 |
Evaluation of the Effectiveness
of Pollution Prevention Planning in NJ
III. Study Methodology
Before developing its questionnaire and interview structure,
HRA accompanied NJDEP on a site visit and examined a few plans
submitted to NJDEP. The site visit demonstrated that HRA would
have to examine the plans of all the facilities it selected
to survey. Since only plan summaries are submitted to NJDEP
and plans are kept on site at the facility, HRA could not
determine if the facilities' plans contained the elements
it would be asking facilities to comment on unless the plans
themselves were reviewed. Also, placing planning activities
in light of previous activities at facilities was virtually
impossible without site visits.
| Box
2. Plan Completeness Groups
A (29 facilities, 25 percent of total)
- All applicable process-level inventory data (A)
- Some cost in both Part I and Part II (A,P)
- Options listed beyond those implemented (P)
- Use and /or NPO five year goals (A)
B (22 facilities, 19 percent of total)
- All applicable process-level inventory data (A)
- EITHER some Part I or Part II costs (A,P) and no
options
- beyond those implemented (P)
- Or No costs at all (A,P) and options listed beyond
- Those implemented (P)
- Use and/or NPO five-year goals (A)
C (9 facilities, 8 percent of total)
- All applicable process-level inventory data (A)
- No cost data (A,P)
- No options beyond those implemented (P)
- May have some goal data (A)
D (55 facilities, 46 percent of total)
- No process-level inventory data (A)
- May have some data cost (A,P), options (P), and
goals (A)
KEY
A =Attribute found in the Administrative Review
(see Appendix B)
P =Attribute found in the Plan Quality review (see Appendix
C) |
III. A. Facility Selection
NJDEP provided HRA with a database of 552 facilities that
either had submitted a plan summary to NJDEP by July 1, 1994,
or were considered to be covered by the planning requirements,
based on their 1992 DEQ-114 data. Each facility was assigned
a random number from zero to nine, and NJDEP itself visited
a random selection of facilities with numbers seven through
nine. HRA used the remaining 407 facilities as a basis for
selection.
HRA had two considerations in selecting facilities. First,
to gauge the effectiveness of planning, it was important to
examine as much of the generation of nonproduct output (NPO)
as possible, while maintaining representation of the range
of facility sizes. Accordingly, facilities selected for HRA's
study had to have generated a substantial fraction of New
Jersey's total NPO in 1992, the year of the latest DEQ-114
data available at the time HRA selected facilities. Second,
to avoid artificially inflating the impact of a particular
industry, the distribution of industries had to represent
the distribution of industries among facilities available
for visits and those submitting plans.
The 1992 DEQ-114 data for the 407 facilities available to
HRA showed a high concentration of NPO generation at a relatively
small number of facilities: 39 facilities generated at least
2.0 million pounds of NPO in 1992. The remaining 368 facilities
each generated less than 2.0 million pounds of NPO in 1992,
and only six of them generated between 1.0 and 2.0 million
pounds. HRA selected the top 25 facilities for 1992 NPO generation
and selected another 25 at random from facilities generating
less than 2.0 million pounds of NPO in 1992. Some of the facilities
had either closed or dropped below reporting thresholds for
1993 and were not required to submit plan summaries; others
were participating in NJDEP's facility-wide permitting program
and were receiving NJDEP's assistance in preparing their plans.
Therefore, 15 additional facilities were selected at random
as alternates from the group generating less than 2.0 million
pounds. HRA scheduled a total of 48 site visits: 21 (44 percent)
among those generating more than 2.0 million pounds of NPO
and 27 (46 percent) chosen at random among the facilities
generating less than 2.0 million pounds of NPO. This selection
of facilities covered 66% of the 1992 NPO generated by facilities
available to HRA (see Table 1).
