page 1 of 22 october 21st, 2013 peter rotheisler manager of

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AECOM

300 Town Centre Boulevard

3rd Floor

Markham, Ontario

L3R 5Z6

www.aecom.com

905 477-8400 tel

905 477-1456 fax

October 21st, 2013

Peter Rotheisler Manager of Environmental Services Central Okanagan Regional District 1450 KLO Road Kelowna, British Columbia V1W 3Z4

Re: Westside Regional Wastewater Treatment Plant Odour Mitigation and Foul Air Assessment Study Letter Report - FINAL

1. Introduction

The Westside Regional Wastewater Treatment Plant (WRWWTP) located in the District of West Kelowna, British Columbia is a Class IV tertiary treatment plant owned by the Regional District of Central Okanagan (RDCO). It services a population of more than 43,000 including Peachland, District of West Kelowna and West Bank First Nation. The average daily flow in 2012 was 9,282 m3/day with approximately 5,000 tonnes of biosolids produced.

Local residents have raised concerns about the WRWWTP processes’ and biosolids hauling operation causing offensive odours and the possibility of high Hydrogen Sulphide exposure. The WRWWTP sludge handling operation has been identified as a potential source of odour emissions. There are currently two (2) solids stream that are managed: the primary solids stream at the treatment plant which undergoes fermentation; and the waste secondary solids stream which is treated with a DAF thickener. Both streams are pumped to a centrifuge for dewatering with the dewatered sludge transported offsite for land application.

Through the implementation of a long-term or permanent stabilization method, the WRWWTP is striving to address the ongoing odour concerns while aiming to produce Class A Biosolids, the highest quality biosolids achievable under the Organic Matter Recycling Regulation (OMRR). The WRWWTP currently produces Class B biosolids which are organic matter that meet a quality of biosolids achievable under OMRR and allows for selected land application use. The Class A Biosolids would offer greater flexibility for the use and distribution of the WRWWTP’s biosolids.

AECOM has been retained by the Regional District of Central Okanagan (RDCO) to recommend methods of further mitigating odours resulting from the WRWWTP processes and to evaluate the hydrogen sulphide exposure potential in the neighbouring residential areas. The study will consider the potential financial, social and environmental costs and benefits of additional odour mitigation and foul air collection options available for the WRWWTP. The evaluation includes an economic and technical feasibility of methods to achieve Iong-term (months) or permanent stabilization and odour reduction of the dewatered sludge. .

This letter report outlines the evaluation of existing odour control system performance and is organized as follows:

Section 2: presents an overview of the WRWWTP odour control system. Section 3 describes the methodology and results of the preliminary filer odour sampling

program Section 4 discusses the various sludge stabilization methods which would produce higher

quality of biosolids; Section 5 reviews the alternatives to landfilling the WRWWTP dewatered sludge; and

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Section 6 summarizes the findings of the odour mitigation study and provides recommended strategies on improving the odour mitigation and foul air collection.

2. Existing Odour Control System Description

The WRWWTP odour emissions are controlled and treated by an odour control system using an organic media open biofilter technology. The system controls the emissions from the following process areas identified as the primary sources of odour emissions:

Sludge handling building Headworks building Screening building Fermenter #1 and #2 Thickened Waste Activated Sludge (TWAS) vault Equalization tank 1 Bioreactors #1, #2, #3, #4, #5, #6

The odour control system includes the exhaust fans, ductwork, dampers and a moisture control system. 3. Preliminary Field Odour Sampling

In order to identify the odour mitigation and control strategies, and to better understand the WRWWTP operation, a preliminary field odour sampling was carried out. The objectives of the preliminary field odour sampling program were to:

Identify the source for odour complaints; Determine the extent of the odour and other odour-causing contaminants in the ambient air

by monitoring Hydrogen Sulphide (H2S) concentrations and collecting samples; Establish a baseline concentrations of odour-causing contaminants; and Collect the data necessary to proceed with the development of an odour mitigation plan that

would reduce the odour and health concerns stemming from the biosolids hauling operations.

3.1 Sampling and Monitoring Approach

The preliminary field program included the monitoring of H2S and the sampling of Total Reduced Sulphurs (TRS) inside the plant and in the vicinity of the four (4) selected sensitive receptors. The goal was to obtain an initial evaluation of the current odour issues and determine if an additional expanded program will be required.

At the beginning of the program, AECOM was given a tour of the WRWWTP to better understand the wastewater treatment operation and to inspect the process equipment that could be a potential source of odour. AECOM also investigated the locations of all the four (4) sensitive receptors.

The sampling program included:

H2S concentration measurements by using a Jerome 631X analyzer with the capability to detect the levels as low as 0.003 ppm (4 μg/m3).

TRS samples were collected using the US EPA approved method for sampling with summa canister and the samples are analyzed by a certificate laboratory for:

o Hydrogen sulphide o Dimethyl Sulphide o Disulphide compounds; and o Mercaptans.

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Summa canisters are an evacuated, highly polished stainless steel sampling containers. The canister valve is simply opened and the vacuum inside the canister draws in a sample within a matter of seconds.

The field sampling was performed from September 9, 2013 to September 18, 2013. TRS grab samples were collected on September 9, 10, 16 and 18. A total of 12 grab samples were collected for laboratory analysis.

As the biosolids handling building had been previously identified as a potential source of odour, H2S measurements have been taken at the outside face of the truck access rolling doors.

3.2 Monitoring and Sampling Locations

The approximate location of each H2S monitoring point and TRS sampling point is identified on Figure 1 and Figure 2, respectively. The monitoring and sampling locations within the plant were selected based on their odour generating potential and to assist with the assessment of the odours generated by the WWTP as a whole.

3.2.1 Sensitive Receptors

The following is a summary of the sensitive receptors used for the ambient sampling program.

Receptor R1 is a residential neighbourhood located by the Okanagan Lake, southwest of the WWTP.

Receptor R2 is a residential neighbourhood located adjacent to the biosolids truck hauling route.

Receptor R3 is a residential neighbourhood located north of the WRWWTP and west of the biosolids truck hauling route. This sensitive receptor site was selected to assess both the ambient odours from the WRWWTP and to assess the impact of ambient odours due to the truck hauling operation.

Receptor R4 is a residential neighbourhood located by the waterfront, west of the WWTP.

Sampling at the sensitive receptors was conducted when the prevailing winds positioned the receptor downwind to the WRWWTP and at the receptor nearby the biosolids truck hauling route during a truck hauling operation.

3.2.2 Westside Regional Wastewater Treatment Plant Locations (WRWWTP)

Ambient air concentrations of H2S were recorded near all the processes within the WRWWTP in order to identify the main sources of odour (Figure 1). TRS samples were collected at locations where concentrations of H2S were above 1ppm were reported and detected using the Jerome 631X unit (See Table 2-1). These include the following locations:

The Sludge Handling Building The Biofilter Area

3.3 Results

3.3.1 Hydrogen Sulphide (H2S) Sample Data

Table 3-1 presents the results of the H2S monitoring conducted throughout the WRWWTP during the preliminary field investigation. The H2S values measured during the preliminary sampling program are under 5 ppm (6,965 μg/m3) with the exception on September 13th, 2013 when an H2S concentration of 13 ppm (18,110 μg/m3) was recorded in the Sludge Handling Building. Other notable field measurements included an H2S measurement of 4.40 ppm (6,219 μg/m3) recorded on September 10th, 2013 at the biofilter. The H2S concentrations at the selected receptors measured between 0.001 and 0.057ppm (1 – 79 μg/m3).

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Table 3-1 Recorded H2S Levels at WRWWTP

Monday, September 9, 2013

Location Sampling Time Measurement (ppm)

Sludge Handling Building

‐ Loading of truck

13:32 – 13:39 0.22 – 0.32 ppm

306 – 446 μg/m3

14:59 – 15:00 0.29 – 0.69 ppm

403 – 961 μg/m3

Blue Building 13:45 0.002 ppm

3 μg/m3

Influent Chamber 13:46 0.002 ppm

3 μg/m3

Screening Building 13:48 – 13:55 0.019 – 0.79

26 – 1100 μg/m3

Grit Room 13:56 0.003 ppm

4 μg/m3

Fermenter 1 Vent 13:57 0.002 ppm

3 μg/m3

Fermenter 2 Vent 13:59 0.004 ppm

5 μg/m3

Sludge Dewatering Building 14:02 – 14:16 0.003-0.25 ppm

4 – 348 μg/m3

Channel near the DAF Building

14:22 0.071 ppm

99 μg/m3

Biofilter 14:26 -14:28 0.21 – 1.80 ppm

292 – 2507 μg/m3

Bioreactors Influent 14:30 – 14:34 0.007 – 0.60 ppm

10 – 836 μg/m3

Tuesday, September 10, 2013


-Truck Loading

8:55 -8:57 0.47 – 2.0 ppm

654 – 2786 μg/m3

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13:30 – 13:35 0.70 – 1.10 ppm

975 – 1532 μg/m3

Biofilter 9:32 – 9:43 0.23 – 4.40

320 – 6129 μg/m3

R1 – Whitworth Lift Station

12:55 – 12:58 0.002 ppm

3 μg/m3

17:02 0.002 ppm

3 μg/m3

Screening Building 13:18 – 13:21 0.002-0.19 ppm

3 – 265 μg/m3

Sludge Dewatering Building 13:22 0.002 ppm

3 μg/m3

13:27 0.004 ppm

5 μg/m3

Grit Room 13:23 0.006 ppm

8 μg/m3

Friday, September 13, 2013 – Wind Conditions: North 8km/h

Influent Channel 9:08 0.014 ppm

19 μg/m3

Sludge Handling Building 9:10 13.0 ppm

18,110 μg/m3

R3 – truck passing 9:32 0.057 ppm

79 μg/m3

Monday, September 16, 2013– Wind Conditions: West-North-West 18km/h

R2 19:15 0 ppm

R3 19:22 0 ppm

R4 19:35 0 ppm

Wednesday, September 18, 2013 - Wind Conditions: Not available 4 km/h

R4 9:01 – 9:27 0.001 – 0.025 ppm

1 – 35 μg/m3

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R2 9:35 -9:41 0.001-0.002 ppm

1 – 3 μg/m3

R3 9:47 – 9:53 0.001-0.002 ppm

1 – 3 μg/m3

Source: Environment Canada, 2013

Note: All values expressed in μg/m3 have been converted from ppm based on standard conditions of 25 °C and 101.325 kPa.

3.3.2 Total Reduced Sulphur (TRS) Sample Data

Table 3-2 summarizes the results of the laboratory analysis of TRS for the collected summa canister samples. Full copies of the sampling results are provided in Appendix A. A total of 12 samples were analysed for TRS. Four (4) samples were collected within the WRWWTP while the remaining eight (8) samples were collected at the sensitive receptors. All samples collected at the sensitive receptors contained no detectable concentrations of TRS. TRS concentrations were detected in samples collected within the WRWWTP during the sludge loading operations and at the biofilter responsible for treating the odourous air. The highest concentrations of TRS were detected in the sample collected over a full hauling truck of biosolids. During the truck loading operations, concentrations of TRS were detected in the sludge handling building, but significantly lower than measured above the full hauling truck.

