Waste Minimization Practices by Waste Streams specific SIC Code 1. Introduction

Not only is it helpful do make some observations on the distribution of total numbers of waste minimization practices by waste stream but it is particularly interesting to look at the distribution of waste minimization practices by SIC codes that characterize the main manufacturing activity of companies. Taking the process-syecific SIC codes25 reported by the sample group, a series of tables were developed which give some insights into which industry groups seem to have

implemented relatively more waste minimization practices and which ones seem to have been rather reluctant in implementing waste minimization practices.

The previous analysis focused on the distribution of waste minimization practices either by company or by waste stream not differentiating among various industrial groups (characterized by SIC codes). In order to draw conclusions on possible production processes or industries where the proliferation of waste minimization might be particularly of interest, the distribution of waste minimization practices mentioned with each of the 553 waste streams is analyzed among the various industrial groups.

Two criteria can be used to analyses the distribution of waste minimization practices by industrial groups based on waste streams from the data of the National Generator Survey:

(i) waste minimization ratio26 (ii) waste minimization percentage27

25 Note that process-specific SIC codes are given for each process that generated a waste stream. In some cases, the process-specific SIC code differed from the primary SIC code given by the companies. See chapter 4.1.1. for further explanations.

26 The waste minimization ratio (WMR) is defined as the ratio of the number of waste streams per SIC code where waste minimization practices were implemented (# WS with WM) in a specific time period and the number of waste streams reported under this respective SIC code (total # WS).

As a formula : WMR = (# WS with WM) / (total i4_WS) ; based on

one

specific SIC code.

If the waste minimization ratio is 'one' for a certain industrial group (characterized by SIC code), this indicates that waste minimization practices have been implemented for all waste streams reported under this SIC code. All numbers smaller than 'one' indicate that waste minimization practices were not implemented at all waste streams reported under a certain SIC code.

27 The waste minimization percentage (WMP) describes the frequency at which a certain waste minimization practice is reported under a specific SIC code. It is based on the number of waste streams reported under this SIC code and thus takes into account that multiple answers could be given regarding various waste minimization practices implemented at one waste stream. The waste minimization percentage is defined as the number of waste minimization practices rjvMprac) mentioned at aIl waste streams ( W S ) under a certain SIC code (# WMPrac at WS) divided by the total number of waste streams reported under this SIC code (total # WS).

As a formulq: WMP [%I = [ (# WMPrac at WS) / (total # WS) I x 100%

Comparisons of the industrial groups of the sample size can be made in respect to those two criteria. Note that this analysis only uses the general descriptions of waste minimization practices referred to in chapter 7.6.1. and that multiple answers could be given.

Note that the waste minimization ratio and the waste minimization percentage are only nominal figures to describe the implementation of waste minimization. They are not necessarily quality criteria made to measure success in waste minimization. This is due to several reasons: (i) number and tme of waste minimization mactice(s1: the waste minimization ratio or percentage does not indicate how many and what kind of waste minimization practices were implemented at

one

specific waste stream, (ii) depree of pollution prevented: a lower waste minimization ratio or percentage at a certain SIC code might actually have been more beneficial to the environment as more pollution might have been prevented than at a higher waste minimization ratio or percentage, (iii) level of caDital investment: a lower waste minimization ratio or percentage at a certain SIC code might actually have resulted in a higher nominal investment in waste minimization technologies than a higher waste minimization ratio or percentage, and (iv) process independence: The waste minimization ratio or percentage does not correlate the waste minimization practice(s) implemented to the specific process at which the practice was applied in order to evaluate the technological change that was conducted. Despite these limitations of the two criteria used for the analysis of waste minimization practices among the sample group, figures on the basis of both criteria are an important means to indicate target groups for further scrutiny.

Companies were also required to describe the waste minimization practice(s) implemented at each waste stream with their own words (see GB 34 and GB 4028 )

.

It would be interesting to compare the descriptions of implemented waste minimization practices under each SIC code with the waste minimization percentage determined for each SIC code. However, the description of waste minimization practices is fairly scarce and does not seem to represent the practices actually implemented. This is due to various reasons: (i) several companies repeated the general waste minimization practices; (ii) other times, companies simply did not fill out the available answering space for the further description. In numbers, only for 112 of the 207 waste streams at which waste minimization practices were reported to have been implemented did companies actually describe waste minimization practices using their own description (for time prior to '86). For the time during '86, companies further described the waste minimization practices at a total of 127 waste streams out of 177 waste streams at which waste minimization practices were reported to have been implemented (see Table 9). Therefore, the grouping of reported descriptions of waste minimization practices gives some idea about the kind of waste minimization practices implemented but does not seem to present a complete picture of all waste minimization practices.