HRA visited facilities in each of the five industrial classifications
required to submit plans by July 1, 1994 (SIC codes 26, 28,
30, 33, and 34). The selection of large facilities and random
selection of other facilities resulted in a distribution of
facility SIC codes that reasonably mirrors the industrial
distribution of facilities available for visiting and thus
validated the sample as representative. In addition, HRA visited
one facility reporting under SIC code 20 and one under 35
(Food and Electrical, respectively) that submitted plans to
NJDEP before their deadline of July 1, 1996 (see Table 2).
III. B. Protocol for Facility Visits
HRA staff met with facility representatives, usually with
the person in charge of preparing the plan. Other facility
employees who participated in the planning process were usually
present for all or part of the visit. In facilities that had
plans prepared by outside consultants, the consultant was
usually present as well. In a few cases, the person in charge
of preparing the plan was no longer employed at the facility
and was unavailable for discussion. Visits typically followed
a set protocol:
- HRA began each visit by explaining the purpose of the
visit and by assuring each facility of the confidential
nature of the visit: no information about specific facilities
would be shared with NJDEP or others.
- The discussions began with the HRA questionnaire containing
a series of questions designed to place creation of the
facility's plan in a historical context of planning and
general environmental activities at each facility. These
were followed by questions about creation of the plan and
a series of questions about the planning process, following
an outline derived from Industrial Pollution Prevention
Planning: Meeting Requirements under the New Jersey Pollution
Prevention Act (see Appendix A).
- HRA then examined the facility's plan and environmental
reporting data (DEQ-114, TRI Form R, and New Jersey Hazardous
Waste Generator forms) and completed two questionnaires
developed by NJDEP: an Administrative Review and a Plan
Quality Review. The Administrative Review steps through
the provisions of the planning rule and measures completeness
of the plan. The Plan Quality Review expands on the Administrative
Review to indicate individual features of facility's plan.
- After completing the review of the plan, HRA met with
the facility representatives again to discuss the results
of the Administrative and Plan Quality Reviews. The facility
was offered a photocopy of each review. Most visits ended
with a tour of the facility.
| Box
3. Plan Quality Groups
Source Group
- All sources are identified for each process
- Facility did not provide more detail on sources
in targeted processes than non-targeted processes
- Sources are not grouped across process boundaries
- Source-level NPO sums to process-level NPO
Process Group
- Materials accounting was done for each targeted
process
- The materials accounting balances (or the plan explains
differences)
- Process-level use sums to facility-level use (or
the plan explains differences)
- Intermediate products are tracked correctly
- Coproducts are tracked correctly
Part I Cost Group
- Costs are estimated for some or all Part I cost
categories listed in the Plan Quality Review
Targeting Group
- Targeting did not prevent selection of "important"
processes
- Facility did not "target out" processes
- Facility did not target processes with less significant
amounts of NPO
Options Group
- The option list is a good faith effort to identify
options
- Options match the list of sources of NPO
- Facility analyzed technical feasibility for each
option
Part II Costs Group
- Facility analyzed financial feasibility for each
option
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III. C. General Analysis
HRA used data from the Administrative Review, the Plan Quality
Review, the HRA questionnaire, plan summary forms, TRI Form
R, and DEQ-114 reports for each facility to assemble a list
of factors such as plan attributes, reactions of facilities
to the planning process, types of previous environmental and
planning activities for the facilities, and projected reductions
in use and NPO. These factors were analyzed against four measures
of effectiveness: plan completeness, plan quality, percent
reduction goals for use, and percent reduction goals for NPO.
(Box 1, in the Introduction, lists factors and measures; Section
III discusses plan completeness and plan quality). The goal
of these analyses was to determine if any of the factors was
associated with more complete plans, better plans, or higher
percent reduction goals. Given the complexity and individuality
of facilities' plans, HRA decided it was appropriate to use
percent reduction goals both as measures and as factors against
measures of plan completeness and plan quality. They were
not used, however, as both factors and measures in any one
analysis.
HRA tested factors against measures for statistical significance
using a standard chi-squared 95% confidence interval test.