Table 3-2 Total Reduced Sulphur Ambient Air Sampling Results

Locations Date

Total Reduced Sulphurs Detected

Hydrogen Sulphide

Methyl Mercaptan

Ethyl Mercaptan

Dimethyl Sulphide

Dimethyl Disulphide

Sludge handling Building – During Sludge Loading Operation

09/09/2013 190 μg/m3

0.130 ppmV

53 μg/m3

0.027 ppmV

Not Detected

19 μg/m3

0.007 ppmV

27 μg/m3

0.007 ppmV

Sludge Handling Building – Above a full hauling Truck

09/13/2013 27,000 μg/m3

20 ppmV

23,000 μg/m3

12 ppmV

27 μg/m3

0.01 ppmV

3,200 μg/m3

1.2 ppmV

1,700 μg/m3

0.43 ppmV

Biofiler - Inlet Port

09/10/2013 2,500 μg/m3

1.8 ppmV

400 μg/m3

0.2 ppmV

Not Detected

77 μg/m3

0.03 ppmV

68 μg/m3

0.02 ppmV

Biofilter - Mid-Center

09/10/2013 790 μg/m3

0.57 ppmV

160 μg/m3

0.08 ppmV

Not Detected

31 μg/m3

0.01 ppmV

Not Detected

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3.3.3 Summary of Canadian Regulations on Odour-causing compounds

The province of British Columbia currently regulates Total Reduced Sulphur compounds in ambient air. These compounds include:

Hydrogen Sulphide Methyl Mercaptan Dimethyl Sulphide Dimethyl Disulphide Carbon Disulphide Carbonyl Sulphide

Table 3-3 presents the current ambient air quality standards for odour-causing compounds in British Columbia and in other provinces in Canada.

Table 3-3 Provincial Regulations on Odour-Causing Compounds

Provinces Odour Based Regulation British Columbia Total Reduced Sulphurs

Maximum Acceptable Levels 1-hour average – 28μg m-3 , 20 ppb 24-hour average – 6μg m-3 , 4 ppb Maximum Desirable Concentration 1-hour average – 7μg m-3, 5 ppb 24-hour average – 3μg m-3 , 2 ppb

Alberta Hydrogen Sulphide 1-hour average – 14 μg m-3, 10 ppb 24-hour average – 4μg m-3, 3 ppb

Ammonia 1-hour average – 1,400μg m-3, 2,000 ppb

Carbon disulphide 1-hour average – 30μg m-3, 10 ppb

Saskatchewan Hydrogen Sulphide

Maximum Acceptable Levels 1-hour average – 15μg m-3, 10.8 ppb 24-hour average – 5μg m-3, 3.6 ppb

Manitoba Ammonia 1-hour average – 1.4 μg m-3, 2.0 ppb

Hydrogen Sulphide Maximum Acceptable Levels 1-hour average - 15μg m-3, 11 ppb 24-hour average – 5μg m-3, 4.0 ppb Maximum Desirable Concentration 1-hour average - 1μg m-3

Odours 1 Period of time the contaminant is measured: Two tests not less than 15 minutes apart nor more than 60 minutes apart Maximum Acceptable Levels Residential Zone – 2.0 Odour units Industrial Zone – 7.0 Odour units Maximum Desirable Concentration Residential Zone - < 1.0 Odour unit

Note 1: Nuisance odours from environmentally-regulated developments are managed using a strategy based on the prevention/minimization of odour releases and the use of a community based standard to determine the acceptability of the ambient odour in the community. It is intended that the odour unit limits be used only for evaluating potential impacts on a

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community during the environmental impact assessment of new or modified developments.

Ontario

Ammonia 24 Hour average – 100 μg m-3, 144 ppb

Hydrogen Sulphide 10 minute average – 13 μg m-3, 9 ppb 24 Hour average – 7 μg m-3, 5 ppb

Total Reduced Sulphur 10 minute average – 13 μg m-3, 9 ppb* 24 Hour average – 7 μg m-3, 5 ppb*

Mercaptans 10 minute average – 13 μg m-3, 7 ppb

MOE Environmental Protection Action Odour – 1 Odour Unit

Quebec Hydrogen Sulphide 4 minute average – 6 μg m-3, 4 ppb 1 year average – 2 μg m-3, 1 ppb

Ammonia 4 minute average – 4 μg m-3, 6 ppb City of Montréal Odour – 1 Odour Unit

Note: * Total Reduced Sulphur values in ppb expressed as Hydrogen Sulphide ** Mercaptans value in ppb expressed as Methyl Mercaptan

3.3.4 Emissions Standards and Guidelines

The TRS sampling results indicated that no reduced sulphur compounds could be identified at the sensitive receptor locations; however, H2S concentrations were detected during the monitoring event. The province of British Columbia does not currently have an ambient air quality guideline specifically for hydrogen sulphide. Consequently, the Ontario 10 minute-average standard for hydrogen sulphide was used to interpret the monitoring results. The monitoring technique used for this study provides only instantaneous or snap shot H2S measurements; however, to provide a high-level assessment of regulatory compliance, the values were adjusted using an averaging period factor. The highest H2S values were recorded on September 13th, 2013 on at Receptor R-3 as the biosolids truck drove by and on September 18th, 2013 at Receptor R-4 as the wind blew downwind of the WRWWTP, with concentrations of 86 μg/m3 (0.06 ppm) and 38 μg/m3 (0.03 ppm), respectively. When averaging these concentrations over a 10 minute period, the Ontario H2S 10 minute-average guideline of 13 μg/m3 (0.009 ppm) may have been exceeded on one (1) occasion, at Receptor R-3, during the sludge trucking hauling operation. It should be noted that the averaging period factor offers a conservative estimate of the short-term exposures levels and continuous H2S sampling should be conducted to validate this observation.

The effects of short-term exposure to H2S have been a concern for the residents living nearby the WRWWTP. In British Columbia, the short term exposure limit (STEL) of H2S is 10 ppm (13,930 ug/m3) (Worksafe BC, 2013), which is defined as the time weighted average (TWA) concentration of a substance in air that may not be exceeded over any 15 minute period. During the preliminary odour study, the most elevated concentration of hydrogen sulphide detected in the receptor areas was 0.057 ppm (79 μg/m3), which is significantly lower than the STEL of 10 ppm. Nevertheless, at concentration less than 1 ppm (1,393 μg/m3), H2S can be detected by its non-pleasant “rotten eggs” smell (Worksafe BC, 2010). However, aside from a detectable odour, the possibility of the exposure causing adverse health effects to the residents surrounding the WRWWTP is significantly low.

3.4 Summary of Findings

The existing WRWWTP operational approach to mitigating odours includes:

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Reducing H2S generation by managing the production of volatile fatty acids (VFAs) in the fermenter. The height of the sludge blanket maintained in the fermenter is directly proportional to the levels of H2S that results in both the fermenter and in the sludge loading building. The WRWWTP staff are able to adjust the fermenter operation to reduce the H2S production; however, this cannot be done at the expense of meet the facilities discharge permits. Meaning this approach is seasonal and limited where lower VFA’s are permissible.

Utilizing a biofiltration system with the capabilities of treating 7,871 L/s of air. Two (2) biofilter supply fans are used to exhaust the odourous emissions from various areas, such as the sludge handling building and primary fermenters, in the WRWWTP through to the biofilter. The biofilter is constructed using concrete blocks and is filled of a fine organic media. This biofilter design uses a sprinkler system manage the moisture levels in the organic media.

The addition of Bioxide®, a proprietary nitrate oxygen solution, to reduce odours from the dewatered biosolids prior to storage and hauling.

Below is a list of findings and observations for the sampling field program:


Air flow measurements at the man door opening indicate the sludge loading building to be under a positive pressure. This was confirmed by the recorded readings of the H2S at the outside face of the rolling door, which were similar in concentration to measurements inside the sludge loading building. This presents a possible source of increased ambient odours at the WRWWTP.

Organic Biofilter Vessel

Spots were identified on the top of biofilter media where the H2S concentrations were almost equal to the inlet concentration (i.e. indication of short-circuiting or untreated foul air exiting the filter bed).

Identified foul air escaping between the biofilter vessel blocks and internal liner.

The current biofilter does not include a primary humidification system.

Information provided by the WRWWTP operations staff indicates that the current moisture control system is challenged to saturate the media throughout the filter vessel.

Biofilter media appears depressed in the centre and less dense around the perimeter of the vessel.

There is no measurement of the pH in the sump in order to monitor the media performance. There is little biological reaction on the media when the pH of the irrigation water coming off of the media is higher than 8. Under normal biofilter operation, microorganisms on the media biodegrade reduced sulphur compounds (such as H2S) into sulphuric acid. This production of sulphuric acid will decrease the media pH and the pH of the drainage as well. For a properly operating biofilter, the pH of the bed drainage should be in the range 6 – 8. If the pH is below 6, the duration of the “on” time of the moisture control system should be increased to bring it into this range. If the pH of the drainage exceeded 8, it indicates that the biofilter is not working properly and there is insufficient biodegradation of reduced sulphur compounds.

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Other Process Areas

Some of the uncovered process areas (i.e. bioreactor influent) recorded positive H2S emissions.

Certain process areas, such as the sludge handling building, are not operating under negative pressure to prevent fugitive odour emissions and generating H2S and odours are not.

4. Sludge Stabilization

4.1 Sludge Stabilization Objective

The WRWWTP is currently generating approximately 14,000 kg/d of dewatered sludge. The dewatered sludge ranges from a ratio of 2:1 to 3:1, fermented primary sludge (FPS) to waste activated sludge (WAS). The two components of the sludge which are FPS and WAS are in an unstabilized state. The dewatered sludge which is also labelled as biosolids is transported by truck/trailer to an offsite, remote stockpile location.

Residents close to the WWTP and along the truck/trailer haul route have registered odour complaints. These odour complaints are expected to be associated with the biosolids loading operation and when the truck/trailer unit leaves the WRWWTP and travels along the haul route. It is also noted that pungent odour complaints have been registered at the outdoor sludge stockpile locations. Such complaints have not been received for 1 or 2 years and the RDCO aims to minimize these complaints through effective site management.

The generation of odours from biosolids are linked to the presence of abundant sources of food for microorganisms, including proteins, amino acids and carbohydrate. The microorganisms in the biosolids degrade these energy sources and generate odour causing compounds. Organic and inorganic forms of sulfur, mercaptans, ammonia, amines, and organic fatty acids are identified as the most offensive odor-causing compounds associated with biosolids handling processes. These compounds are typically released from the biosolids by heat, aeration and digestion (U.S. EPA, 2000b).

The Organic Matter Recycling Regulation (OMRR) defines biosolids as stabilized municipal sewage resulting from municipal wastewater that has been sufficiently treated to reduce pathogen densities and vector attraction to allow the sludge to beneficially recycled (B.C. Reg 18/2002). Pathogens are the organisms or substances capable of causing disease while vector are any organism capable of transmitting a pathogen from one organism to another. Therefore, the reduction of vector attraction would involve a reduction in the food source which attracts the vector (i.e. insects, rodents and birds) (U.S. EPA, 2003a).

Stabilization of sludge by physical, chemical or biological processes significantly reduces the organic fraction of the sludge and thereby reduces the potential for odour generation. Sludge stabilization also improves the quality of the sludge and results in increased options for reuse. The following sections detail various sludge long-term or permanent stabilization methods that results in:

Reduced odour potential from the time the sludge is processed on site to the time it is land applied;

A higher quality of biosolids by reducing odour, pathogen densities and vector attraction; Process improvements/changes to produce biosolids that meet Class A standards.

4.2 Sludge Stabilization Methods

There are three (3) types of stabilization methods: physical, biological and chemical.

Physical methods include air drying, heat treatment. The effectiveness of air drying depends on the local climate and the biosolids must dry for a minimum of 3 months at a temperature of above 0°

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Celsius under the regulation (B.C. Reg 18/2002). The air drying process is usually used subsequent to a biological process in order to meet the vector attraction requirement (U.S. EPA, 2003a). The heat treatments either involve the use of hot gases or a rotary kiln to treatment the sludge at high temperature for an extended period of time. No further processing of the sludge is required after the heat treatment because it also meets the requirements for vector attraction reduction (the percent solids must be at least 90% before mixing the sewage sludge with other materials) (U.S. EPA, 2003a). These physical methods do not remove the food source and therefore result in a temporarily stable biosolids product. Furthermore, heat drying of raw wastewater solids tends to produce a more odourous product, thus reducing its marketability (U.S. EPA, 2006).