28 This refers to question GB 34 and question GB 40 which can be found in the second questionnaire

"Hazardous Waste Characterization". The following question was asked:" Describe the waste minimization practices that were imglemented PRIOR to 1986 for this hazardous waste." (GB 34) and "Describe the waste

m ~ t

these practices had on the volume generated and toxicitv of this hazardous waste. Indicate if changes in product production account for changes in waste volume." (GB 40)

Table 9: Distribution of

the

Frequency at which Descriptions of Implemented

Waste Minimization

Practices vere Reported prior to '86 ami during '86

on

C o m p t y Basis

vhere QiW practices were implemented BUT activities. They are: "Equipment Modification", "Process Modification", "Reformulation of Product", "Raw Material

Subsitution", "Better Housekeeping", "Waste Stream Segregation",

"Onsi% Recyclmg", and "Offsite Recycling".

7.9.2. Analysis of Waste Minimization Practices bv Waste Minimization Ratio (i) Introduction

To come up with a distribution of waste minimization ratios for the two time periods described in Table 10, the number of waste streams reported under the same two-digit SIC code were counted. After this, all those waste streams were counted (for each time period separately) at which waste minimization practices were reported to have been implemented at the same two-digit SIC codes. From those two sets of data, the waste minimization ratio was calculated according to the formula in footnote 26. The analysis was conducted with 13 different SIC codes covering 121 of the total 129 companies of the sample group. Six companies were not included in this particular

analysis as they only generated 12 waste streams representing 0.1% of the hazardous waste generated by the sample group. In addition those companies did not report processes which tend to have a high waste minimization potential such as for example "lab analysis", "R&D activities", or "repackaging of solvents" (see Appendix 3). Note that companies were asked to group their waste minimization practices under the waste m i n i ~ z a t i o n categories mentioned in chapter 7.6.1.

and that multiple answers could be given.

Table 10: Distribution of Waste Minimization Ratio'prior to ' 86 and during=

If the weste "ization ratio is one for a certajn industrial group {characterized by SIC code), this indicates that wesb minimization practices have been implemented at all waste smams reported under this SIC code.

AU wte" i z a t i o n ratios s-r than 'one' indicate ^that ~ 8 9 % ~ "jz ation p w t k e s were not implemented at all waste streams reported under a certain SIC code.

I

^'The full description of this SIC code is as follow: Electrical & Electronical Machinery, Equipment, and Supplies

I

Table 10 also presents the numbers necessary to calculate the waste minimization ratio which also give a good idea of the actual distribution by numbers of waste streams and waste minimization practices implemented under each SIC code. Moreover, the hazardous waste generated by SIC code is added to the exhibit for convenience and comparison.

(ii) Time Period prior to '86

Looking at Table 10 the waste minimization ratio for the time period Drior to '86 varies from "1"

to "0.1" among the 13 SIC codes included in the analysis. The hiyhest waste minimization ratio of

"1" can be observed with the industry group "Textile Mill Products" (SIC 22) followed by the industry groups "Stone, Clay, and Glass Products" (SIC 32) and "Primary Metals Industry" (SIC 33) with a waste minimization ratio of "0.8" and "0.7". Note that those industrial groups were only represented by two to four companies per each SIC code (see Fig.2). However, the amount of hazardous waste generated in 1986 by the companies under each of those SIC code lies between 167,695 lbs (SIC 22), 222,885 lbs (SIC 32), and 4,591,588 lbs (SIC 33). This comes up to a total of 0.3% of the hazardous waste generated by the sample group.

The lowest waste minimization ratio can be observed with the industrial group "Rubber & Plastics Products" (SIC 30) at "0.1" and with "Chemical Products" (SIC 28) and "Instruments" (SIC 38) both at "0.2". The industrial group "Chemical Products" constitutes 19% of all companies of the sample group (or 25 companies) and generated 1,296,582,112 lbs (or 78%) of the hazardous waste of the sample group, "Rubber & Plastics Products" is represented by three companies generating 361,186 lbs of the hazardous waste and companies with the SIC code "Instruments"

generated 557,949 Ibs. These two industrial groups represented 0.1% of the hazardous waste generated by the sample group.

Most of the industrial groups show a waste minimization ratio between "0.3" and "0.5" with the industrial group "Electrical and Electronic Machinery, Equipment, and Supplies" (SIC 36) being particularly interesting as they compose 17% of all companies of the sample group and 25% of all waste streams and show a waste minimization ratio of "0.5". This industrial group has also reported the largest number of waste minimization practices implemented for all waste streams mentioned.

