IFU caused by conservation measures:
Sewershed Date Range Observed Deterministic Statistical
EMWD 2007 - 2016 20 mg/L 60 mg/L 55 mg/L
IEUA 1999 - 2016 70 mg/L 80 mg/L 90 mg/L
• Drought impacts both source water quality and an agency’s source(s) of supply.