The biological processes include aerobic, anaerobic digestion and composting. In aerobic digestion, sewage sludge is biochemically oxidized by bacteria in an open or enclosed vessel to convert volatile solids to carbon dioxide, water, and nitrate nitrogen whereas anaerobic digestion is a biological process that uses bacteria that function in an oxygen-free environment to convert volatile solids into carbon dioxide, methane, and ammonia (U.S. EPA, 2003a). These biological processes produce the highest level of permanent stability of biosolids by significantly reducing the presence of pathogens and the degree of vector attraction, thereby limiting the chance for future putrification and odour production. Composting is the controlled, aerobic decomposition of organic matter which produces a humus-like material. Sewage sludge which is to be composted is generally mixed with a bulking agent such as wood chips which increases porosity in the sewage sludge, allowing air to more easily pass through the composting material and maintain aerobic conditions (U.S. EPA, 2003a).

Chemical processes include the use of pH elevating chemicals such as lime, oxidants such as hydrogen peroxide and potassium permanganate or proprietary chemicals such as Saphyr®, and Bioxide®. pH elevating processes include lime stabilization and alkaline stabilization. Lime or alkaline stabilization involves the addition of – either hydrated lime; Ca(OH)2; quick lime, CaO; or lime containing kiln dust – to the sewage sludge in sufficient quantities to raise the pH (U.S. EPA, 2003a). Oxidizing agents can act as a bactericides and inhibit biological processes (U.S. EPA, 2000b). Other chemicals substitute the oxygen source to prevent sulphate uptake and thus the formation of sulphide.

The alkaline stabilization, elevated pH treatment method, reduces vector attraction by reducing or stopping biological activity (U.S. EPA, 2003a). However, this reduction in biological activity is not permanent. Furthermore, the pH must remain above 10 for the microbial activity and the associated production of odorous gases to be greatly reduced or eliminated. One of the pitfalls of this approach is the A generation of other odourous gases, including ammonia and trimethylamine, that are produced as a result of high pH and temperature conditions (NBP, 2005).

Oxidants can be initiated quickly at a low capital cost. The effectiveness of these agents are limited to the area in which they can be dispersed. This is considered to be a temporary method of reducing the odour in the biosolids.

Alternatively, there are chemicals such as Saphyr® and Bioxide® that remove the existing sulphide by introducing nitrate oxygen into a waste stream and create an environment in which certain naturally occurring bacteria thrive. However, such chemicals are a temporary odour mitigation solution and serves as a temporary stabilization solution as the food source is not consumed.

4.3 Comparative Analysis of Stabilization Methods

The goal of the RDCO is to implement a long-term or permanent stabilization method to significantly reduce the odour generation during transport and placement by reducing the vector attraction and improve the quality of biosolids.

Physical methods like heat treatment processes were not further considered because they produce nuisance odours when treating undigested wastewater residuals. Furthermore, since they do not reduce the food source; odours can increase if the biosolids become wet, which can happen from condensation during cooling or through other mechanisms. The most effective way of reducing odours when using heat treatment processes is to continue to digest prior to dewatering and drying. In addition, the end-product must be properly stored to ensure that is not exposed to moisture before

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use. Exposure to significant moisture presents a potential anaerobic decomposition which leads to odours (U.S. EPA, 2006).

Chemical processes such as elevated pH methods and proprietary chemicals are appropriate for short-term stabilization goals. They can be effective in reducing odour during the storing and transportation of the biosolids, however, monitoring and the periodic addition of chemicals prior to distribution is required in order to achieve long-term stabilization. Chemical processes do not remove the underlying cause of putrification and odours, i.e., the food source; but rather, they change the environment such that microbial activity cannot be supported (AnnMadge, Reimers, Smith, & Pillai, 2006). Therefore, chemical processes alone do not provide permanent or long-term stabilization of wastewater residuals. Combinations of chemical treatment and other stabilization methods such as heat treatment or air-drying are required to produce longer term stabilized biosolids. For instance, with lime stabilization, there is a potential for odor problems after the pH has dropped below 10.5 and a potential for pathogen regrowth if the pH drops below 9.5 while the material is stored prior to use (U.S. EPA, 2003a & U.S. EPA, 2000a).

On the other hand, proprietary chemicals, such as Saphyr® and Bioxide® serve as a temporary stabilization method. Also, the use of proprietary chemicals on undigested residuals can prove costly as a greater amount of chemicals are required. For these reasons, chemical processes are not considered suitable permanent or long term stabilization approaches for the RDCO.

The stabilization processes that can successfully provide long-term or permanent stabilization when paired with the existing processes for the WR WWTP include:

Aerobic digestion; Anaerobic digestion; and Composting.

These aforementioned processes produce the highest level of permanent stability of biosolids by providing treatment in which the cause for putrification and odours are consumed or oxidized prior to use.

These processes are discussed in greater detail below and a summary of the advantages and disadvantages of each process is provided in Table 4-1. Summary of the various sludge stabilization methods and a comparative analysis of each can be found in Appendix B.

4.3.1 Aerobic Digestion

In aerobic digestion, sewage sludge is biochemically oxidized by bacteria in an open or enclosed vessel. To supply these aerobic microorganisms with enough oxygen, either the sewage sludge must be agitated by a mixer, or air must be forcibly injected. Under proper operating conditions, the volatile solids in sewage sludge are converted to carbon dioxide, water, and nitrate nitrogen. Aerobic digestion typically reduces bacterial and viral pathogens by 90% or more and the volatile solids content (the microbes’ food source) of the sewage sludge by 40% to 70%, depending on the conditions maintained in the system (U.S. EPA, 2003a).

The primary and thickened waste activated sludge would be digested prior to the dewatering process. Aerobic digestion systems can be operated in batch or continuous modes. The primary difference between the two modes is the manner in which supernatant is removed from the process. For both modes, the aeration and mixing within the tank continues until the stabilization process is complete. Aerobic digesters are typically uncovered, unheated tanks of steel or concrete construction. Recent installations have included covers to maintain temperature within the process (U.S. EPA, 2003a).

Key advantages to using aerobic digestion are the low capital cost and simple operational control (National Biosolids Partnership [NBP], 2005).

The primary disadvantage that is typically attributed to the aerobic digestion process is the relatively high energy requirement associated with oxygen transfer. Developments in the process, such as increased oxygen transfer efficiency using fine bubble diffusion and operation at thermophilic temperatures, have reduced the energy requirements. It is a process that also requires a significant

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amount of space. Other disadvantages include reduced efficiency during cold weather and the relatively poor dewatering ability of the solids after digestion (NBP, 2005).

The conventional aerobic digestion process (mesophilic process without the addition of heat) designed for Class B biosolids, must operate 20 to 60 days at 15°C to 35°C. A variation to the conventional aerobic digestion process is thermophilic aerobic digestion (TAD), which is used to produce Class A biosolids.

The thermophilic process requires significantly lower residence times (i.e. solids retention time) than conventional aerobic processes. The OMRR requires the thermophilic process to operate at temperatures greater than 55°Celsius for more than 30 minutes. The process is relatively stable, recovers quickly from minor process upsets, and is not affected by relatively wide variations in outside air temperature. The main issue of thermophilic process with low residence time is that ammonia will accumulate and increase odour. On the other hand, the mesophillic process provides enough holding time for the nitrification process to occur so that little ammonia will accumulate.

4.3.2 Anaerobic Digestion

Anaerobic digestion is a biological process that uses bacteria that function in an oxygen-free environment to convert volatile solids into carbon dioxide, methane, and ammonia. These reactions take place in an enclosed tank that may or may not be heated (U.S. EPA, 2003a). Because the biological activity consumes most of the volatile solids needed for further bacteria growth, microbial activity in the treated sewage sludge is limited. Currently, anaerobic digestion is one of the most widely used treatments for sewage sludge treatment, especially in treatment works with average wastewater flow rates greater than 19,000 cubic meters/day (5 million gallons per day) (U.S. EPA, 2003a).

Anaerobic systems typically reduce bacterial and viral pathogens by 90% or more and volatile solids by 35% to 60%, depending on the nature of the sewage sludge and the system’s operating conditions (U.S. EPA, 2003a).

The primary and thickened waste activated sludge would be digested prior to the dewatering process. Most anaerobic digestion systems are classified as either standard-rate or high-rate systems. Standard-rate systems take place in a simple storage tank with sewage sludge added intermittently. Mixing is not provided in low-rate systems, causing stratification within the digester (NBP, 2005). Under the OMRR, the standard-rate anaerobic systems can be used to produce Class B biosolids and must operate between 15 days at 35°C to 55 °C and 60 days at 20°C.

High-rate systems use a combination of active mixing and carefully elevated temperature control to increase the rate of volatile solids destruction (NBP, 2005). The wastewater residuals treated using high-rate systems are considered Class A when the systems operate at a temperature greater than 50°C for at least 10 consecutive days.

Key advantages of anaerobic include the generation of methane (biogas) which is considered a renewable source of energy, and a reduction in the sludge mass. A disadvantage to using anaerobic digestion is the generation of high concentration sulphides and ammonia, which are odour causing compounds. These odorous compounds could result in an odour issue and possible odour complaints. An additional odour control facility must be constructed because biofiltration technology would not be able to handle the high loads of contaminants,

Although energy recovery is an advantage to using this stabilization method, the amount of energy generated from the WRWWTP would not be sufficient to justify the capital investment for energy recovery from the produced methane. In addition, the operation requirements for energy recovery from methane make it less attractive. For these reasons, digestion gas is often combusted in a flare system without energy recovery. Also, the WRWWTP is a BNR facility which would result in the generation of higher concentrations of ammonia and phosphorus in the supernatant when using anaerobic digestion.

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4.3.3 Composting

Composting is the controlled, aerobic decomposition of organic matter which produces a humus-like material. Sewage sludge which is to be composted is generally mixed with a bulking agent such as wood chips which increases porosity in the sewage sludge, allowing air to more easily pass through the composting material and maintain aerobic conditions (U.S. EPA, 2003a). It is a biological process commonly used to create a marketable end product from various types of organic waste. There are three commonly used methods of composting: windrow, static aerated pile, and In-vessel:

Windrows - Dewatered wastewater solids are mixed with bulking agent and piled in long rows.

Static Aerated Pile - Dewatered cake is mechanically mixed with a bulking agent and stacked into long piles over a bed of pipes through which air is transferred to the composting material.

In-Vessel - A mixture of dewatered wastewater solids and bulking agent is fed into a silo, tunnel, channel, or vessel.

Composting systems typically provide from 18 to 24 days of active composting process followed by 30 to 45 days of compost curing (NBP, 2005).

The In-vessel technology is more suitable than other composting technologies in suburban and urban settings because the system allows for containment and treatment of air to remove odors before release. The requirement for a relatively small amount of land also increases its applicability in these settings over other types of composting. However, a market for use of the resulting product will generally be more readily available in suburban and rural areas rather than urban settings (U.S. EPA, 2000c).

A key advantage to composting is that biosolids compost is safe to use and generally has a high degree of acceptability by the public (U.S. EPA, 2002). In addition, Class A compost can be distributed without restriction and without a land application permit (B.C. Reg. 18/2002). It is said that, compost can be handled more easily than some other biosolids products such as digested sludge (U.S. EPA, 2000c).

