Benchmarking Compost Quality in Ontario: Analytical Data and Findings 2011

Size: px

Start display at page:

Download "Benchmarking Compost Quality in Ontario: Analytical Data and Findings 2011"

Lee Kelley
5 years ago
Views:

1 Benchmarking Compost Quality in Ontario: Analytical Data and Findings 2011 by Cecily Flemming, Ministry of the Environment and Climate Change, and Dr. Lambert Otten, Professor Emeritus, University of Guelph

Purpose and Overview Purpose: Provide compost quality benchmark for Ontario before the regulatory changes in 2012 Present complete survey data from Leaf and Yard (L&Y) and Source Separated Organics

2 Purpose and Overview Purpose: Provide compost quality benchmark for Ontario before the regulatory changes in 2012 Present complete survey data from Leaf and Yard (L&Y) and Source Separated Organics (SSO) composts Outline: Regulatory Context Study and Findings Metals and Pathogens Foreign Matter and Maturity Conventional parameters Unregulated elements Persistent Organics Preliminary Conclusions 2

Context Ontario Standards Regulations drive compost quality Prior to 2012 Ontario producers had: One category of compost quality (re: regulated metal contaminants) Stringent metals limits for

3 Context Ontario Standards Regulations drive compost quality Prior to 2012 Ontario producers had: One category of compost quality (re: regulated metal contaminants) Stringent metals limits for feedstocks (i.e., feedstock in = finished compost) After September 2012: Feedstock metal limits were increased Allowing diversion of more feedstocks, including sewage biosolids and septage Three categories introduced: Categories A and B (to harmonize to CCME*) Original compost now called Category AA Retained O. Reg. 101/94 Leaf and Yard option 3 * CCME - Canadian Council of Ministers of the Environment

4 Compost Standards: Ontario History Element (µg/g) O. Reg.* 101/94 Environmental Compliance Approval** (L&Y) (L&Y) Regular Controlled Cat AA Cat A Cat B Arsenic Cadmium Chromium Cobalt Copper Lead Mercury Molybdenum Nickel Selenium Zinc * Recycling and Composting of Municipal Waste Reg. for uncontrolled L&Y composting. ** For generators operating via Environmental Compliance Approval (ECA) under EPA.

Compost Sampling Study - 2011 Timing of study to get a baseline a benchmark - of compost quality in Ontario prior to any changes in feedstocks Follow-up from MOECC study with Dr.

5 Compost Sampling Study Timing of study to get a baseline a benchmark - of compost quality in Ontario prior to any changes in feedstocks Follow-up from MOECC study with Dr. Otten - Compost Quality Assessment ( ) presented by in 2013 Dr. Lambert Otten (Wellington Applied Sci. Ltd.) sampled large L&Y and SSO facilities in Ontario operating under ECA Represents >80% of Ontario compost produced under ECA 5

Compost Sampling Study - 2011 Sampled at 18 large facilities: 10 Leaf and Yard (LY); 8 Source Separated Organics (SSO) composting Collected 10-grab composite samples May-July 2011 3 sample sets to

6 Compost Sampling Study Sampled at 18 large facilities: 10 Leaf and Yard (LY); 8 Source Separated Organics (SSO) composting Collected 10-grab composite samples May-July sample sets to MOECC lab; 2 to Wellington App. Sci. MOECC laboratory Analyses: Metals (regulated and unregulated) Pathogens (E. coli, Salmonella, Giardia, Cryptosporidium) Conventional parameters (LOI, moisture, nutrients, salts, etc.) Persistent Organics (PAHs, PCBs, Organochlorine, etc.) Wellington Applied Sci. Ltd. Analyses: Foreign matter Maturity (Respiration) 6

7 RESULTS Regulated Metals 7

8 Results - Regulated Metals in SSO, L&Y Regulated Metals SSO (Pooled data; n=24) L&Y (Pooled data; n=30) Compost Limit AA (µg/g dw) Mean Stdev Median Max Mean Stdev Median Max (µg/g dw) Arsenic Cadmium Chromium Cobalt* Copper Lead Mercury Molybdenum* Nickel Selenium** Zinc* * Significantly different means for L&Y vs. SSO according to t-test and Kruskal-Wallis (p<0.005) 8 ** For Se, 80% of samples had levels detected below amounts to be quantified reliably; All other metals detected in 100% of samples at or above method detection limits (MDL)

S1 S2 S3 S5 S6 S7 S8 S9 LY1 LY2 LY3 LY4 LY5 LY6 LY7 LY8 LY9 LY10 Mercury (µg/g) Regulated Metals- Examples of Sites Regulated metals all well below regulatory Limits (L) High variability

