HomeMy WebLinkAboutAgenda - 03-17-2015-13 (3)INFORMATION ITEM
To: Orange County Board of County Commissioners
CC: Bonnie Hammersley
From: Cheryl Young
Date: March 17, 2015
Attached for your review, please find a report from the ODUM institute regarding
surveys conducted during January/ February 2015 at the Solid Waste Convenience
Centers. In developing information for the multijurisdictional task force charged with
exploring collaborative solutions for solid waste issues confronting Orange County, a
survey was conducted of users of the Orange County Solid Waste Convenience
Centers. The purpose was to collect data with which to consider reapportioning the
usage of the solid waste convenience centers into two parts: usage by residents who
live in the incorporated areas of the county, and usage by residents who live outside the
incorporated areas. In addition, for those residents residing outside the incorporated
areas, information was gathered to ascertain if they would utilize curbside recycling if
available. The survey established that during the time of the survey, 89% of users lived
outside the incorporated areas. Of the users that did not have access to curbside
recycling, 62% said they would utilize curbside recycling if available. More detail,
including a description of the methodology utilized, is available in the report.
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711,111-
THE OIDUM INSTITUTE
The Odum Institute for Research in Social Science
Davis Library, 2 "d Floor, CB #3355
University of North Carolina at Chapel Hill
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SURVEY OF ORANGE COUNTY SOLID
WASTE CONVENIENCE CENTER USERS
FEBRUARY 25, 2015
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Orange County Solid Waste Management ( OCSWM) contracted with the H.W. Odum Institute
for Research in Social Science at the University of North Carolina — Chapel Hill (Odum) to assist
with the design and analysis of a survey of users of the County's five Solid Waste Convenience
Centers (SWCCs). The primary purpose was to collect data with which to apportion the usage
of the SWCCs into two parts: usage by residents who live in the incorporated areas of the
county, and usage by residents who live outside the incorporated areas. Other information
regarding recycling behavior and preferences was also collected. Odum statisticians worked
with OCSWM staff to devise a sampling and data collection plan to provide a "snapshot" view of
SWCC usage over a one week period for each site. OCSWM staff entered data from the
collected surveys into an application provided by the Odum Institute, and Odum statisticians
analyzed the data and wrote the report.
Across all days and sites, 89% of SWCC uses during the data collection period were made by
customers who live outside town limits and 11% by customers residing within town limits.
Eubanks Road SWCC received 30% of its uses by in -town residents. The other four SWCCs were
used almost exclusively by residents outside town limits, with 4% or less attributable to in -town
customers.
Forty -eight percent of surveyed customers reported having access to curbside recycling
services. Of these, 51% were nonetheless recycling at the SWCC the day they were surveyed,
most often because they were coming to the SWCC anyway to drop off trash or other items. Of
the customers who reported not having access to curbside recycling, 62% indicated that if they
did have it, they would use it. For both groups, reasons for not using (or wanting) curbside
recycling primarily had to do with the SWCC being more convenient, often because they have
to drop off trash anyway or because they have a long driveway or other reason that
maneuvering recyclables to the curb is difficult.
Thirty -two percent of surveyed customers report using a SWCC more than once a week, and
39% do so about once a week, meaning that (taking into account rounding) nearly 72% of SWCC
customers visit at least weekly.
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M
INTRODUCTION
Orange County Solid Waste Management ( OCSWM) contracted with the H.W. Odum Institute
for Research in Social Science at the University of North Carolina — Chapel Hill (Odum) to assist
with the design and analysis of a survey of users of the County's five Solid Waste Convenience
Centers (SWCCs). The primary purpose of the survey was to collect data with which to
apportion the usage of the SWCCs into two parts: usage by residents who live in the
incorporated areas of the county, and usage by residents who live outside the incorporated
areas. Information about recycling behavior and preferences was also collected. Odum
statisticians worked with OCSWM staff to devise a sampling and data collection plan to provide
a "snapshot" view of SWCC usage for a finite time period. OCSWM staff chose a time period
that was free of holidays or other events that might cause aberrations in SWCC usage, and
implemented the data collection plan. OCSWM staff entered data from the collected surveys
into an application provided by the Odum Institute, and Odum statisticians analyzed the data
and wrote this report.