A disadvantage to composting is that aerated static pile, windrow and in-vessel composting processes can produce objectionable odors if anaerobic conditions occur and even with aerobic conditions. As an odor control system is an inherent part of a composting facility, the cost of an odor control system can account for up to 50 percent of both capital and operation and maintenance costs (U.S. EPA, 2000c).

Composting can be used successfully to stabilize raw solids and produce a material that meets Class A pathogen reduction requirements. A number of facilities, however, elect to digest solids prior to composting. Potential advantages include reduced odor potential during the composting process and enhanced product quality (NBP, 2005).

Composting is a very attractive stabilization if the possibility to produce Class A biosolids exists.

4.4 Sludge Stabilization Summary and Recommendations

A summary of the recommended long-term and short-term sludge stabilization processes is presented in Table 4-1. In order to meet the sludge stabilization goal of reducing odour, long-term pathogen densities and vector attraction, mesophilic aerobic digestion would the most suitable process for the WRWWTP due to its size and operation. Further investigation would be necessary to determine the technical and economic feasibility of this long-term stabilization method at the WRWWTP.

Thermophilic aerobic digestion requires lower residence times but produces ammonia and increases odour. Anaerobic digestion generates high concentrations of methane, sulphides and ammonia; the removal of these gases could lead to high costs for new treatment facilities. In addition, due to the small size of the WRWWTP, the biogas recovered from the anaerobic process would not yield a favourable return on investment. Composting can be labor intensive or high in cost, require a significant amount of space and generate nuisance odours if treating undigested sludge.

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If long-term stabilization methods are no longer desired, short-term stabilization methods such as lime stabilization could prove to be a cost-effective way of reducing odour and temporarily increasing the stability of the product.

Table 4-1: Summary of Stabilization Technologies

Processes Advantages Disadvantages

Long-Term Stabilization

Aerobic Digestion ‐ Low cost ‐ Low process complexity ‐ Significantly reduces pathogen

and degree of vector attraction

‐ Potential problem with dewatering

‐ Potential reduction of efficiency during winter

‐ Large amounts of space required

‐ Energy Intensive for medium to large facilities

Anaerobic Digestion ‐ Significantly reduces pathogen and degree of vector attraction

‐ When feasible, energy recovery potential

‐ Ideal for medium to large facilities

‐ Potential problem with dewatering

‐ Generation of sulphide and ammonia

‐ Require more advanced odour control system

‐ Large amount of space required

Composting ‐ Class A compost can be distributed with restriction

‐ More publically accepted ‐ Produces a more marketable

product

‐ Require more advanced odour control system

‐ Certain methods are labor intensive

‐ Class B compost are subject to the same restrictions as Class B Biosolids

Short-Term Stabilization

Lime Stabilization ‐ Cost effective ‐ Significant reduction of

bacterial and viral pathogens ‐ Can generate Class B biosolids ‐ Simple and flexible operation ‐ Small footprint required

‐ Potential odour problem due to the release of ammonia and amines

‐ pH must be kept above 11 ‐ Increased volume of biosolids

to be handled ‐ More effective stabilization

method when accompanied with a sludge drying method

4.4.1 Overview of Mesophilic Aerobic Digestion

Mesophilic aerobic digestion has been installed in many WWTPs around U.S., such as Lycoming County WWTP (Montoursville, Pennsylvania), Frackville WWTP (Frackville, Pennsylvania), Waymart WWTP (Waymart, Pennsylvania), Seneca WWTP (Germantown, Maryland), Paris WWTP (Paris,

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Illinois), Rigby WWTP (Rigby, Idaho), Bellefonte WWTP (Bellefonte, Pennsylvania), Madison WWTP (Madison, South Dakota), Honesdale WWTP (Honesdale, Pennsylvania), and Lititz WWTP (Lititz, Pennsylvania). Lycoming County WWTP currently operates a pre-thickened aerobic digester using mechanical thickening (PAD-M) process which was commissioned in June 2012. Waste activated sludge from a sequencing batch reactor (SBR) liquid treatment process is thickened up to 5% solids with a gravity belt thickener and processed in two aerobic digester tanks. The two aerobic digester tanks were retrofitted with an Airbeam Cover aerobic digestion aeration system for temperature and odour control as well as improved volatile solids destruction. Since the entire operations the PAD-M aerobic digestion system is able to sustain a volatile solids destruction ranging from 39% to 58% as well as provide excellent pH control ranging from 6.5 to 7.0 indicating excellent odor control. More detail on the aerobic digestion at Lycoming County WWTP can be found from the article in Appendix C.

Sludge stabilization using aerobic digestion for this project will require operating two (2) tanks of equal size in series. Each tank will have a footprint around 19 m x 19 m with a SRT of 20 days. The two tanks will be enclosed with Airbeam Cover. Aeration will be supplied to the tanks, and the exhaust air can be sent to the biofilter if it requires further treatment. The capital cost is estimated to be around $ 2.0 million, along with an annual operating cost of between $ 0.5 – $ 0.75 million.

Currently, WRWWTP removes phosphorous from wastewater biologically, and most of the phosphorous remains in the dewatered sludge. Sludge stabilization using aerobic or anaerobic digestion will cause the re-release of phosporous to the centrate. It will be required to chemically precipitate the elevated phosphorous after the digestion. It has been proven that the dosing of ferric chloride or aluminum sulphate successfully resulted in a reduction in the phosphorus concentration of the centrate. Further investigation would be required to determine to most suitable chemical and dosing system.

5. Disposal of Dewatered Sludge

5.1 Land Application of Biosolids

The land application of biosolids is an excellent way to recycle wastewater solids as it returns valuable nutrients to the soil and enhances conditions for vegetative growth. Biosolids contain a high nutrient and organic matter content and can be beneficially applied to land as a fertilizer or soil conditioner.

Under the OMRR, the wastewater residuals are classified according to quality and process criteria:

- Class A biosolids - Class B biosolids - Biosolids growing medium (Class A or B)

Class A biosolids represent the highest quality biosolids achievable and comply with the most stringent standards which allows for more liberal distribution; whereas, Class B biosolids are subject to less stringent requirements and to more land application restrictions. Biosolids growing medium (BGM) is a fabricated soil product derived from the combination of biosolids with other organic and inorganic feedstock material. BGM can be fabricated with Class A or B biosolids which meet the requirements of the OMRR.

WRWWTP currently produces Class B biosolids for land application. It is the objective of the WRWWTP to:

to improve the quality of biosololids to reduce odours, pathogen density and vector attraction; and

explore the feasibility to upgrade the biosolids quality from Class B to Class A.

Recommendations to achieve each objective are described below.

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5.1.1 The Improvement of Class B Biosolids Quality

The WRWWTP is currently producing Class B Biosolids. However, long-term stabilization of their residuals would result in a reduction of odours as well as an improved quality in the Biosolids. The stabilization processes that would meet the requirements of the OMRR and improve the quality of biosolids are:

Aerobic digestion; Anaerobic digestion; and Composting.

As recommended in Section 3.4, aerobic digestion would improve the quality of the Class B biosolids while being the most effective method to reduce odour during the biosolids handling.

5.1.2 Upgrading from Class B to Class A Biosolids

The wastewater residuals of the WRWWTP meet the quality criteria for Class A biosolids. However, in order for the WRWWTP residuals to meet Class A biosolids requirements, a process which further reduces pathogens, vector attraction and fecal coliforms content must be implemented. The stabilization processes that would meet the requirements under the OMRR and meet the WRWWTP goals of long-term stabilization and odour reduction of dewatered sludge are:

Thermophilic aerobic digestion Thermophilic anaerobic digestion; and Composting.

Thermophilic aerobic and anarerobic digestion require heating and generate odourous compounds such as ammonia and hydrogen sulphide which creates difficulties for WRWWTP to implement this approach. Composting can result in the nuisance odours as well.

Although Class A biosolids allow for more opportunity for land application, the production of high quality Class B biosolids is expected to be more cost effective and adequately increase the opportunity for land use as well. Therefore, it is not recommended that the WRWWTP upgrade the biosolids from Class B to Class A at this time. Instead, they should strive for Class B biosolids with the fecal coliform content under 1000 MPN g-1 dw, This goal may be possible with the combination of stabilization methods discussed along with additional drying during storage prior to land application.

5.2 Sludge Disposal Methods

Incineration is an environmentally and technically superior method of waste disposal, offering reliability, safety, and efficiency. At the same time, it is highly controversial and expensive. In previous decades, landfills were primarily used for waste disposal, allowing nature to take its course, eventually reducing the end volume toxicity of the wastes. However, because of increasingly stringent environmental regulations concerning air quality, landfills, and groundwater contamination, along with the decreasing availability of land for the encapsulation of wastes, incineration has become the desired disposal method for municipalities and industries. In addition, the incineration technology is constantly undergoing revisions in order to meet tougher environmental standards; these technological advances include those that increase efficiency, and those that improve emission control.

Incineration thermally decomposes matter through oxidation, thereby reducing and minimizing the wastes. It can be applied to industrial, municipal, and hazardous wastes, provided that they contain organic material since it is primarily organic substances that can undergo and sustain thermal degradation. After incineration, wastes are converted to CO2, CO, water, and inert ash. The volume of the ash is significantly lower than that of the original biosolids.

Wet sludge cannot be incinerated because of the large amounts of fuel that would be needed. However, a filter cake of sludge or a well-thickened sludge may be burned. If the solids concentration can be raised to roughly 30 to 40 per cent by weight, the heat of combustion of the organic material will about match the heat of vaporization of the water, thus minimizing or eliminating the need for fuel

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except for start-up. If solid wastes are being incinerated, their fuel value may be enough to compensate for adding sludge that is not very dry.

The existing dewatering process at WRWWTP is only able to achieve solid content around 20%, and the sludge is not suitable for incineration application. This solid content is very low for having self-sustainable combustion. Additional sludge drying process is required before it can be considered for incineration. Furthermore the incineration of digested solids is not as efficient as that of raw residuals which contain a greater heat value5.

Depending on the composition of the initial waste, compounds containing halogens, metals (e.g. mercury), nitrogen, and sulfur may be produced. These compounds, along with CO, are deleterious to the atmosphere, and highly regulated. Presently, the destruction efficiency for these hazardous wastes must be 99.9999 %. Thus, to meet regulations, incinerators need to be equipped with secondary treatment such as scrubbers, filtration units, and membranes.

Facilities electing to use incineration must obtain a Clean Air Act permit and meet stringent air quality standards. Due to the high costs involved with incineration and air pollution control equipment, only large municipalities can afford this option. For WRWWTP, it is suggested that the sludge be transported to an offsite incineration facility if the sludge can meet the incineration requirements with further drying. A third party incineration company would have to be located in order for more information on the tipping fees and transportation costs. This option will be further assessed upon WRWWTP request with additional information provided.