9 S1 S2 S3 S5 S6 S7 S8 S9 LY1 LY2 LY3 LY4 LY5 LY6 LY7 LY8 LY9 LY10 Mercury (µg/g) Regulated Metals- Examples of Sites Regulated metals all well below regulatory Limits (L) High variability between sites; Some deviation within a site SSO vs. L&Y means similar for most metals (except Co, Mo, Zn) Mercury (L=0.8 µg/g) Cadmium (L=3 µg/g) 0.1 Mean = 0.05±0.02 Mean SD Mean = 0.45 ±

10 Regulated Metals- Examples Low Cu and Zn levels vs standards Much lower than category A compost in 2012 and CCME limits (400 and 700 µg/g) Zinc (L =500 µg/g) Copper (L=100 µg/g) Mean = 43±17 SSO Mean 134±30 L&Y Mean 119±32 10

11 Regulated Metals- Examples Pb (lead) levels very low compared to Standards In 2016 the Bureau de Normalisation du Québec reduced Pb standard of Category A compost to 120 µg/g Lead (L =150 µg/g) SSO & LY Mean = 29±13 11

12 RESULTS Pathogens 12

13 Results - Pathogens E. Coli Results 2011 (Colony Forming Units/g dry weight) Compost n Geometric Mean Median 95th%ile Max % >1000 L&Y ,080 3,600 35% SSO ,100 38, ,000 56% Geometric means of generic (non-pathogenic) E. coli were low; however methods showed inconsistent results with some exceedences Further lab method comparison testing is underway 13

14 Pathogens in Compost COMPOST FACILITY SALMONELLA CRYPTO* GIARDIA* Max. (per 4g dw) Presence/Absence (+/-) SSO (n=2) SS SS SS SS SS SS SS SS L&Y (n=2) LY LY LY LY LY LY LY LY LY LY Salmonella Limit 3 MPN/4g dry wt One exceedence - same sample with 144,000 E. coli/g 14 * Parasites (n=3) determined by qpcr; - = negative; + = 1 to 99 cysts/g; ++ = >100 /g wet Note that % recovery, viability and infectivity were not accounted for in enumeration.

15 Pathogen Findings Regulated Bacteria Salmonella levels were very low ( 0.5 bacteria per 4 gram dw) E. coli were generally low (geometric mean < 500 colonies/g dw), but not consistent - further lab method testing is ongoing Parasites Human-specific Cryptosporidium and Giardia were detected in SSO samples at 12% and 37%, respectively These parasites were detected in L&Y at a lower frequency Analytical methods (PCR) did not take into account recovery, viability or infectivity of these parasites Further lab method testing is underway to determine a viability test 15

16 RESULTS Foreign Matter Content 16

17 Results - Foreign Matter, 2011 Data COMPOST TYPE FACILITY STONES (Ave %) PLASTICS (Ave %) GLASS* (Ave %) OTHER SHARPS* SSO SS (n=3) SS SS SS SS SS SS L&Y LY (n=3) LY LY LY LY LY LY LY LY LY Pooled SSO (24) Data L&Y (30) standards: Foreign Matter > 8 mesh screen size: <2% total FM <1% plastics No injurious material 2015 Standards (AA &A) foreign matter >3mm: <1% total FM, incl. <0.5% plastics and no sharp FM in 500 ml Note that gravel is not foreign matter 17 *Sharps - Material of a size or shape that reasonably can cause human or animal injury, or damage to equipment. (2004)

Foreign Matter - Observations Plastics Plastic found in greatest amount in facilities that accept plastic bags (S2 and S5) L&Y waste regularly contained plastic potting containers as well as some

18 Foreign Matter - Observations Plastics Plastic found in greatest amount in facilities that accept plastic bags (S2 and S5) L&Y waste regularly contained plastic potting containers as well as some plastic bags All facilities were within the interim 2004 standards, and looked to meet new standard (July 2015) of 0.5% plastics Sharps Sharps were very small pieces of glass, found in SSO but not in L&Y SSO produced mature compost that contained very little glass of a size considered detrimental to the public 18

19 RESULTS Compost Maturity 19

20 Results Maturity (Respiration) SSO Facility Moisture Ave CO 2 Evolved* L&Y Facility Moisture Ave CO 2 Evolved* (n=3) (%) (mg CO 2 -C/g OM/day) (n=3) (%) S LY S LY S LY S LY (mg CO 2 -C/g OM/day) S LY S LY S LY S LY Pooled Data SSO n= 8 sites 36.5 ± ± 4.0 LY LY L&Y n=10 sites 44.5 ± ±0.24 *CO 2 Evolution Standard on July 2015= 4 mg C (as CO 2 )/g organic matter (OM) dry wt/day 20