Not all facilities could be used in each analysis, and tables
list the facility counts and reasons for excluding one or
more of the facilities. For example, when using percent reduction
goals as measures, one facility had to be excluded because
it represented 40 percent of the NPO for the State of New
Jersey in 1993, and whatever reduction goals it set virtually
dictated the results for the particular group it happened
to be in. HRA also excluded from analyses involving reduction
goals those chemical forms with inconsistent goals, i.e.,
when a facility's stated goal of pounds of NPO to be reduced
over five years for a particular chemical was inconsistent
with the base year pounds on the DEQ-114 and had not been
clarified during the site visit. If all of a facility's goals
were inconsistent, the facility was excluded from the analysis.
III.C.1. Measurement of Plan Completeness
HRA selected four categories as a measure of plan completeness:
- Process-level inventory
- Part I and Part II costs
- Pollution prevention reduction options beyond those to
be implemented
- Five-year use and NPO reduction goals, both facility-wide
and per unit product
Facilities were assigned to one of four groups based on data
from the Administrative and Plan Quality Reviews. These four
groups essentially rank plans from most to least complete
(see Box 2), and a facility in either of the top two groups
would be considered to have a more complete plan than a facility
in either of the bottom two groups.
| Box
4. Plan Quality Elements
- Facility Totals -- |
| Number
of Elements |
Number
of Facilities |
Percent
of Total (115) |
| 0
Elements |
2
|
1.7
|
| 1
Elements |
26
|
22.7
|
| 2
Elements |
24
|
20.8
|
| 3
Elements |
21
|
18.3
|
| 4
Elements |
24
|
20.8
|
| 5
Elements |
16
|
14.0
|
| 6
Elements |
2
|
1.7
|
|
III.C.2. Measurement of Plan Quality
HRA examined the Plan Quality Review forms to determine
measurements of plan quality. Like the Administrative Review,
the Plan Quality Review lists attributes of plans, but these
attributes address issues such as thoroughness, good faith
effort, and understanding of facility activities, the planning
process, and pollution prevention (see Appendix C). HRA devised
six groups of questions from the Plan Quality Review: Sources,
Processes, Part I Costs, Targeting, Options, and Part II Costs
(see Boxes 3 and 4). HRA then examined the Plan Quality Reviews
to see if facilities had the appropriate responses to all
questions in each group. Facilities received a "1"
for each group completed with all the appropriate responses.
An inappropriate answer to any question in the group resulted
in zero credit for that group. Thus, facilities could earn
plan quality totals from zero to six with a "better"
plan having a higher number.
III.C.3. Plan Completeness versus Plan Quality
At first glance, the plan completeness and plan quality
criteria seem similar enough to justify having one measure
instead of two. However, the plan quality criteria have more
specific judgment attached to them, not just "was it
there", but "how well was it done?" That is,
inputs and outputs should balance, targeting choices should
not exclude important processes, etc. Although the plans with
the highest possible quality score are also in the top completeness
group, the two measures do not track exactly with one another.
It is possible to have a reasonably complete plan that is
not very good, for example. Although the two measures do overlap
somewhat, HRA developed them separately to include as much
data collected during site visits as possible.
| Box
5. Number of Facilities Used in Correlation Analyses
|
| Number
of Facilities Used |
| Factor
|
N
|
U
|
C
|
Q
|
Reasons
for Exclusion |
| Previous Source
reduction, |
103 |
103 |
115 |
115 |
1,2
|
| Targeting, |
(32) |
(43) |
(48) |
(48) |
|
| Attributing NPO
to sources, |
|
|
|
|
|
| Amount of NPO generated,
|
|
|
|
|
|
| NPO/use ratio, |
|
|
|
|
|
| Finding planning
worthwhile. |
|
|
|
|
|
| NPO per unit product
|
95 |
95 |
107 |
107 |
1,2,3
|
| Calculated before
planning. |
(43) |
(43) |
(48) |
(48) |
|
| Composition of planning
|
93 |
93 |
104 |
104 |
1,2,4
|
| team. |
(43) |
(43) |
(48) |
(48) |
|
| Part I costs calculated.