6. Conclusion

6.1 Preliminary Field Odour Study

Based on the field measurements, observations and sampling results analysis, below is a summary of our findings and conclusions

1. The sludge loading facility and most of the process area are operating at slightly positive pressure

2. The H2S values measured during the preliminary sampling program are under 5 ppm (6,965 μg/m3) with the exception on September 13th, 2013 when was recorded at 13 ppm (18,110 μg/m3)

3. The instantaneous H2S concentrations at the selected receptors were measured between 0.001 and 0.057 ppm (1 – 79 μg/m3)

4. Spots at biofilter outlet were identified were the H2S concentration was recorded almost equal to the biofilter inlet concentration

5. The current biofilter is not supplied with a primary humidification system 6. The strategy and operation of the secondary humidification system could be optimized for

improved biofilter operation 7. Air emissions were observed between biofilter vessel and internal liner 8. No TRS concentrations were detected at the selected receptors outside the WWTP. TRS

concentrations inside WWTP were recorded between 290 – 3,100 μg/m3 (0.17 – 2.05 ppm)

9. During the preliminary sampling program the H2S concentrations were below the previous records ( Appendix D)

6.1.1 Emission Standards and Guidelines

The TRS sampling results indicated that no reduced sulphur compounds could be identified at the sensitive receptor locations; however, H2S concentrations were detected during the monitoring event. Since the province of British Columbia does not currently have an ambient air quality guideline specifically for hydrogen sulphide, the Ontario 10 minute-average standard for hydrogen sulphide was used for a high-level assessment of regulatory compliance. The Ontario H2S 10 minute-average guideline of 13 μg/m3 (0.009 ppm) was exceeded on one (1) occasion, September 13th, 2013 at

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Receptor R-3, as the truck drove by. The concentration recorded during the sampling event was 0.057 ppm (79 μg/m3) which is significantly lower than the British Columbia short-term exposure limit of 10 ppm (13,930 μg/m3). When the H2S concentration is below 1 ppm, there is a low risk of adverse health effects to the surrounding residents due to H2S generated from the WRWWTP. Further monitoring and investigation is required to evaluate the continuous H2S levels surrounding the facility.

6.2 Sludge Stabilization

The stabilization of the wastewater sludge significantly reduces the odours as well as produces a higher quality of biosolids for land application purposes. AECOM assessed various wastewater residuals stabilization methods that would temporarily and permanently stabilize the sludge. In order to produce a long-term or permanent stabilized sludge, the biological digestion processes, namely aerobic and anaerobic digestion, proved to be the most effective and recommended. Aerobic digestion would best achieve the WWTP’s goals at lower costs. It is estimated that the capital cost is estimated to be around $ 2.0 million, along with an annual operating cost of between $ 0.5 and $ 0.75 million. Further investigation would be required to determine the technical and economic feasibility this stabilization method.

7. Recommendations

AECOM recommendations for the odour mitigation and sludge stabilization are provided below

7.1 Recommendations for Immediate Actions

The current odour control system be balanced and operated at the design parameters.

The operating strategy of the existing humidification system should be reviewed and adjusted to improve the biofilter performance.

Preliminary design for a primary humidification unit at the biofilter inlet to determine scope and cost. The primary humidification system would help to maintain a consistent moisture content of the air stream to enhance the growth of the microorganisms that degrade the odourous compounds; thereby increasing the vessels treatment efficiency. The approximate cost of the system is between $80,000 and $100,000.

Eliminate the air emissions between biofilter vessel and internal liner.

Investigate alternatives to further reduce odours from the hauling of biosolids, such as implementing a better seal for the truck cover and adding Bioxide®, or other similar proprietary chemical, to the dewatered sludge.

Re-acclimate the existing media and add a nutrient system to promote and enhance microbial growth.

The odour control system should be adjusted to provide negative pressure inside some main process areas, such as, the sludge handling building.

7.2 Recommendations for Subsequent Actions

Continue to evaluate the WWTP overall operation with the goal of reducing foul air emissions at various process steps.

pH measuring devices should be installed at the sump of the inlet plenum to monitor the media performance.

If possible, cover the open process areas identified to generate H2S and odour emissions.

The existing media should be re-blended to incorporate a larger percentage of the course wood chips and to produce a uniform media density.

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WRWWTP should pursue the production of improved Class B biosolids as a cost effective approach to in achieve their goal of a stabilized and less odour offensive product.

WRWWTP continue to optimize the process operations to consistently reduce the hydrogen sulphide content and increase the production of volatile fatty acids.

In order to validate odour control system performance, develop and implement an odour sampling program following the balancing and optimization of the current odour control system.

7.3 Recommendations for Further Investigation

To improve the quality of the WRWWTP’s biosolids, the WRWWTP should further investigate the long-term stabilization method that includes aerobic digestion to significantly reduce the odour generated by the biosolids hauling operation.

Short-term stabilization methods such as lime stabilization should be further investigated to determine if short-term stabilization can meet the goals of the RDCO.

Investigate the feasibility and social-economic benefits to cover the biofilter and install a stack for better dispersion of the emissions.

Following implementation biofilter improvements and the re-balancing of the foul air extraction system, it is recommended that the odour control system capacity be assessed to determine whether the capacity should be further increased to mitigate the odour emissions.

This letter report fulfills AECOM’s current scope of work for the Westside Regional Wastewater Treatment Plant Odour Mitigation and Foul Air Assessment. We hope this will meet your current requirements, and if you have any questions please do not hesitate to contact us.

Sincerely,

Alex Carciumaru, P.Eng. Manager Air Quality Engineering [email protected]

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8. References

Alberta Environment. 2013. Alberta Ambient Air Quality Objectives. http://environment.gov.ab.ca/info/library/5726.pdf

AnnMadge Acquiston, B., Reimers, R.S., Smith, J.E. & Pillai, S.D. 2006. Factors Affecting Disinfection and Stabilization of Sewage Sludge. Proceedings of the Water Environment Federation, WEFTEC 2006: Session 61 through Session 70, pp. 5345-5361(17). Water Environment.

British Columbia Ministry of Environment. 2013. British Columbia Ambient Air Quality Objectives. http://www.bcairquality.ca/reports/pdfs/aqotable.pdf

British Columbia Ministry of Environment [B.C. Reg. 18/2002]. 2002. Environmental Management Act and Public Health Act: Organic Matter Recycling Regulation. British Columbia Regulation 18, 2002.

Environment Canada. 2013 . Weather: Kelowna, BC. http://weather.gc.ca/city/pages/bc-48_metric_e.html

Gouvernement du Québec. 2013. Règlement sur l'assainissement de l'atmosphère: Loi sur la qualité de l'environnement. http://www2.publicationsduquebec.gouv.qc.ca/dynamicSearch/telecharge.php?type=2&file=//Q_2/Q2R4_1.htm

Government of Manitoba. 2005. Manitoba Ambient Air Quality Criteria. http://www.gov.mb.ca/conservation/envprograms/airquality/pdf/criteria_table_update_july_2005.pdf

National Biosolids Partnership. 2005. National Manual Of Good Practice For Biosolids: Chapter 4 – Solids Stabilization Systems. http://www.wef.org/Biosolids/page.aspx?id=7767.

Ontario Ministry of Environment. 2012. Ontario’s Ambient Air Quality Criteria. Document No: PIBS # 6570e01. http://www.ene.gov.on.ca/stdprodconsume/groups/lr/@ene/@resources/documents/resource/std01_079182.pdf

Saskatchewan Ministry of Environment. 2012. Air Monitoring Guideline for Saskatchewan. Regina, Saskatchewan. Document No. TRB001

United States Environmental Protection Agency [U.S. EPA]. 2006. Biosolids Technology Fact Sheet: Heat Drying, EPA 832-F-06-029, U.S. EPA, Washington D.C.

U.S. EPA. 2003a. Environmental Regulations and Technology: Control of Pathogens and Vector Attraction in Sewage Sludge, Report No.:EPA/625/R-92/013, U.S. EPA, Washington D.C.

U.S. EPA . 2003b. Biosolids Technology Fact Sheet: Use of Incineration for Biosolids Management, EPA 832-F-03-013, U.S. EPA, Washington D.C.

U.S. EPA. 2002. Biosolids Technology Fact Sheet: Use of Composting of Biosolids Management, EPA 832-F-02-0524, U.S. EPA, Washington D.C.

U.S. EPA. 2000a. Biosolids Technology Fact Sheet: Alkaline Stabilization of Biosolids, EPA 832-F-00-052, U.S. EPA, Washington D.C.

U.S. EPA. 2000b. Biosolids and Residuals Management Fact Sheet: Odor Control in Biosolids Management, EPA 832-F-00-067, U.S. EPA, Washington D.C.

U.S. EPA. 2000c. Biosolids Fact Sheet: In-Vessel Composting of Biosolids, EPA 832-F-00-061, U.S. EPA, Washington D.C.

WorkSafe Alberta. 2010. Workplace health and safety Bulletin: Hydrogen Sulphide at the Work Site. http://humanservices.alberta.ca/documents/whs-pub-ch029.pdf

WorkSafe BC (the Workers’ Compensation Board of BC). 2013. Guideline Part 5: Table of exposure limits for chemical and biological substances. http://www2.worksafebc.com/publications/ohsregulation/GuidelinePart5.asp#SectionNumber:G5.48-1

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WorkSafe BC (the Workers’ Compensation Board of BC). 2010. Hydrogen Sulphide in Industry. http://www.worksafebc.com/publications/health_and_safety/by_topic/assets/pdf/hydrogen_sulfide.pdf

9. Attachments

Figure 1: Hydrogen Sulphide Monitoring Locations

Figure 2: Total Reduced Sulphur Sampling Locations

Appendix A: Laboratory Sampling Results

Appendix B: Sludge Stabilization Comparative Analysis

Appendix C: Aerobic Digestion Installation Example

Appendix D: Field Notes

Appendix E: Wind Conditions

Figure 1:

Hydrogen Sulphide Monitoring Locations

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Figure 2:

Total Reduced Sulphurs Sampling Locations

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Residential N

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ampling Locations

Appendix A:

Laboratory Analysis Results

2655 Park Center Dr., Suite A Simi Valley, CA 93065 T: +1 805 526 7161 F: +1 805 526 7270 www.alsglobal.com

LABORATORY REPORT October 9, 2013 Stephen Horsman AECOM 3275 Lakeshore Road Suite 201 Kelowna, BC V1W 3S9 Dear Stephen: Enclosed are the results of the samples submitted to our laboratory on September 16, 2013. For your reference, these analyses have been assigned our service request number P1304105. Please note that this report was revised to include a chain of custody received on October 4, 2013, as well as edit the sample ID names, and sampling date/times. No data was altered in this revision. All analyses were performed according to our laboratory’s NELAP and DoD-ELAP-approved quality assurance program. The test results meet requirements of the current NELAP and DoD-ELAP standards, where applicable, and except as noted in the laboratory case narrative provided. For a specific list of NELAP and DoD-ELAP-accredited analytes, refer to the certifications section at www.alsglobal.com. Results are intended to be considered in their entirety and apply only to the samples analyzed and reported herein. If you have any questions, please call me at (805) 526-7161. Respectfully submitted, ALS | Environmental Samantha Henningsen Project Manager

R I G H T S O L U T I O N S | R I G H T P A R T N E R

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http://www.alsglobal.com/


samantha.henningsen

Samantha


Client: AECOM Service Request No: P1304105 _______________________________________________________________________________

CASE NARRATIVE

The samples were received intact under chain of custody on September 16, 2013 and were stored in accordance with the analytical method requirements. Please refer to the sample acceptance check form for additional information. The results reported herein are applicable only to the condition of the samples at the time of sample receipt. Sulfur Analysis The samples were analyzed for twenty sulfur compounds per ASTM D 5504-08 using a gas chromatograph equipped with a sulfur chemiluminescence detector (SCD). All compounds with the exception of hydrogen sulfide and carbonyl sulfide are quantitated against the initial calibration curve for methyl mercaptan. This method is not included on the laboratory’s NELAP, DoD-ELAP, or AIHA-LAP scope of accreditation. ______________________________________________________________________________________ The results of analyses are given in the attached laboratory report. All results are intended to be considered in their entirety, and ALS Environmental (ALS) is not responsible for utilization of less than the complete report. Use of ALS Environmental (ALS)’s Name. Client shall not use ALS’s name or trademark in any marketing or reporting materials, press releases or in any other manner (“Materials”) whatsoever and shall not attribute to ALS any test result, tolerance or specification derived from ALS’s data (“Attribution”) without ALS’s prior written consent, which may be withheld by ALS for any reason in its sole discretion. To request ALS’s consent, Client shall provide copies of the proposed Materials or Attribution and describe in writing Client’s proposed use of such Materials or Attribution. If ALS has not provided written approval of the Materials or Attribution within ten (10) days of receipt from Client, Client’s request to use ALS’s name or trademark in any Materials or Attribution shall be deemed denied. ALS may, in its discretion, reasonably charge Client for its time in reviewing Materials or Attribution requests. Client acknowledges and agrees that the unauthorized use of ALS’s name or trademark may cause ALS to incur irreparable harm for which the recovery of money damages will be inadequate. Accordingly, Client acknowledges and agrees that a violation shall justify preliminary injunctive relief. For questions contact the laboratory.


