Observations of Observations of WeekdayWeekday--Weekend Activity Weekend Activity

Patterns for Area Sources in the Patterns for Area Sources in the Los Angeles AreaLos Angeles Area

Dana L. Coe, Courtney A. Gorin, Lyle R. Chinkin, and Stephen ReiDana L. Coe, Courtney A. Gorin, Lyle R. Chinkin, and Stephen ReiddSonoma Technology, Inc.Sonoma Technology, Inc.

Presented at thePresented at theU.S. EPA 12U.S. EPA 12thth Annual Emission Inventory Conference,Annual Emission Inventory Conference,

“Emission Inventories: Applying New Technologies”“Emission Inventories: Applying New Technologies”April 28 April 28 -- May 1, 2003May 1, 2003San Diego, CaliforniaSan Diego, California

STI Document No. 2278

2

Weekend Effect in Los AngelesWeekend Effect in Los AngelesLos Angeles ozone air quality Los Angeles ozone air quality improved from 1980 to 1999.improved from 1980 to 1999.•• No. of 1No. of 1--hr exceedances hr exceedances

decreased from about 150 to only decreased from about 150 to only 50 per yr.50 per yr.

Weekend (WE) peaks Weekend (WE) peaks ��weekday (WD) peaks.weekday (WD) peaks.•• From 1980From 1980--99, WD99, WD--WE difference WE difference

became more pronounced.became more pronounced.

•• How can this be if WE precursor How can this be if WE precursor emissions are lower?emissions are lower?

Source of figure: Austin, J.; Tran, H. “A Characterization of the Weekend-Weekday Behavior of Ambient Ozone Concentrations in California”; Draft staff report prepared by the Technical Support and Planning Division, California Air Resources Board, Sacramento, CA. 1999.

3

Purpose & ObjectivesPurpose & ObjectivesPurposePurpose: Address a lack of WE: Address a lack of WE--specific emissions specific emissions

data, which are needed to support air quality data, which are needed to support air quality modeling exercises for WE conditions in Los Angeles.modeling exercises for WE conditions in Los Angeles.

ObjectivesObjectives::Characterize WDCharacterize WD--WE activity patterns for certain types WE activity patterns for certain types

of area sources in Los Angeles.of area sources in Los Angeles.Coordinate with concurrent data collection efforts:Coordinate with concurrent data collection efforts:

•• InIn--vehicle travel activity measurementsvehicle travel activity measurements•• Monitoring of traffic volumes on surface streetsMonitoring of traffic volumes on surface streets•• Acquisition of freewayAcquisition of freeway--based traffic volumes based traffic volumes •• Acquisition of continuous emissions monitoring systems Acquisition of continuous emissions monitoring systems

(CEMS) data for major stationary point sources(CEMS) data for major stationary point sources

4

Some residential activities (RAs) in Los Angeles Some residential activities (RAs) in Los Angeles increase from WD to WE by 25% to 165% increase from WD to WE by 25% to 165% (e.g., BBQs, recreational boats, recreational RVs). (e.g., BBQs, recreational boats, recreational RVs).

Other RAs vary little by day of week (DOW) Other RAs vary little by day of week (DOW) (e.g., personal care products, water heating).(e.g., personal care products, water heating).

Diurnal distributions of some RAs vary by DOW.Diurnal distributions of some RAs vary by DOW.•• On On WDsWDs, BBQ use occurs primarily in the , BBQ use occurs primarily in the

evening, but on evening, but on WEsWEs the afternoon share of use the afternoon share of use increases significantly.increases significantly.

Summary of FindingsSummary of Findings

WDWD WEWE

5

Business activities (BAs) in L.A. decline from WD to Business activities (BAs) in L.A. decline from WD to WE by 60% to 99% (e.g., construction).WE by 60% to 99% (e.g., construction).

Most BAs peak 8 a.m. to 4 p.m. on Most BAs peak 8 a.m. to 4 p.m. on WDsWDs and Sat, but and Sat, but are flat on Sun. are flat on Sun.

•• Exceptions are construction, lawn/garden Exceptions are construction, lawn/garden services, and use of gas ovens.services, and use of gas ovens.

Summary of FindingsSummary of Findings

WDWD WEWE

6

ApproachApproachWhat?What? Telephone and mail surveysTelephone and mail surveys

Who?Who? Residences and small businessesResidences and small businesses

When?When? Summer of 2002, May 17Summer of 2002, May 17--Sept 16.Sept 16.

Where?Where? Half of respondents were drawn randomly Half of respondents were drawn randomly from throughout the South Coast Air Basin.from throughout the South Coast Air Basin.

Five neighborhoods of Los Angeles (L.A.) were Five neighborhoods of Los Angeles (L.A.) were selected to corroborate past results and to selected to corroborate past results and to coordinate with concurrent WDcoordinate with concurrent WD--WE mobile WE mobile source measurements. source measurements.

7

Selected NeighborhoodsSelected Neighborhoods

8

Results: Residential ActivitiesResults: Residential ActivitiesSome RAs increased from Some RAs increased from WDsWDs to to WEsWEs by 25% to by 25% to 165%, including uses of: 165%, including uses of:

•• barbecues*barbecues*

•• recreational boats*recreational boats*

•• recreational offrecreational off--road RVs*road RVs*

•• paints or solvents*paints or solvents*

Some RAs varied <25% by Some RAs varied <25% by DOW, including uses of:DOW, including uses of:

•• personal care productspersonal care products

•• water heatingwater heating

*see plot *see plot

0%

5%

10%

15%

20%

25%

30%

BBQ Rec.Boats

Rec.Off-Rd

RVs

Paint/Solvent

Est

imat

ed D

OW

Allo

catio

n F

acto

r .