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The following sections describe the survey instrument, sample design, and data collection
procedures for the survey.
SURVEY INSTRUMENT
OCSWM staff drafted the questions to be asked in the survey. Odum reviewed the draft for
adherence to best practices in survey methodology (clarity, unbiased wording, completeness of
response categories, etc.) and provided assistance with forms design. A copy of the
questionnaire is included as Appendix A.
IN /OUT OF TOWN LIMITS
The first and most important survey question asked the customer "Do you live within the town
limits of one of the towns ?" Though seemingly a straightforward question, a significant number
of Orange county residents do not know whether they live inside town limits. Therefore the
survey form itself and the training of the data collectors focused on additional questions and
techniques to confirm /clarify the customer's response.
The first clarification question asked whether the customer has curbside recycling available to
them. Unless they live in an apartment, the answer should be "yes" for all customers who live
in the incorporated areas; if it was not, the data collector was trained to delve further by asking
the customer's street name and consulting a list of street names in the incorporated areas in
order to make a final determination of whether that customer should be recorded as living
inside or outside the incorporated areas.
A second clarification question was asked of customers who reported having access to curbside
recycling. The survey asked the nature of their recycling container — whether they had an
orange bin or a blue rolling cart, and if a rolling cart, the color of its lid. Since the orange bins
are used only by the rural recycling program, this was an indicator that the customer likely did
*not* live inside town limits, and if this contradicted their earlier response, data collectors were
trained to use the street name method. Similarly, blue rolling carts used in the incorporated
areas have blue lids, while the newly distributed rolling carts in the rural areas have black lids,
and this distinction provided an additional check and opportunity for verification /clarification of
the customer's initial response.
Through these clarification questions and careful training of data collectors, OCSWM staff made
every effort to ensure that the final answer recorded on each survey form properly
characterized the customer's residence as being inside or outside the incorporated areas of the
county.
ADDITIONAL SURVEY TOPICS
The survey contained questions on three additional topics relevant to SWCC usage. Customers
who reported that they do not currently have access to curbside recycling services were asked
whether, if they had such service, they thought they would use it, and if not, why not.
Customers who reported having access to curbside recycling were asked whether they had
brought recycling to the SWCC that day, and if so, why. Finally, all customers were asked how
often they typically use any of the SWCCs.
SAMPLE DESIGN
The unit of analysis for this survey is the instance of use of a SWCC. The survey was designed to
estimate the proportion of usage (not users) of the SWCCs attributed to persons living inside
town limits and outside them. This proportion is inherently variable on any given day,
depending on which users happen to come to the SWCC that day. The survey was designed to
take a "snapshot" of the usage of each SWCC over a one week period. A one week period was
chosen for two primary reasons: usage rates vary by day of week (making one week the
shortest meaningful period), and the need to avoid undue burden on the public. Since the unit
of analysis was the instance of use, every time a customer entered the SWCC, that instance of
use was eligible for the survey. There could be no "skipping over" customers who already
responded to the survey, as this would bias the estimates of usage. OCSWM staff suspected
(and it is confirmed by the survey data), that most SWCC users come to the site once a week or
u
more. A data collection period longer than one week would result in a large number of
customers being asked to do the survey a second, third, or even fourth time. Cooperation rates
would be expected to be poor in such situations, which would lead to missing data that could
potentially bias the survey results. Further, given that most customers use the SWCC at least
once a week, no new information would likely have been gleaned by a longer data collection
period: in expectation, since most users come to the SWCC once a week or more, one week is
the same as any other week, provided no holidays or severe weather situations cause unusual
aberrations.