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Certifications, Accreditations, and Registrations

Agency Web Site Number

AIHA http://www.aihaaccreditedlabs.org 101661

Arizona DHS http://www.azdhs.gov/lab/license/env.htm AZ0694

DoD ELAP http://www.pjlabs.com/search-accredited-labs L11-203

Florida DOH (NELAP)

http://www.doh.state.fl.us/lab/EnvLabCert/WaterCert.htm E871020

Maine DHHS http://www.maine.gov/dhhs/mecdc/environmental-health/water/dwp-services/labcert/labcert.htm

2012039

Minnesota DOH (NELAP)

http://www.health.state.mn.us/accreditation 581572

New Jersey DEP (NELAP)

http://www.nj.gov/dep/oqa/ CA009

New York DOH (NELAP)

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Pennsylvania DEP http://www.depweb.state.pa.us/labs 68-03307

(Registration) Texas CEQ (NELAP)

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13-4 Utah DOH (NELAP)

http://www.health.utah.gov/lab/labimp/certification/index.html CA01627201

3-3

Washington DOE http://www.ecy.wa.gov/programs/eap/labs/lab-accreditation.html C946

Analyses were performed according to our laboratory’s NELAP and DoD-ELAP approved quality assurance program. A complete listing of specific NELAP and DoD-ELAP certified analytes can be found in the certifications section at www.alsglobal.com, or at the accreditation body’s website. Each of the certifications listed above have an explicit Scope of Accreditation that applies to specific matrices/methods/analytes; therefore, please contact the laboratory for information corresponding to a particular certification.


3 of 17


http://www.aihaaccreditedlabs.org/

http://www.azdhs.gov/lab/license/env.htm

http://www.pjlabs.com/search-accredited-labs

http://www.doh.state.fl.us/lab/EnvLabCert/WaterCert.htm

http://www.maine.gov/dhhs/mecdc/environmental-health/water/dwp-services/labcert/labcert.htm


http://www.health.state.mn.us/accreditation

http://www.nj.gov/dep/oqa/

http://www.wadsworth.org/labcert/elap/elap.html



http://www.depweb.state.pa.us/labs

http://www.tceq.texas.gov/field/qa/env_lab_accreditation.html

http://www.health.utah.gov/lab/labimp/certification/index.html

http://www.ecy.wa.gov/programs/eap/labs/lab-accreditation.html


P1304105_Detail Summary_1309261604_RB.xls - DETAIL SUMMARY

Client: AECOM Service Request: P1304105

Date Received: 9/16/2013Time Received: 09:25

Client Sample ID Lab Code MatrixDate

CollectedTime

CollectedContainer

IDPi1

(psig)Pf1

(psig)

Sample #1 WWTP Sludge Loading Inside P1304105-001 Air 9/9/2013 13:34 AS00525 -0.58 0.57 X

Sample #2 WWTP Biofilter Inlet Port P1304105-002 Air 9/10/2013 09:48 AS00119 -0.37 0.54 X

Sample #3 WWTP Biofilter Mid-Center P1304105-003 Air 9/10/2013 09:50 AS00205 -0.41 0.74 X

Sample #5 WWTP Sludge Loading Inside P1304105-004 Air 9/13/2013 17:05 AS00155 -5.42 0.56 X

Sample #4 R1 Whitworth Liftstation P1304105-005 Air 9/10/2013 09:15 AS00531 -0.70 0.64 X

Sample #6 R3 While Loaded Sludge Truck Passes P1304105-006 Air 9/13/2013 09:32 AS00244 -8.11 0.47 X

ALS ENVIRONMENTAL

DETAIL SUMMARY REPORT

AST

M D

5504

-08

- Sul

fur C

an

4 of 17

P1304105_Detail Summary_1309261604_RB.xls - DETAIL SUMMARY




CollectedTime

CollectedContainer

IDPi1

(psig)Pf1

(psig)

ALS ENVIRONMENTAL


AST

M D

5504

-08

- Sul

fur C

an

5 of 17

Air - Chain of Custody Record & Analytical Service Request 2655 Park Center Drive, Suite A

Simi Valley, California 93065

Phone (805) 526-7161 Requested Turnaround Time in Business Days (Surcharges) please circle

Page _1 __ of _1 __

ALS Project No.

Fax(805)526-7270 1 Day(100%) 2Day(75%) 3Day(50%) 4Day(35%) 5Day(25%) 10Day-Standard

ALS Contact: Company Name & Address (Reporting Information) Project Name

' AECOM ' RDCO Odor Study Analysis Method Suite 201-3725 Lakeshore Road Project Number

Kelowna, British Columbia, V1W 3S9 Canada 60306094 Project Manager P.O. # I Billing Information

Stephen Horsman Comments Phone Fax e.g. Actual

250-762-3727 250-762-7789 Preservative or I

Email Address for Result Reporting Sampler (Print & Sign) (kqj;{ specific instructions

[email protected] Chr.·& Y11i/ler Laboratory Date Time

Canister ID Flow Controller ID Canister Canister Client Sample ID (Bar code#- (Barcode #- Start Pressure End Pressure Sample

ID Number Collected Collected AC, SC, etc.) FC#) "Hg "Hg/pslg Volume

Sample #1 WWTP Sludge Loading Inside 9/9/2013 1:34 pm 14660

Sample #2 WWTP Biofilter Inlet Port 9/10/2013 9:48 am 5011

Sample #3 WWTP Biofilter Mid-Center 9/10/2013 9:50 am 12361

Sample #4 R1 Whitworth Liftstation 9/10/2013 5:05 pm 14666

Sample #5 WWTP Sludge Loading Inside 9/13/2013 9:15 am 5039

Sample #6 R3 While Loaded Sludge Truck Passes 9/13/2013 9:32 am 12964

Report Tier Levels - please select

Tier I - Results (Default if not specified) __ Tier Ill (Results+ QC & Calibration Summaries) __ EDD required Yes I No Project Requirements Tier II (Results + QC Summaries) -- Tier IV (Data Validation Package) 10% Surcharge __ Type: Units: (MRLs, QAPP)

Relinquished by: (Signature) Date: Time: Received by: (Signature) Date: Time:

Relinquished by: (Signature) Date: Time: Received by: (Signature) Date: Time: Cooler I Blank Temperature __ •c

6 of 17

10/9/2013 2:15 PMP1304105_AECOM_.xls - Page 1 of 1

ALS EnvironmentalSample Acceptance Check Form

Client: AECOM Work order: P1304105Project:Sample(s) received on: 9/16/2013 Date opened: 9/16/2013 by: MZAMORA

Note: This form is used for all samples received by ALS. The use of this form for custody seals is strictly meant to indicate presence/absence and not as an indication of

compliance or nonconformity. Thermal preservation and pH will only be evaluated either at the request of the client and/or as required by the method/SOP.Yes No N/A

1 Were sample containers properly marked with client sample ID? 2 Container(s) supplied by ALS? 3 Did sample containers arrive in good condition? 4 Were chain-of-custody papers used and filled out? 5 Did sample container labels and/or tags agree with custody papers? 6 Was sample volume received adequate for analysis? 7 Are samples within specified holding times? 8 Was proper temperature (thermal preservation) of cooler at receipt adhered to?

9 Was a trip blank received?

10 Were custody seals on outside of cooler/Box? Location of seal(s)? Sealing Lid?

Were signature and date included? Were seals intact? Were custody seals on outside of sample container?

Location of seal(s)? Sealing Lid? Were signature and date included? Were seals intact?

11 Is there a client indication that the submitted samples are pH preserved? Were VOA vials checked for presence/absence of air bubbles?

12 Tubes: Are the tubes capped and intact?

Do they contain moisture? 13 Badges: Are the badges properly capped and intact?

Are dual bed badges separated and individually capped and intact?

Lab Sample ID Container Required Received Adjusted VOA HeadspaceDescription pH * pH pH (Presence/Absence) Comments

6.0 L Silonite Can6.0 L Silonite Can6.0 L Silonite Can6.0 L Silonite Can6.0 L Silonite Can6.0 L Silonite Can

Missing chain of custody form

RSK - MEEPP, HCL (pH<2); RSK - CO2, (pH 5-8); Sulfur (pH>4)

P1304105-006.01

Explain any discrepancies: (include lab sample ID numbers):

Do containers have appropriate preservation, according to method/SOP or Client specified information?

Does the client/method/SOP require that the analyst check the sample pH and if necessary alter it?

Receipt / Preservation

P1304105-001.01P1304105-002.01P1304105-003.01P1304105-004.01P1304105-005.01

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20SULFUR.XLS - Page No.:P1304105R_ASTM5504_1309200846_RD.xls - Sample

ALS ENVIRONMENTAL

RESULTS OF ANALYSISPage 1 of 1

Client: AECOMClient Sample ID: Sample #1 WWTP Sludge Loading Inside ALS Project ID: P1304105Client Project ID: RDCO Odor Study ALS Sample ID: P1304105-001

Test Code: ASTM D 5504-08 Date Collected: 9/9/13Instrument ID: Agilent 6890A/GC13/SCD Time Collected: 13:34Analyst: Mike Conejo Date Received: 9/16/13Sample Type: 6.0 L Silonite Canister Date Analyzed: 9/17/13Test Notes: Time Analyzed: 15:31Container ID: AS00525 Volume(s) Analyzed: 1.0 ml(s)

Initial Pressure (psig): -0.58 Final Pressure (psig): 0.57

Canister Dilution Factor: 1.08

CAS # Compound Result MRL Result MRL Dataµg/m³ µg/m³ ppbV ppbV Qualifier

7783-06-4 Hydrogen Sulfide 190 7.5 130 5.4 463-58-1 Carbonyl Sulfide ND 13 ND 5.4 74-93-1 Methyl Mercaptan 53 11 27 5.4 75-08-1 Ethyl Mercaptan ND 14 ND 5.4 75-18-3 Dimethyl Sulfide 19 14 7.4 5.4 75-15-0 Carbon Disulfide ND 8.4 ND 2.7 75-33-2 Isopropyl Mercaptan ND 17 ND 5.4 75-66-1 tert-Butyl Mercaptan ND 20 ND 5.4 107-03-9 n-Propyl Mercaptan ND 17 ND 5.4 624-89-5 Ethyl Methyl Sulfide ND 17 ND 5.4 110-02-1 Thiophene ND 19 ND 5.4 513-44-0 Isobutyl Mercaptan ND 20 ND 5.4 352-93-2 Diethyl Sulfide ND 20 ND 5.4 109-79-5 n-Butyl Mercaptan ND 20 ND 5.4 624-92-0 Dimethyl Disulfide 27 10 6.9 2.7 616-44-4 3-Methylthiophene ND 22 ND 5.4 110-01-0 Tetrahydrothiophene ND 19 ND 5.4 638-02-8 2,5-Dimethylthiophene ND 25 ND 5.4 872-55-9 2-Ethylthiophene ND 25 ND 5.4 110-81-6 Diethyl Disulfide ND 13 ND 2.7

ND = Compound was analyzed for, but not detected above the laboratory reporting limit.MRL = Method Reporting Limit - The minimum quantity of a target analyte that can be confidently determined by the referenced method.