|
103 |
103 |
n/a |
n/a |
1,2,5,6
|
| |
(43) |
(43) |
|
|
|
| Additional costs
calculated. |
36 |
36 |
39 |
n/a |
1,2,5,6
|
| |
(11) |
(11) |
(11) |
|
|
| Percent NPO reduction
goal, |
n/a |
n/a |
103 |
103 |
1,2
|
| Percent use reduction
goal. |
|
|
(43) |
(43) |
|
| Environmental costs
included |
(43) |
(43) |
(48) |
(48) |
1,2
|
| in previous reviews,
|
|
|
|
|
|
| Former facility-wide
plan, |
|
|
|
|
|
| Former formal planning,
|
|
|
|
|
|
| Options identified
through planning, |
|
|
|
|
|
| Parent company.
|
|
|
|
|
|
(Numbers in parentheses for facilities visited by HRA)
Key
- Facilities had no consistent reduction goals
- One facility represented 40% of NPO totals
- Unsure if NPO per unit product had been previously
calculated
- Unknown planning team composition
- Costs part of criteria for completeness and/or
quality
- Only facilities with Part I costs included
N = Percent NPO reduction goal
C = Plan completeness
U = Percent use reduction goal
Q = Plan quality |
III.C.4. Measurement of Reduction Goals
Facilities must report facility-wide, five-year reduction
goals for use and NPO for each reportable hazardous substance.
HRA compared these goals - pound and percent reduction - to
the facilities' 1993 DEQ-114 data for consistency. For example,
a facility projecting a 30 percent reduction in NPO of dichloromethane
in its pollution prevention plan should have listed on its
plan summary an amount of reduction in pounds equal to 30
percent of the dichloromethane NPO it reported on its DEQ-114
form for that chemical. Discrepancies arise for two reasons:
Either the facility could have had different base-year NPO
totals in its plan than it reported on the DEQ-114, or there
was an error in calculating pounds or percent reduction. HRA
and NJDEP were usually able to resolve these discrepancies
in their site visits or by telephone. When discrepancies could
not be resolved, HRA dropped from its analysis those individual
chemical goals that were inconsistent. In some cases, this
meant dropping an entire facility from a particular analysis.
In addition, one facility reported 1993 NPO amounts and reduction
goals high enough to overwhelm any analysis using reduction
goals as a measure. This facility was not included in such
analyses. Tables of analyses using reduction goals as factors
list the number of facilities included and reasons for any
exclusions, and Box 5 lists the number of facilities included
in all analyses.
III.C.5. Reduction Projections on 1991 and 1992 DEQ-114
Forms
New Jersey facilities have been required to make two-
and five-year projections for decreases in NPO due to source
reduction on their DEQ-114 forms each year since 1988. HRA
examined five-year projections made on facilities' 1991 and
1992 DEQ-114 forms and compared them to projections reported
on their plan summaries, both for the 115 facilities visited
by HRA and NJDEP and the 405 facilities that submitted plan
summaries to NJDEP by July 1, 1994.
Facilities made chemical-specific reduction projections on
their DEQ-114 forms, and HRA first examined the projections
for consistency. Some projected five-year reductions were
greater than the base-year NPO total for that chemical; these
were discarded. HRA also discovered that the DEQ-114 forms
and instructions gave conflicting directions for calculating
projections: The forms indicated that projections were to
be reported on a per-year basis, while the instructions asked
for the total amount to be reduced in two or five years. It
was impossible to determine if the five-year projections were
the total amount to be reduced or the total reduction divided
by five. To have a basis for comparing these projections,
made before pollution prevention planning, with reduction
goals set in the plan summaries, HRA devised a lower- and
upper-bound strategy to calculate the earlier projections.