Having identified one week as the appropriate period of data collection, we turned our
attention to how customers would be selected for the survey. In order to make proper usage
estimates, we would either need to survey every single customer (infeasible given the large
numbers of customers entering the site in a very short period of time at some SWCCs, or we
needed a scientifically rigorous way to select customers —a random probability sample. In a
random probability sample, every element of the target population (instance of use of an
SWCC, in this case) must have a known probability of being selected into the sample. For the
SWCC survey, the way to implement this would be to "count cars" as customers entered the
site, and to systematically survey every "nth" customer. The "n" needed to be a number that
generated sufficient surveys for a reliable survey estimate, but also one that the data collection
staff could feasibly implement. We estimated that it would take 2 -3 minutes for the data
collector to follow a selected customer to their stopping point, wait for them to get out of the
vehicle, and then administer the survey. At some sites at some hours, several vehicles may
enter the SWCC during that 2 -3 minutes when one data collector was unavailable. Through
discussion with OCSWM staff, it was determined that data collection staff could reliably survey
every 51h customer at most SWCCs on most days. The exceptions were Eubanks Road and
Walnut Grove Church Road sites on the weekend days when these sites receive heavy usage.
For those sites on those days, a sampling rate of every 15th customer was planned. These
sampling ratios were expected to yield sufficient surveys for reliable estimation of the
parameters of interest.
DATA COLLECTION
OCSWM staff hired, trained and supervised the data collectors. Surveys were conducted at the
Eubanks Road and Walnut Grove Church Road SWCCs for the one -week period spanning
Thursday, January 22 to Tuesday, January 27, 2015. (All SWCCs are closed on Wednesdays).
Surveys were conducted at Ferguson Road, Bradshaw Quarry Road, and High Rock Road SWCCs
on Friday, January 30 through Sunday, February 1 and on Tuesday, February 3 —a period
encompassing all operating days in a one week period for these centers, since they are closed
on Mondays, Wednesdays and Thursdays.
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Paper surveys were used. When the data collector was unable to obtain a completed survey
from the sampled customer, he /she attempted to survey the next customer instead. Situations
requiring this type of substitution included customers who did not speak English, refused to
participate in the survey, or did not live in Orange County. Substitution was discouraged and
data collectors were trained to be persistent and try to get at least the key piece of information
from the sampled customer. A survey was deemed "complete enough" if the data collector
was able to ascertain whether or not the customer lives inside town limits; substitutes were not
sought in situations where this information was determined, even if the respondent was unable
or unwilling to answer the remainder of the survey questions. The number of substitutions at
all sites was low, ranging from 0 to a maximum of 3 per site per day.
In total, 1,335 surveys were completed during the 2 week data collection period. The number
of surveys completed at each site by day of week is shown in Table 1.
Table 1. Number of Surveys Completed by Site and Day
Monday Tuesday Thursday Friday Saturday Sunday Total
[dhoa Qu. 31 27 37 31 126
70 86 88 73 35 24 376
55 44 65 61 225
59 49 75 20 203
ve 76 92 86 83 38 30 405
146 323 174 276 250 166 1,335
OCSWM staff reviewed the survey forms and keyed the data into an online data entry program
provided by the Odum Institute. Only six forms had to be omitted due to data collector error
making it unclear whether the customer lived inside or outside town limits; all other forms
were of good quality.
WEIGHTING
Data collectors recorded the total number of customers who entered each site each day of data
collection. These totals allowed us to generate precise weights for each survey date and site.
The weight was generated simply by dividing the total number of uses for the day /site by the
number of surveys completed for that day /site. Due to good fidelity to prescribed data
collection procedures, the weights varied little from the expected values based on the sampling
design —that is, a weight of "5" for surveys at most days /sites and "15" for Eubanks Rd and
Walnut Grove Church Rd on Saturday and Sunday. One exception was that the Bradshaw
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Quarry Rd SWCC was intended to be sampled at a 1 in 5 rate on Sunday, but data collectors
mistakenly implemented a 1 in 15 procedure. Thus, fewer surveys were collected for Bradshaw
Quarry Rd on that date than were expected and we were required to use the higher weight for
that date /site.
Weight calculation and data analysis were conducted in SAS Version 9.3.
. 5 I&E
All results are weighted as described above. Appendix B provides 95% confidence intervals for
each estimate. Here we present point estimates.