Mon-Thurs Friday Saturday Sunday

9

Results: Residential ActivitiesResults: Residential ActivitiesSome RAs occurred at certain times of day:Some RAs occurred at certain times of day:•• Evening: WD BBQ use*Evening: WD BBQ use*•• Afternoon: Recreational boatsAfternoon: Recreational boats•• Morning: personal care products*Morning: personal care products*

Some RAs had DOWSome RAs had DOW--dependent patterns.dependent patterns.•• WD BBQ use*: 8% to 12% of total in afternoon; WD BBQ use*: 8% to 12% of total in afternoon;

90% in evening90% in evening•• WE BBQ use*: 24% to 33% of total in afternoon; WE BBQ use*: 24% to 33% of total in afternoon;

66% to 74% in evening66% to 74% in evening

Some RAs had DOWSome RAs had DOW--independent independent patterns.patterns.•• personal care products*personal care products*•• water heating water heating

*see plot *see plot

Personal Care Products

0%

20%

40%

60%

80%

100%

Mo-

Th

(N=

84

5)

Fri

(N

=4

12

)

Sa

t(N

=4

46

)

Su

n(N

=4

04

)

Barbecues

0%

20%

40%

60%

80%

100%

Mo-

Th

(N=

10

2)

Fri

(N=

60)

Sat

(N=

72)

Su

n

(N=

10

0)

Diu

rnal

Dis

trib

utio

ns

10

Results: Business ActivitiesResults: Business Activities

99%99%90%90%ConstructionConstruction

80%80%61%61%Gas OvensGas Ovens

82%82%74%74%All Businesses All Businesses (Aggregate)(Aggregate)

WDWD--toto--Sun Sun

% Reduced% Reduced

WDWD--toto--Sat Sat

% Reduced% ReducedBusiness TypeBusiness Type

0%

5%

10%

15%

20%

25%

All Bus

ines

s

Office

s

Oth

er W

orkp

lace

Mot

or O

ils

Gas

Ove

ns

Pestic

ides

IC E

ngines

Paint

s

Gar

den

Equip

Con

stru

ction

DO

W A

llo

cati

on

Facto

rWeekdays Saturday Sunday

11

Results: Business ActivitiesResults: Business ActivitiesAggregate:Aggregate:

•• On WD, BA peaks from 8 a.m.On WD, BA peaks from 8 a.m.--4 p.m.4 p.m.

•• On WE, BA evenly distributed 8 a.m.On WE, BA evenly distributed 8 a.m.--12 a.m.12 a.m.

Lawn and Garden

0%

20%

40%

60%

80%

100%

Weekday Saturday Sunday

Diu

rnal

Dis

trib

utio

n

0%

20%

40%

60%

80%

100%

Weekday Saturday SundayAll Construction Companies

8pm-midnight

4pm- 8pm

noon- 4pm

8am- noon

4am- 8am

midnight-4am

Gas Ovens0%

20%

40%

60%

80%

100%

All Businesses0%

20%

40%

60%

80%

100%

Diu

rnal

Dis

trib

utio

n

TypeType--specific:specific:

•• BA with gas ovens BA with gas ovens is sustained late into is sustained late into the evening and the evening and latelate--night hoursnight hours

•• BAs of lawn/garden BAs of lawn/garden and construction and construction businesses peak businesses peak early, then drop off early, then drop off fast after 4 p.m.fast after 4 p.m.

12

Integration & ImplicationsIntegration & ImplicationsPreviously, we combined our RA and BA survey Previously, we combined our RA and BA survey

results with our findings from concurrent studies of results with our findings from concurrent studies of onon--road mobile and point sources.road mobile and point sources.

We applied our integrated findings to the California We applied our integrated findings to the California Air Resources Board’s emission inventories of NOAir Resources Board’s emission inventories of NOxx

and ROG for the South Coast Air Basin.and ROG for the South Coast Air Basin.

13

Integration & ImplicationsIntegration & Implications

0

300

600

900

1,200

1,500

RO

G

NO

x

RO

G

NO

x

RO

G

NO

x

RO

G

NO

x

RO

G

NO

x

Est

imat

ed E

mis

sion

s(t

ons

per

day)

Business Residential Mobile

Other Mobile Point Other

Summer M-Th Fri Sat Sun

Our corroborating and new results suggest that Our corroborating and new results suggest that WE emission reductions for several source WE emission reductions for several source categories will be even greater than the categories will be even greater than the previous estimates shown above.previous estimates shown above.

WDWD--WE Emissions: Year 2000WE Emissions: Year 2000

14

Integration & ImplicationsIntegration & ImplicationsWhat effects would be What effects would be expected?expected?

•• Increased Increased ROG:NOROG:NOxx

ratioratio

•• Decreased morning ODecreased morning O33

titration capacity by titration capacity by NONOxx

WE conditions are more WE conditions are more favorable forfavorable for

OO33 formation than WD formation than WD conditions.conditions.

Source of figure: Fujita, E.M., et al. “Weekend/Weekday Ozone Observations in the South Coast Air Basin: Retrospective Analysis of Ambient and Emissions Data And Refinement of Hypotheses, Volume I – Executive Summary”; Final report prepared for the National Renewable Energy Laboratory, December 2000.

15

AcknowledgmentsAcknowledgments

California Air Resources Board (ARB) California Air Resources Board (ARB) ––financial support and contract managementfinancial support and contract management

Mr. Leon Dolislager, ARB Mr. Leon Dolislager, ARB –– Technical Advisor Technical Advisor and ARB Project Officerand ARB Project Officer

Population Research Systems (San Francisco) Population Research Systems (San Francisco) ––implementation of telephone and mail surveysimplementation of telephone and mail surveys