HRA took the five-year reduction projection as stated on
the 1991 and 1992 DEQ-114 forms to be the lower bound (as
long as it was lower than the base-year NPO amount; otherwise,
the upper and lower bound were zero). If the five-year projection
could be multiplied by five and still remain lower than the
base-year NPO amount, that multiple became the upper bound.
If the multiplication put the figure higher than the base-year
NPO, then the non-multiplied figure served as the upper bound
(in other words, the lower and upper bound were the same).
Consistency problems occurred when facilities submitting
plan summaries did not submit 1991 or 1992 DEQ-114 forms and
when a valid NPO amount could not be calculated for 1991 or
1992. Consistency was also a problem for the plan summaries.
HRA checked the chemical-specific NPO reduction goals in plan
summaries for consistency against the facilities' 1993 DEQ-114
forms. First, the reduction goal in pounds was divided by
the percent reduction goal; the result should have equaled
the 1993 NPO for that chemical as reported on the DEQ-114.
Inconsistent data for facilities that were visited by HRA
and NJDEP had already been corrected, if possible. Of the
115 facilities visited, HRA included 86 to 97 in each analysis,
depending on whether 1991 or 1992 projections were used. Inconsistent
data for any of the 296 facilities that were not visited could
not be checked with the facilities, so HRA applied a +/- 10%
consistency rule: As long as the data matched within 10% the
goal was retained. In analyzing all plan summaries, HRA included
262 to 307 facilities in each analysis, depending on whether
1991 or 1992 projections were used.
III.C.6. Analysis of Previous Environmental Activities
and Facility PerceptionsHRA developed a questionnaire
to establish the pollution prevention history of each facility,
as well as to determine how facility representatives perceived
the planning process. Structured interviews were undertaken.
Interviewers used the same list of questions for each facility,
with freedom to vary the order in which they were asked. Interviewers
had studied reporting forms and pollution prevention plans,
when available, and were thus sensitive to inconsistencies
and omissions of data that required further questioning to
clarify. Open-ended questions gave respondents a great deal
of liberty to elaborate. After the interviews, HRA developed
a coding format for analyzing responses.
When possible, HRA interviewed the facility employee or consultant
who had actually prepared the pollution prevention plan. In
a few cases this was impossible because that person was no
longer employed at the facility or employed as a consultant.
It is important to note that responses to interview questions
are self-reported and cannot be verified. Nonetheless, survey
responses provide valuable information on facilities' perceptions
of their activities which serves as an important counterpoint
to information obtained via reporting.
III.D. State and Federal Data Used in the
Evaluation
DEQ-114: New Jersey's
DEQ-114 database contains chemical- and facility-specific
materials accounting, NPO generation, releases and transfers,
and source reduction data. Facilities in New Jersey have reported
annually since 1987. DEQ-114 is the only database in the United
States that contains data on amounts of NPO not generated
due to source reduction. In addition, facilities are required
to estimate amounts of NPO that will not be generated due
to source reduction in two years and five years following
the reporting year.
HRA used DEQ-114 data in three specific ways for this report:
- Verifying that facility-wide NPO totals in facilities'
plans were consistent with data reported on the 1993 DEQ-114.
- Verifying that facility-wide NPO and use reduction goals
listed in the plan summary were consistent; that is, that
the reduction goal, in pounds and percent, was consistent
with the base year NPO amounts reported on the 1993 DEQ-114.
- The projections of NPO to be reduced by source reduction
in five years reported in previous years on the 1991 and
1992 DEQ-114 forms were used to compare with facility-wide
reduction goals reported in plan summaries. This comparison
attempts to show the influence of the planning process on
setting goals.