IN /OUT OF TOWN LIMITS
Across all days and sites, 89% of SWCC uses during the data collection period were made by
customers who live outside town limits and 11% by customers residing within town limits.
Usage by individual SWCC is shown in Figure 1. Four of the sites were used almost exclusively
by residents outside town limits. Only the Eubanks Road site received more than 5% of its uses
by customers residing inside town limits.
100
90
80
70
60
50
40
30
20
10
0
Figure 1. Perecentage of Uses by Out of Town /In Town
Residents by SWCC
1.6 2.7 0.4 4.4
30.1
98.4 69.9
Bradshaw Eubanks
11.1
97.3 99.6 95.6 88.9
Ferguson
Outside Town Limits
High Rock Walnut Grove Total
In Town Limits
Most of the customers who reported living inside town limits reside in Chapel Hill. Chapel Hill
accounted for 54% of in town customers, while Carrboro accounted for 26% and Hillsborough
for 20 %. No customers reported being from the incorporated area of Mebane lying within
Orange County.
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CURBSIDE RECYCLING
Forty -eight percent of customers during the data collection reported having access to curbside
recycling services. Of these, 51% were nonetheless recycling at the SWCC the day they were
surveyed. When asked why, 66% said it was because they were coming to the SWCC anyway to
drop off trash or other items, 10% said it was because their recycling containers were full
before their curbside collection day, 1% said they missed their regular curbside collection day,
and 22% said they had "other" reasons. Almost all the "other" reasons reflected a stated or
implicit belief that the SWCC is more convenient, either because the customer has a long
driveway, finds it difficult to maneuver a rolling cart to their curb, or for some other unspecified
reason finds the SWCC more convenient.
Customers who reported not having access to curbside recycling were asked whether, if they
had it, they thought they would use it. Sixty -two percent said yes. The reasons given by those
who said they would not use it focused primarily on convenience —that they were coming to
the SWCC anyway to deposit trash, that they have a long driveway, that the SWCC is just "more
convenient" or they prefer to do it the way they always have.
FREQUENCY OF SWCC USE
Most surveyed customers (72 %) reported using a SWCC at least once a week. Figure 2 displays
responses for this item
Figure 2. Frequency of SWCC Use
45
40 39.2
35 32.4
30
25
20 15.9
15 12.5
10
5
0
Percentage of customers reporting...
More than once a week About once a week
About once every two weeks ■ Less than every two weeks
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The Orange County SWCC survey used rigorous statistical methods and accepted weighting and
analysis procedures to derive estimates of SWCC usage by customers residing inside and
outside town limits. In addition, it provided useful information about recycling habits and
preferences of Orange County residents. While these results accurately portray the nature of
SWCC usage during the January 22 — February 3, 2015 data collection period, readers are
cautioned that the survey provides a snapshot into this single period of time and should not be
treated as a forecast for the future. Many factors both within the SWCCs themselves and in the
environment they operate in could change usage patterns over time, such as influx and
geolocation of new residents and developments, changes to curbside recycling programs,
changes to operating hours or services available at the SWCCs, seasonal variations, or physical
improvements /modernization of the SWCC(s), to name just a few. Nonetheless, the "snapshot
in time" provided by this survey provides useful information to the County and the public as
they consider how future solid waste management plans may both impact and be impacted by
the SWCCs.
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Appendix A. Questionnaire
SOLID WASTE CONVENIENCE CENTER SURVEY
Center Location: Day of Week:
Date: Click # Initials:
1. Do you live within the town limits of one of the towns?
Yes 4 Which one? Carrboro Chapel Hill
No, outside town limits
Uncertain /Can't Determine 4 What street do you live on?
2. Do you have access to curbside recycling services?
YES
i
3. Do you have an orange bin or a blue rolling cart?
Orange bin (may have other color bins -just check orange)
Q1 should be "outside limits." If not, record street name.
Blue cart4Does it have a blue lid or black lid?
Blue lid (weekly collection)
Q1 should be "inside limits." If not,
record street name.
Black lid (every other week and NEW!)
Q1 should be "outside limits." If not,
record street name.