8 of 17

20SULFUR.XLS - Page No.:P1304105R_ASTM5504_1309200846_RD.xls - Sample (2)

ALS ENVIRONMENTAL


Client: AECOMClient Sample ID: Sample #2 WWTP Biofilter Inlet Port ALS Project ID: P1304105Client Project ID: RDCO Odor Study ALS Sample ID: P1304105-002





7783-06-4 Hydrogen Sulfide 2,500 7.4 1,800 5.3 463-58-1 Carbonyl Sulfide ND 13 ND 5.3 74-93-1 Methyl Mercaptan 400 10 200 5.3 75-08-1 Ethyl Mercaptan ND 13 ND 5.3 75-18-3 Dimethyl Sulfide 77 13 30 5.3 75-15-0 Carbon Disulfide ND 8.2 ND 2.7 75-33-2 Isopropyl Mercaptan ND 17 ND 5.3 75-66-1 tert-Butyl Mercaptan ND 20 ND 5.3 107-03-9 n-Propyl Mercaptan ND 17 ND 5.3 624-89-5 Ethyl Methyl Sulfide ND 17 ND 5.3 110-02-1 Thiophene ND 18 ND 5.3 513-44-0 Isobutyl Mercaptan ND 20 ND 5.3 352-93-2 Diethyl Sulfide ND 20 ND 5.3 109-79-5 n-Butyl Mercaptan ND 20 ND 5.3 624-92-0 Dimethyl Disulfide 68 10 18 2.7 616-44-4 3-Methylthiophene ND 21 ND 5.3 110-01-0 Tetrahydrothiophene ND 19 ND 5.3 638-02-8 2,5-Dimethylthiophene ND 24 ND 5.3 872-55-9 2-Ethylthiophene ND 24 ND 5.3 110-81-6 Diethyl Disulfide ND 13 ND 2.7


9 of 17


ALS ENVIRONMENTAL


Client: AECOMClient Sample ID: Sample #3 WWTP Biofilter Mid-Center ALS Project ID: P1304105Client Project ID: RDCO Odor Study ALS Sample ID: P1304105-003





7783-06-4 Hydrogen Sulfide 790 7.5 570 5.4 463-58-1 Carbonyl Sulfide ND 13 ND 5.4 74-93-1 Methyl Mercaptan 160 11 81 5.4 75-08-1 Ethyl Mercaptan ND 14 ND 5.4 75-18-3 Dimethyl Sulfide 31 14 12 5.4 75-15-0 Carbon Disulfide ND 8.4 ND 2.7 75-33-2 Isopropyl Mercaptan ND 17 ND 5.4 75-66-1 tert-Butyl Mercaptan ND 20 ND 5.4 107-03-9 n-Propyl Mercaptan ND 17 ND 5.4 624-89-5 Ethyl Methyl Sulfide ND 17 ND 5.4 110-02-1 Thiophene ND 19 ND 5.4 513-44-0 Isobutyl Mercaptan ND 20 ND 5.4 352-93-2 Diethyl Sulfide ND 20 ND 5.4 109-79-5 n-Butyl Mercaptan ND 20 ND 5.4 624-92-0 Dimethyl Disulfide ND 10 ND 2.7 616-44-4 3-Methylthiophene ND 22 ND 5.4 110-01-0 Tetrahydrothiophene ND 19 ND 5.4 638-02-8 2,5-Dimethylthiophene ND 25 ND 5.4 872-55-9 2-Ethylthiophene ND 25 ND 5.4 110-81-6 Diethyl Disulfide ND 13 ND 2.7


10 of 17


ALS ENVIRONMENTAL


Client: AECOMClient Sample ID: Sample #5 WWTP Sludge Loading Inside ALS Project ID: P1304105Client Project ID: RDCO Odor Study ALS Sample ID: P1304105-004





7783-06-4 Hydrogen Sulfide 27,000 11 20,000 8.2 463-58-1 Carbonyl Sulfide ND 20 ND 8.2 74-93-1 Methyl Mercaptan 23,000 16 12,000 8.2 75-08-1 Ethyl Mercaptan 27 21 11 8.2 75-18-3 Dimethyl Sulfide 3,200 21 1,200 8.2 75-15-0 Carbon Disulfide ND 13 ND 4.1 75-33-2 Isopropyl Mercaptan ND 26 ND 8.2 75-66-1 tert-Butyl Mercaptan ND 30 ND 8.2 107-03-9 n-Propyl Mercaptan ND 26 ND 8.2 624-89-5 Ethyl Methyl Sulfide ND 26 ND 8.2 110-02-1 Thiophene ND 28 ND 8.2 513-44-0 Isobutyl Mercaptan ND 30 ND 8.2 352-93-2 Diethyl Sulfide ND 30 ND 8.2 109-79-5 n-Butyl Mercaptan ND 30 ND 8.2 624-92-0 Dimethyl Disulfide 1,700 16 430 4.1 616-44-4 3-Methylthiophene ND 33 ND 8.2 110-01-0 Tetrahydrothiophene ND 30 ND 8.2 638-02-8 2,5-Dimethylthiophene ND 38 ND 8.2 872-55-9 2-Ethylthiophene ND 38 ND 8.2 110-81-6 Diethyl Disulfide ND 20 ND 4.1


11 of 17


ALS ENVIRONMENTAL


Client: AECOMClient Sample ID: Sample #4 R1 Whitworth Liftstation ALS Project ID: P1304105Client Project ID: RDCO Odor Study ALS Sample ID: P1304105-005





7783-06-4 Hydrogen Sulfide ND 7.7 ND 5.5 463-58-1 Carbonyl Sulfide ND 14 ND 5.5 74-93-1 Methyl Mercaptan ND 11 ND 5.5 75-08-1 Ethyl Mercaptan ND 14 ND 5.5 75-18-3 Dimethyl Sulfide ND 14 ND 5.5 75-15-0 Carbon Disulfide ND 8.6 ND 2.8 75-33-2 Isopropyl Mercaptan ND 17 ND 5.5 75-66-1 tert-Butyl Mercaptan ND 20 ND 5.5 107-03-9 n-Propyl Mercaptan ND 17 ND 5.5 624-89-5 Ethyl Methyl Sulfide ND 17 ND 5.5 110-02-1 Thiophene ND 19 ND 5.5 513-44-0 Isobutyl Mercaptan ND 20 ND 5.5 352-93-2 Diethyl Sulfide ND 20 ND 5.5 109-79-5 n-Butyl Mercaptan ND 20 ND 5.5 624-92-0 Dimethyl Disulfide ND 11 ND 2.8 616-44-4 3-Methylthiophene ND 22 ND 5.5 110-01-0 Tetrahydrothiophene ND 20 ND 5.5 638-02-8 2,5-Dimethylthiophene ND 25 ND 5.5 872-55-9 2-Ethylthiophene ND 25 ND 5.5 110-81-6 Diethyl Disulfide ND 14 ND 2.8


12 of 17


ALS ENVIRONMENTAL


Client: AECOMClient Sample ID: Sample #6 R3 While Loaded Sludge Truck Passes ALS Project ID: P1304105Client Project ID: RDCO Odor Study ALS Sample ID: P1304105-006





7783-06-4 Hydrogen Sulfide ND 16 ND 12 463-58-1 Carbonyl Sulfide ND 28 ND 12 74-93-1 Methyl Mercaptan ND 23 ND 12 75-08-1 Ethyl Mercaptan ND 29 ND 12 75-18-3 Dimethyl Sulfide ND 29 ND 12 75-15-0 Carbon Disulfide ND 18 ND 5.8 75-33-2 Isopropyl Mercaptan ND 36 ND 12 75-66-1 tert-Butyl Mercaptan ND 42 ND 12 107-03-9 n-Propyl Mercaptan ND 36 ND 12 624-89-5 Ethyl Methyl Sulfide ND 36 ND 12 110-02-1 Thiophene ND 40 ND 12 513-44-0 Isobutyl Mercaptan ND 42 ND 12 352-93-2 Diethyl Sulfide ND 42 ND 12 109-79-5 n-Butyl Mercaptan ND 42 ND 12 624-92-0 Dimethyl Disulfide ND 22 ND 5.8 616-44-4 3-Methylthiophene ND 46 ND 12 110-01-0 Tetrahydrothiophene ND 41 ND 12 638-02-8 2,5-Dimethylthiophene ND 53 ND 12 872-55-9 2-Ethylthiophene ND 53 ND 12 110-81-6 Diethyl Disulfide ND 29 ND 5.8


13 of 17

20SULFUR.XLS - Page No.:P1304105R_ASTM5504_1309200846_RD.xls - MBlank

ALS ENVIRONMENTAL


Client: AECOMClient Sample ID: Method Blank ALS Project ID: P1304105Client Project ID: RDCO Odor Study ALS Sample ID: P130917-MB

Test Code: ASTM D 5504-08 Date Collected: NAInstrument ID: Agilent 6890A/GC13/SCD Time Collected: NAAnalyst: Mike Conejo Date Received: NASample Type: 6.0 L Silonite Canister Date Analyzed: 9/17/13Test Notes: Time Analyzed: 08:02 Volume(s) Analyzed: 1.0 ml(s)


7783-06-4 Hydrogen Sulfide ND 7.0 ND 5.0 463-58-1 Carbonyl Sulfide ND 12 ND 5.0 74-93-1 Methyl Mercaptan ND 9.8 ND 5.0 75-08-1 Ethyl Mercaptan ND 13 ND 5.0 75-18-3 Dimethyl Sulfide ND 13 ND 5.0 75-15-0 Carbon Disulfide ND 7.8 ND 2.5 75-33-2 Isopropyl Mercaptan ND 16 ND 5.0 75-66-1 tert-Butyl Mercaptan ND 18 ND 5.0 107-03-9 n-Propyl Mercaptan ND 16 ND 5.0 624-89-5 Ethyl Methyl Sulfide ND 16 ND 5.0 110-02-1 Thiophene ND 17 ND 5.0 513-44-0 Isobutyl Mercaptan ND 18 ND 5.0 352-93-2 Diethyl Sulfide ND 18 ND 5.0 109-79-5 n-Butyl Mercaptan ND 18 ND 5.0 624-92-0 Dimethyl Disulfide ND 9.6 ND 2.5 616-44-4 3-Methylthiophene ND 20 ND 5.0 110-01-0 Tetrahydrothiophene ND 18 ND 5.0 638-02-8 2,5-Dimethylthiophene ND 23 ND 5.0 872-55-9 2-Ethylthiophene ND 23 ND 5.0 110-81-6 Diethyl Disulfide ND 12 ND 2.5


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20SULFUR.XLS - Page No.:P1304105R_ASTM5504_1309200846_RD.xls - MBlank (2)

ALS ENVIRONMENTAL







15 of 17

20SULFUR.XLS - Page No.:P1304105R_ASTM5504_1309200846_RD.xls - LCS

ALS ENVIRONMENTAL

LABORATORY CONTROL SAMPLE SUMMARYPage 1 of 1

Client: AECOMClient Sample ID: Lab Control Sample ALS Project ID: P1304105Client Project ID: RDCO Odor Study ALS Sample ID: P130917-LCS

Test Code: ASTM D 5504-08 Date Collected: NAInstrument ID: Agilent 6890A/GC13/SCD Date Received: NAAnalyst: Mike Conejo Date Analyzed: 9/17/13Sample Type: 6.0 L Silonite Canister Volume(s) Analyzed: NA ml(s)Test Notes:

ALS

CAS # Compound Spike Amount Result % Recovery Acceptance DatappbV ppbV Limits Qualifier

7783-06-4 Hydrogen Sulfide 2,050 2,320 113 63-140 463-58-1 Carbonyl Sulfide 2,020 2,280 113 63-138 74-93-1 Methyl Mercaptan 1,890 2,440 129 63-144