Although the DEQ-114 data are unique and valuable, they also
have limitations:
1.) Materials accounting data are not
always consistent. The amount of NPO calculated from
the materials accounting inputs and outputs should in most
cases equal the sum of the releases and transfers on the DEQ-114
forms. In other words, for each chemical:
| Amount in starting inventory
+ Amount brought on site
- Amount consumed on site
- Amount shipped in product
- Amount in ending inventory |
should equal |
Point source air emissions
+ Fugitive air emissions
+ Surface water discharges
+ Underground injection
+ Releases to land
+ Off-site transfers to recycling, energy recovery,
treatment, and disposal
+ Amount destroyed through on-site treatment
+ Amojnt sent to Publicly Owned Treatment Works |
In practice, this does not always occur, either due to roundoff
or errors in facility reporting. In some cases, NPO calculated
by materials accounting is less than zero, so NPO for these
analyses was calculated using releases and transfers.
2) Source reduction is probably underreported
both in the amounts reduced and projections for amounts to
be reduced over five years. HRA examined source reduction
activities undertaken by facilities as reported on the DEQ-114,
U.S. TRI Form R, and New Jersey Pollution Prevention Plan
Summary forms. HRA also asked facilities if they had undertaken
source reduction activities. While 60 percent of facilities
reported prior source reduction on state and federal forms,
83 percent told HRA that they had undertaken source reduction
prior to planning. Facilities described these activities and
HRA verified that they were indeed source reduction. Other
studies have confirmed that facilities do not always consider
appropriate reduction projects to be source reduction, especially
when the result was unintentional. Thus, when facilities made
five-year projections for amounts of NPO to be reduced by
source reduction, it is possible that they were not considering
all of the effects of projects under development. Nonetheless,
these data are a source of projections for NPO reduction by
pollution prevention not found in any other U.S. database.
3) Some projections for amounts
of source reduction may actually be use reduction projections.
HRA considered facilities' source reduction projections to
be NPO reductions, as described above. The instructions for
DEQ-114 forms give facilities the opportunity to make either
NPO or use reduction projections, although facilities do not
have to specify whether the reduction projections are for
NPO or use. After consultation with NJDEP, HRA decided to
treat all reduction projections as NPO reductions for three
reasons: (a) Total use calculations are not required on the
DEQ-114 forms; (b) although facilities were required to calculate
use in their pollution prevention plans, many of them did
not, suggesting that they do not typically calculate use and
so would not make use reduction projections; (c) facilities'
use reduction goals in their plan summaries were often calculated
incorrectly (see Plan Summary data, below).
U.S. Toxics Release Inventory (TRI)
Form R: TRI is a facility- and chemical-specific system
for reporting on chemicals at industrial facilities in the
United States. Since 1987, facilities have reported amounts
of releases and off-site transfers to U.S. EPA. On-site waste
management activities and amounts were added with the 1991
reporting year, along with source reduction activities undertaken
during the year (although not amounts of waste reduced due
to source reduction). Facilities also estimate amounts of
on-site waste management, off-site transfers, and releases
plus transfers to disposal for two years following the reporting
year.
HRA used TRI data in two ways for this evaluation:
- Comparing amounts of NPO listed in facility pollution
prevention plans with amounts of NPO listed in the 1993
DEQ-114 forms and 1993 TRI Form Rs. NPO is called "production-related
waste" in TRI and is calculated by summing the data
in Sections 8.1-8.7 (on-site waste management plus off-site
transfers of waste plus on-site releases and transfers to
disposal). This total should equal the NPO amounts on the
DEQ-114 forms, which in turn should be the amount of base-year
NPO listed in the pollution prevention plan. Forty-eight
percent of facilities visited by HRA and NJDEP had DEQ-114
or TRI data that needed to be revised due to this comparison
or the planning process.
- Examining reporting of source reduction activities in
1991, 1992, or 1993. These data were used to determine if
facilities had undertaken source reduction prior to planning.
As with DEQ-114 data, source reduction is probably underreported
in TRI. Another issue concerning TRI data was whether or not
projections for production-related waste could be used to
compare goals made before New Jersey planning was required.