21 Compost Maturity - Observations A number of SSO compost samples failed (>20% of samples; 3 sites) CO 2 method not reliable in overly dry compost (e.g., 25% moisture) MOECC follow-up studies 2014 compared multiple methods Study underway to adopt Oxi-Top method at MOECC (EN ) used in Ireland 21

22 RESULTS Conventional and Unregulated Parameters 22

23 Results - Conventional Quality % Moisture Organic matter (LOI) Nutrients (N, P, K) Conductivity Salts 23

24 Results - Conventional Analyses Parameters SSO L&Y Mean Stdev Median Min Max Mean Stdev Median Min Max Total organic Carbon (mg/g dw) Total LOI (% dw) Moisture (%) ph TKN (mg/g dw) Phosphorus (mg/g dw) Potassium (mg/g dw) C:N Ratio Conductivity (ms/cm) Sulphate (mg/g) Chloride (mg/g) Sodium (mg/g dw)

25 Moisture Content (%) SSO significantly lower moisture and more variable than L&Y (p = 0.001) Consistent curing moisture now required ( 40%) as set out in 2012 Ontario Compost Quality Standards SSO (%) 35±12 L&Y (%) 42±5.1 25

26 Organic Matter (LOI) SSO has higher organic matter than L&Y (p<0.001) Both are highly variable Different mean C:N ratios (p=0.002) SSO 15±3 L&Y 19±6 SSO (%) 44±13 L&Y (%) 34±10 26

27 Compost Nutrients Nutrients highly variable between sites Mean Nitrogen and Total P higher in SSO than L&Y (p< 0.001) SSO (mg/g) 17.4±5.9 L&Y (mg/g) 10.5±2.7 SSO (mg/g) 4.3±1.7 L&Y (mg/g) 2.5±

Max 200-500 kgna/ha/yr, depending on soil type SSO

28 Salt Levels Salts higher in SSO MOECC recommend <4000 µs/cm On farm reg. Max kgna/ha/yr, depending on soil type SSO (µg/g) 3830±2580 L&Y (µg/g) 755±480 SSO (µs/cm) 5380±3170 L&Y (µs/cm) 3470±

29 Unregulated Elements L&Y Compost Elements (µg/g) % Detect Mean stdev Min Max Median 95 th %ile Antimony* Aluminum Barium Beryllium* Boron* Manganese Silver* 0 <0.2 Strontium Sulphur Thallium* 20 5 Tin Titanium Vanadium* * Elements in O.Reg. 153 Table 1: note that compost 95 th %ile concentrations are at or below soil background (residential/parks), except for Boron in L&Y (41 vs. 36 µg/g)

30 Unregulated Elements SSO Compost Elements (µg/g) % detect Mean stdev Min Max Median 95 th %ile Antimony* Aluminum Barium Beryllium* Boron* Manganese Silver* Strontium Sulphur Thallium* 4 5 Tin Titanium Vanadium* * Elements in Table 1, O. Reg. 153/04: note that 95 th %ile concentrations at or below soil background levels (for residential/parks/ici).

31 Other Elements Examples Mean Boron higher in L&Y than SSO; B similar to background for agricultural soils Sulphur and Sulphates higher in SSO SSO 22.8±6.5 L&Y 30.1±6.9 SSO 2400±780 L&Y 1500±370 31

32 RESULTS Persistent Organic Pollutants (POP) 32

33 Persistent Organic Pollutants in Compost, 2011 PAHs (polyaromatic hydrocarbons) 18 individual contaminants* PCBs (polychlorinated biphenyls) 77 congeners analysed Other Organochlorines (19)* including DDT (4)* Chlorobenzenes (13)* 33

34 PAHs - Summary of Results PAHs SSO L&Y SSO vs. LY Table 1** (ng/g dry wt) Mean Median 95 th %ile Mean Median 95th %ile t-test (Res/ICI) Naphthalene Acenaphthylene Acenaphthene Fluorene Phenanthrene Anthracene Fluoranthene Pyrene Benzo(a)anthracene Chrysene Benzo(b)fluoranthene Benzo(k)fluoranthene Benzo(e)pyrene Benzo(a)pyrene Perylene Indeno(1,2,3-c,d)pyrene Dibenzo(a,h)anthracene Benzo(g,h,i)perylene Ʃ16 PAHs*** 4,670 4,020 10,630 4,859 4,230 10, ,685 Red- mean values with p<0.05, significantly different between SSO and L&Y by t-test (2-tailed, equal variance, n=54) 34 ** Bold median values are greater than Brownfields residential soil background values in Table 1 of O.Reg. 153/04 *** Sum of the 16 PAHs being on USEPA list of priority pollutants (excluding only benzo(e)pyrene and perylene).