Neither or don't know type of container
4. Are you recycling here today?
Yes --) Since you have access to curbside recycling, why
did you bring recycling here?
Coming here anyway to drop off trash or
other items
Recycling containers were full before my
curbside collection day
Missed my regular curbside day
Other:
Not recycling today
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Hillsborough Mebane
NO because "outside town limits" in Q1
Continue with Q5 below. i
NO because in apartment. Skip to Q6 at bottom
5. If you had access to curbside recycling,
do you think you would use it
Yes 4Skip to Q6 at bottom
No4 Why not?
6. How often do you typically use any of the convenience centers? Is it...
More than once a week,
About once a week,
About every two weeks, or
Less than every two weeks?
Surveyor Notes:
CONTINUE WITH Q6
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Appendix B. Weighted point estimates with 95% confidence intervals
Confidence intervals are indicators of the precision of the survey estimates, taking into account
sampling and weighting. The confidence interval can be interpreted as "If we drew 100
independent samples of the target population, in expectation 95 times the result we would get
would be within this interval."
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Variable
Response
Percent
95% Confidence Interval
Do you live within the town limits of one of the
towns? (If Uncertain/Can't Determine is
marked,... (n =1335)
Yes
11.09 (9.36- 12.82)
No, outside town limits
88.91 (87.18- 90.64)
Do you live within the town limits of... (n =128)
Carrboro
25.70 (17.20- 34.21)
Chapel Hill
54.31 (45.59- 63.03)
Hillsborough
19.99 (15.94- 24.03)
Do you have access to curbside recycling
services? (n =1305)
Yes
47.61 (45.17 - 50.05)
No because outside town limits
51.20 (48.77 - 53.63)
No because in apartment
1.19 (0.49 -1.90)
Are you recycling here today? (n =600)
Yes
50.96 (47.00 - 54.91)
Not recycling today
49.04 (45.09 - 53.00)
Since you have access to curbside recycling,
why did you bring recycling here? (n =277)
Coming here anyway to drop off trash or other items
66.42 (60.36- 72.49)
Recycling containers were full before my curbside
collection day
9.89 (6.29- 13.50)
Missed my regular curbside day
1.47 (0.31 -2.63)
Other, specify:
22.21 (16.53- 27.90)
If you had access to curbside recycling, do you
think you would use it? (n =659)
Yes
62.02 (58.22- 65.82)
No
37.98 (34.18 - 41.78)
How often do you typically use any of the
convenience centers? Is it... (n =1317)
More than once a week
32.38 (29.85- 34.91)
About once a week
39.21 (36.44 - 41.99)
About once every two weeks
15.88 (13.74- 18.02)
Less than every two weeks
12.52 (10.67- 14.38)
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Center location
Response
Percent
95% Confidence Interval
Bradshaw Quarry
Yes
1.60 (0.00 -3.61)
Bradshaw Quarry
No, outside town limits
98.40 (96.39- 100.0)
Eubanks
Yes
30.14 (25.00- 35.28)
Eubanks
No, outside town limits
69.86 (64.72- 75.00)
Ferguson Rd
Yes
2.71 (0.78 -4.64)
Ferguson Rd
No, outside town limits
97.29 (95.36- 99.22)
High Rock Rd
Yes
0.41 (0.00 -1.12)
High Rock Rd
No, outside town limits
99.59 (98.88- 100.0)
Walnut Grove Ch Rd
Yes
4.44 (2.27 -6.60)
Walnut Grove Ch Rd
No, outside town limits
95.56 (93.40- 97.73)
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The Odum Institute for Research in Social Science was founded in 1924 by
Howard Washington Odum, making it the oldest university -based
interdisciplinary social science research institute in the United States. We
provide education, training, data collection, and archive services to
researchers both within and beyond UNC— Chapel Hill. Our mission is to
facilitate scientifically rigorous social science research that contributes to
better lives for the citizens of North Carolina and the world.
This report was prepared by Teresa Edwards, Odum
Institute Assistant Director for Survey Research
Teresa—Edwards@unc.edu
February 25, 2015
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