Since facilities project amounts of waste generation, it might
seem logical to compare these projections made in 1991 and
1992 with goals in the plan summary. However, changes in production-related
waste can occur for many reasons other than source reduction,
such as changes in production or changing calculation methods,
so HRA chose to use the source reduction projections from
facilities' DEQ-114 forms instead.
New Jersey Pollution Prevention Plan
Summaries: As part of the planning requirement, facilities
submitted summaries of their plans to DEP on standard forms
(see Section IV for some of the data elements required in
plan summaries). These summaries contain chemical-specific,
facility-wide reduction goals in use and NPO (both pounds
and percent), process descriptions, and percent reduction
goals for processes targeted for reduction. Facilities may
also describe pollution prevention activities since 1987 that
led to reductions in use or NPO.
HRA used the plan summary data in three ways for this report:
- Facility-wide goals for use and NPO were used as measures
to evaluate planning factors as described in Box 1.
- Voluntary information on source reduction activities
prior to planning was used to determine if facilities had
done source reduction before planning was required.
- Facility-wide goals for use and NPO were compared to
source reduction projections made on facility DEQ-114 forms
to determine if facilities made greater percent reduction
goals through planning than they had before.
Although plan summary data are a valuable resource, not only
for evaluation purposes, but for individuals interested in
learning about pollution prevention activities at local facilities,
the data have two important limitations:
- Goals are sometimes inconsistent
with base-year data. Data consistency was an issue
with plan summaries as with DEQ-114 data. Facility-wide
reduction goals in pounds were not always equal to those
calculated using 1993 DEQ-114 data and the percent reduction
goal. HRA and NJDEP attempted to reconcile these discrepancies
by contacting facilities; where they could not be resolved,
the reduction goal for that specific chemical was not used.
- Facilities did not always calculate
use reduction goals according to New Jersey's guidelines.
Since NPO is a component of use, numerical reduction goals
for NPO should not be greater than those for use. According
to definitions in the New Jersey guidance document, facilities
should assume constant production levels when calculating
NPO and use reduction goals, so NPO reduction amounts should
not be greater than use reduction amounts. HRA found that
some facilities were not assuming constant production, but
rather that the amount of production would increase because
of the decrease in NPO, so some numerical use reduction
goals were smaller than NPO reduction goals. HRA did not
revise use reduction goals unless they were inconsistent
with base year use amounts calculated from 1993 DEQ-114
data.
III.E. Statistical Method
A statistical test was performed to determine whether factors
of the planning process were associated with different levels
of plan completeness, plan quality or percent reduction goals.
That is, HRA tested whether some factors (for example, prior
source reduction activity) are present, on average, at plants
with more complete/better plans than at those without complete
plans. The possibility of correlation or association between
each program feature and the percent reduction goals or plan
characteristics was tested using a contingency analysis and
the Chi-squared test for independence.
The analysis identified whether the difference in reduction
goal, for example, between the number of facilities having
a different level of the program feature (such as those reporting
prior source reduction and those not reporting prior source
reduction) was statistically significant at the 95 percent
confidence level. In other words, it determined whether, 95
times out of 100, the same variation would not have occurred
in a hypothetical set of plants with just normal variation
and no association between the factor and the goals or plan
characteristic.
The Chi-squared test was applied to each pair of program
feature and plan characteristic or reduction goal. If the
difference between each pair and the hypothetical set of plants
was small (as measured against the Chi-squared statistic at
the 95 percent confidence level), then the pair is considered
statistically independent. If the difference is large, the
two features are not independent and may be associated at
the plants in the study.
It is important to note that the Chi-squared test only shows
whether, on average, a program feature tended to occur with
the level of plan completeness or reduction goal; it does
not show cause and effect. For example, even though plants
with greater amounts of NPO were associated with higher percentage
use reduction goals, how much larger percentage use reduction
goals would be expected to be with larger amounts of NPO are
not shown by this test.
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