35 Total PAHs Total Σ16 PAHs similar L&Y vs. SSO Same magnitude as European compost (medians 2000 to 4000 ng/g for SSO) (Brändli et al. 2005) Lower than soil agri backgrounds (Table 1 O. Reg.153/04) SSO & LY Mean 4750±2300 ng/g dw) 35

36 Individual PAHs Levels Low, roughly equivalent to soil backgrounds (i.e., O.Reg. 153 Table 1) Medians of 12 of 16 PAHs < soil background Means of 4 of 16 PAHs higher by <2x 95 th percentiles higher by less than 4x Few individual PAHs higher in SSO, others higher in L&Y E.g., Phenanthrene SSO (ng/g) 650±700 L&Y (ng/g) 300±350 36

37 PCBs Summary of Results PCB Statistics Units SSO L&Y Frequency of Detection (n=24) (n=30) No. of congeners (of 77) detected % Samples containing PCB % Max conc. of any congener (in any one sample) ng/g Total PCB concentrations Mean ng/g Stdev ng/g Min ng/g Max ng/g Median ng/g th percentile ng/g

38 PCBs PCBs were >5x lower than 2004 standard (500 ng/g) Slightly higher in SSO than L&Y (p=0.06) SSO 60 ± 34 ng/g L&Y 42 ± 27 ng/g Same magnitude as Europe SSO compost medians ng/g (Brändli et al. 2005; JRC Report, 2014) Lower than background levels in agri soils (300 ng/g) (Table 1, O. Reg. 153/04) 38

39 Organochlorines- Summary of Results Frequency of Detection SSO (n=24) L&Y (n=30) No. of chemicals detected (of 19) 11 9 % of samples containing OCs Max conc. of any OC (ng/g dry wt) Contaminants Found (ng/g) Max Median Max Median Aldrin* <1 <1 <1 a-chlordane* Ʃ DDT and metabolites* Dieldrin* Endosulphan I 3 3 <1 <1 Endosulphan II <1 <1 Endosulphan sulphate* <1 <1 Endrin* <1 <1 2 2 Heptachlor* <1 <1 <1 Ʃ Hexachlorocyclohexanes* 1 2 <1 <1 Mirex <1 <1 Photomirex <1 <1 trans-nonachlor Oxychlordane <1 <1 * Compounds listed in Table1 soil background levels (O.Reg.153 under EPA) (all 40ng/g) 39

40 Organochlorines (OCs) Conclude Low levels in Compost: 8 OCs were listed in Table1 (O.Reg.153/04) background OC Conc. 10 to 50x lower than Agricultural soil backgrounds In-line with European JRC Sampling and Analysis campaign - levels for 7 pesticides each < 50 ng/g Australian Limit is sum of 10 OC pesticides < 500 ng/g Example DDT: SSO + L&Y (n=54) Average = 11.8 ±

41 Summary of Resuls - Chorobenzenes (CBs) Frequency of Detection SSO (n=24) L&Y (n=30) No. of chemicals detected of No and % of samples containing CBs 10 (42%) 10 (33%) No. of facilities with CBs detected 4 of 8 5 of 10 Max conc. of any CB (ng/g dry wt) 9 3 Contaminant Conc. (ng/g) Max Median Max Median Hexachloroethane* 5 2 <1 1,3,5-trichlorobenzene ,2,4-trichlorobenzene* ,2,3-trichlorobenzene 4 3 <1 Hexachlorobutadiene* 4 4 <1 2,4,5-trichlorotoluene 4 3 <1 2,3,6-trichlorotoluene 8 3 <1 1,2,3,5-/1,2,4,5-tetrachlorobenzene ,2,3,4-tetrachlorobenzene 3 2 <1 2,6-dichlorobenzyl chloride Pentachlorobenzene <1 <1 2 2 * Listed in O.Reg. 153 (Table 1) for agricultural soil background at conc. 10 to 50 ng/g 41

42 Broad Conclusions Ontario compost is high quality with a history of stringent standards Regulated and Unregulated metals very low Persistent organics pollutants also very low Establishes benchmark data for Ontario: for comparisons with other residuals to track changes in compost quality with any changes in feedstock use after

Questions and Contacts Thanks to participating Municipalities and Compost Producers in Ontario Grateful to MOECC Laboratory Services Branch for

43 Questions and Contacts Thanks to participating Municipalities and Compost Producers in Ontario Grateful to MOECC Laboratory Services Branch for analyses For more info contact: at Standards Development Branch Operations Division, Central Region 43

Qualitycheck Proficiency Testing Schemes Independent external evaluation of the analytical competence of testing laboratories. Application Form

Qualitycheck Proficiency Testing Schemes Independent external evaluation of the analytical competence of testing laboratories - 2019 Customize your participation, and only pay for what you need! The laboratory