(iii) Time Period during '86

Table 10 also depicts the waste minimization ratio of industrial groups for the time period during

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'86. The ratio varies between "0.7" to "0.2". The two industrial groups with the highest waste minimization ratio are "Stone, Clay, and Glass Products" (SIC 32) with a "0.7" ratio and "Lumber and Wood Products" (SIC 24) with a "0.6" ratio. These industrial groups are each represented by only two companies of the sample size. The hazardous waste those companies contribute,

however, come up to 222,885 Ibs (SIC 32) and 193,768 Ibs (SIC 24). These two industrial groups generate less than 0.1% of the hazardous waste generated by the sample group.

The lowest waste minimization ratio can be observed with the industrial group "Instruments" (SIC 38) at "0.2" and with "Chemical Products" (SIC 28) also at "0.2". The industrial group "Chemical Products" constitutes 19% of all companies of the sample group (or 25 companies) generating 78%

of the hazardous waste of the sample group while "Instruments" is only represented by four companies generating less than 0.1 % of the hazardous waste of the sample group.

Most of the industrial groups show a waste minimization ratio between "0.3" and "0.5".

(iv) Comparison of Waste Minimization Practices Implemented during the two Time Frames on the Basis ^of Waste Minimization Ratio

It is interesting to note that an analysis by industrial groups yields a more differentiate picture of implementation of waste minimization practices than an aggregated analysis of waste minimization practices over all waste streams reported by the sample group (see Table 7). The waste

minimization ratio (see Table 10) is a first approach to develop an overview of the waste

minimization practices implemented by industrial groups in the sample of North Carolina industry.

Increases, decreases or constancy of the waste minimization ratio over the two time periods shows how different the implementation activities of the various industrial groups actually seem to be given the overall decline in the number of waste streams at which waste minimization practices were reported to be implemented (see Table 7).

Comparing the waste minimization ratio of the industrial groups at the two time frames, it can be observed that out of the 13 different industrial groups analyzed, five groups indicated an increase in the waste minimization ratio by one to four tenths from the time prior to '86 to the time during

7 '86. Six industrial groups showed in a decrease in the waste minimization ratio with "Textile Mill Products" (SIC 22) and "Primary Metals Industry" (SIC 33) indicating the relatively largest decrease from "1" (prior to '86) to "0.4" (during '86) and "0.7" (prior to '86) to "0.3" (during

-

'86). Other industrial groups showed a ratio decrease by one to two tenths. Two industrial groups did not change the waste minimization ratio.

It could be valuable to investigate why those industrial groups that showed a decline in waste minimization ratio during '86 were not able to keep the level of waste minimization practices on the same level than for the time prior to '86. It might also be interesting to try to focus on those industrial groups with a relatively low waste minimization ratio in both time periods. The two industrial groups which show a relatively low waste minimization ratio in both time periods are

"Instruments" (SIC 38) and "Chemical Products" (SIC 28). While the first industrial group generated less than 0.1% of the hazardous waste reported by the sample group, the industrial group "Chemical Products" contributed to 78% of the hazardous waste of the sample group. To further focus an attempt for technical assistance and/or research projects, Appendix 6 and Appendix 7 (discussed in chapter 10.10 in more detail) are useful for correlation. Processes under each SIC code where no waste minimization practices reportedly had been implemented for the two time frames were presented.

7.9.3. Analvsis of Waste Minimization Practices by Waste Minimization Percentage (i) Introduction

An analysis on the basis of the waste minimization percentage is essentially a further differentiation of the previous analysis based on the waste minimization ratio. While the waste minimization ratio aggregates the waste minimization activity at waste streams under specific industrial groups, the analysis by waste minimization percentage distinguishes among the different waste minimization practices as described in chapter 7.6.1.

.

Again multiple answers could be given for the waste minimization practices implemented at one waste stream. The waste minimization percentage gives the percentage of particular waste minimization practice that were reported to have been

implemented at waste streams of a certain industrial group. The waste minimization percentage therefore takes into account the multiple answers that could be given. Taking the "Primary Metals Industry" as an example, the waste minimization percentage of 39% for "better housekeeping practices" (BH) (for the time prior to '86

-

see Table 11) indicates that at "better housekeeping practices" were implemented at 39% of the waste streams generated by this particular industrial group.

Similar to the waste minimization ratio criterion, the waste minimization percentage is not necessarily a quality criterion meant to measure success in waste minimization accomplishments (see chapter 10.9.1. for further argumentation). Still, the waste minimization percentage is a helpful tool to achieve a more detailed pattern of the waste minimization activities of the sample group.

Table 1 1 :Distribution of W a s t e Minimization Practices prior to ‘86 by process-specific SIC Code amow Samttle of North Carolina Industry

(sample size: 129 companies with 553 waste streams)

{percenmges in Table 11 am? vaste “&ation percentages 1 )

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In document North Carolina Industrv (Page 63-70)