16 of 17

20SULFUR.XLS - Page No.:P1304105R_ASTM5504_1309200846_RD.xls - LCS (2)

ALS ENVIRONMENTAL




ALS



17 of 17


LABORATORY REPORT October 9, 2013 Stephen Horsman AECOM 3275 Lakeshore Road Suite 201 Kelowna, BC V1W 3S9 Dear Stephen: Enclosed are the results of the samples submitted to our laboratory on September 19, 2013. For your reference, these analyses have been assigned our service request number P1304173. Please note that this report was revised to include a chain of custody received on October 4, 2013, as well as edit the sample ID names, and sampling date/times. No data was altered in this revision. All analyses were performed according to our laboratory’s NELAP and DoD-ELAP-approved quality assurance program. The test results meet requirements of the current NELAP and DoD-ELAP standards, where applicable, and except as noted in the laboratory case narrative provided. For a specific list of NELAP and DoD-ELAP-accredited analytes, refer to the certifications section at www.alsglobal.com. Results are intended to be considered in their entirety and apply only to the samples analyzed and reported herein. If you have any questions, please call me at (805) 526-7161. Respectfully submitted, ALS | Environmental Samantha Henningsen Project Manager




samantha.henningsen

Samantha


Client: AECOM Service Request No: P1304173 _______________________________________________________________________________

CASE NARRATIVE

The samples were received intact under chain of custody on September 19, 2013 and were stored in accordance with the analytical method requirements. Please refer to the sample acceptance check form for additional information. The results reported herein are applicable only to the condition of the samples at the time of sample receipt. Sulfur Analysis The samples were analyzed for twenty sulfur compounds per ASTM D 5504-08 using a gas chromatograph equipped with a sulfur chemiluminescence detector (SCD). All compounds with the exception of hydrogen sulfide and carbonyl sulfide are quantitated against the initial calibration curve for methyl mercaptan. This method is not included on the laboratory’s NELAP, DoD-ELAP, or AIHA-LAP scope of accreditation. ______________________________________________________________________________________ The results of analyses are given in the attached laboratory report. All results are intended to be considered in their entirety, and ALS Environmental (ALS) is not responsible for utilization of less than the complete report. Use of ALS Environmental (ALS)’s Name. Client shall not use ALS’s name or trademark in any marketing or reporting materials, press releases or in any other manner (“Materials”) whatsoever and shall not attribute to ALS any test result, tolerance or specification derived from ALS’s data (“Attribution”) without ALS’s prior written consent, which may be withheld by ALS for any reason in its sole discretion. To request ALS’s consent, Client shall provide copies of the proposed Materials or Attribution and describe in writing Client’s proposed use of such Materials or Attribution. If ALS has not provided written approval of the Materials or Attribution within ten (10) days of receipt from Client, Client’s request to use ALS’s name or trademark in any Materials or Attribution shall be deemed denied. ALS may, in its discretion, reasonably charge Client for its time in reviewing Materials or Attribution requests. Client acknowledges and agrees that the unauthorized use of ALS’s name or trademark may cause ALS to incur irreparable harm for which the recovery of money damages will be inadequate. Accordingly, Client acknowledges and agrees that a violation shall justify preliminary injunctive relief. For questions contact the laboratory.




ALS Environmental – Simi Valley

Certifications, Accreditations, and Registrations

Agency Web Site Number

AIHA http://www.aihaaccreditedlabs.org 101661

Arizona DHS http://www.azdhs.gov/lab/license/env.htm AZ0694

DoD ELAP http://www.pjlabs.com/search-accredited-labs L11-203

Florida DOH (NELAP)

http://www.doh.state.fl.us/lab/EnvLabCert/WaterCert.htm E871020

Maine DHHS http://www.maine.gov/dhhs/mecdc/environmental-health/water/dwp-services/labcert/labcert.htm

2012039

Minnesota DOH (NELAP)

http://www.health.state.mn.us/accreditation 581572

New Jersey DEP (NELAP)

http://www.nj.gov/dep/oqa/ CA009

New York DOH (NELAP)

http://www.wadsworth.org/labcert/elap/elap.html 11221

Oregon PHD (NELAP)


CA200007

Pennsylvania DEP http://www.depweb.state.pa.us/labs 68-03307

(Registration) Texas CEQ (NELAP)

http://www.tceq.texas.gov/field/qa/env_lab_accreditation.html T104704413-

13-4 Utah DOH (NELAP)

http://www.health.utah.gov/lab/labimp/certification/index.html CA01627201

3-3

Washington DOE http://www.ecy.wa.gov/programs/eap/labs/lab-accreditation.html C946

Analyses were performed according to our laboratory’s NELAP and DoD-ELAP approved quality assurance program. A complete listing of specific NELAP and DoD-ELAP certified analytes can be found in the certifications section at www.alsglobal.com, or at the accreditation body’s website. Each of the certifications listed above have an explicit Scope of Accreditation that applies to specific matrices/methods/analytes; therefore, please contact the laboratory for information corresponding to a particular certification.



http://www.aihaaccreditedlabs.org/

http://www.azdhs.gov/lab/license/env.htm

http://www.pjlabs.com/search-accredited-labs

http://www.doh.state.fl.us/lab/EnvLabCert/WaterCert.htm



http://www.health.state.mn.us/accreditation

http://www.nj.gov/dep/oqa/

http://www.wadsworth.org/labcert/elap/elap.html



http://www.depweb.state.pa.us/labs

http://www.tceq.texas.gov/field/qa/env_lab_accreditation.html

http://www.health.utah.gov/lab/labimp/certification/index.html

http://www.ecy.wa.gov/programs/eap/labs/lab-accreditation.html


P1304173_Detail Summary_1309271235_RG.xls - DETAIL SUMMARY




CollectedTime

CollectedContainer

IDPi1

(psig)Pf1

(psig)

Sample #7 R2 The Cove P1304173-001 Air 9/16/2013 18:55 AS00380 -0.85 3.55 XSample #11 R2 The Cove P1304173-002 Air 9/18/2013 09:38 AS00332 -0.48 3.64 XSample#8 R3 P1304173-003 Air 9/16/2013 19:24 AS00447 -0.79 3.64 XSample #12 R3 P1304173-004 Air 9/18/2013 09:50 AS00167 -0.57 3.61 XSample#9 R4 P1304173-005 Air 9/16/2013 19:35 AS00262 -0.78 3.61 XSample #10 R4 P1304173-006 Air 9/19/2008 09:05 AS00129 -2.07 3.51 X

ALS ENVIRONMENTAL


AST

M D

5504

-08

- Sul

fur C

an

Air - Chain of Custody Record & Analytical Service Request Page _ 1 __ of _1 __ _

2655 Park Center Drive, Suite A

Simi Valley, California 93065

Phone(805)526-7161 Requested Turnaround Time in Business Days (Surcharges) please circle ALS Project No.

Fax(805)526-7270 1 Day (100%) 2 Day (75%) 3 Day (50%) 4 Day (35%) 5 Day (25%) 10 Day-Standard

ALS Contact: Company Name & Address (Reporting Information) Project Name

AECOM RDCO Odor Study Analysis Method Suite 201-3725 Lakeshore Road Project Number

Kelowna, British Columbia, V1W 3S9 Canada 60306094

Project Manager P.O.# I Billing Information

Stephen Horsman Comments Phone Fax e.g. Actual

250-762-3727 250-762-7789 Preservative or -Email Address for Result Reporting Sampler (Print & Sign) tt;,, ~

specific instructions

steohen.horsmant5laecom.com Chr,·$ r>7 I/fr Laboratory Date Time

Canister ID Flow Controller ID Canister Canister Client Sample ID (Bar code#- (Barcode #- Start Pressure End Pressure Sample

ID Number Collected Collected AC, SC, etc.) FC#) "Hg "Hg/psig Volume

Sample #7 R2 The Cove 9/16/2013 6:55 pm 14030

Sample#8 R3 9/16/2013 7:24 pm 14223

Sample#9 R4 9/16/2013 7:35 pm 13099

Sample #10 R4 9/18/2013 9:05 am 5034

Sample #11 R2 The Cove 9/18/2013 9:38 am 13738

Sample #12 R3 9/18/2013 9:50 am 11537

Report Tier Levels - please select

Tier I - Results (Default if not specified) __ Tier Ill (Results+ QC & Calibration Summaries) __ EDD required Yes I No Project Requirements Tier II (Results + QC Summaries) -- Tier IV (Data Validation Package) 10% Surcharge __ Type: Units: (MRLs, QAPP)

Relinquished by: (Signature) Date: Time: Received by: (Signature) Date: Time:

Relinquished by: (Signature) Date: Time: Received by: (Signature) Date: Time: Cooler I Blank Temperature __ •c

10/9/2013 2:24 PMP1304173_AECOM_.xls - Page 1 of 1

ALS EnvironmentalSample Acceptance Check Form

Client: AECOM Work order: P1304173Project:Sample(s) received on: 9/19/2013 Date opened: 9/19/2013 by: MZAMORA

Note: This form is used for all samples received by ALS. The use of this form for custody seals is strictly meant to indicate presence/absence and not as an indication of

compliance or nonconformity. Thermal preservation and pH will only be evaluated either at the request of the client and/or as required by the method/SOP.Yes No N/A

1 Were sample containers properly marked with client sample ID? 2 Container(s) supplied by ALS? 3 Did sample containers arrive in good condition? 4 Were chain-of-custody papers used and filled out? 5 Did sample container labels and/or tags agree with custody papers? 6 Was sample volume received adequate for analysis? 7 Are samples within specified holding times? 8 Was proper temperature (thermal preservation) of cooler at receipt adhered to?

9 Was a trip blank received?

10 Were custody seals on outside of cooler/Box? Location of seal(s)? Sealing Lid?

Were signature and date included? Were seals intact? Were custody seals on outside of sample container?

Location of seal(s)? Sealing Lid? Were signature and date included? Were seals intact?

11 Is there a client indication that the submitted samples are pH preserved? Were VOA vials checked for presence/absence of air bubbles?

12 Tubes: Are the tubes capped and intact?

Do they contain moisture? 13 Badges: Are the badges properly capped and intact?

Are dual bed badges separated and individually capped and intact?

Lab Sample ID Container Required Received Adjusted VOA HeadspaceDescription pH * pH pH (Presence/Absence) Comments

6.0 L Silonite Can6.0 L Silonite Can6.0 L Silonite Can6.0 L Silonite Can6.0 L Silonite Can6.0 L Silonite Can

Missing chain of custody form

RSK - MEEPP, HCL (pH<2); RSK - CO2, (pH 5-8); Sulfur (pH>4)

P1304173-006.01

Explain any discrepancies: (include lab sample ID numbers):

Do containers have appropriate preservation, according to method/SOP or Client specified information?

Does the client/method/SOP require that the analyst check the sample pH and if necessary alter it?

Receipt / Preservation

P1304173-001.01P1304173-002.01P1304173-003.01P1304173-004.01P1304173-005.01

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ALS ENVIRONMENTAL


Client: AECOMClient Sample ID: Sample #7 R2 The Cove ALS Project ID: P1304173Client Project ID: RDCO Odor Study ALS Sample ID: P1304173-001





7783-06-4 Hydrogen Sulfide ND 9.2 ND 6.6 463-58-1 Carbonyl Sulfide ND 16 ND 6.6 74-93-1 Methyl Mercaptan ND 13 ND 6.6 75-08-1 Ethyl Mercaptan ND 17 ND 6.6 75-18-3 Dimethyl Sulfide ND 17 ND 6.6 75-15-0 Carbon Disulfide ND 10 ND 3.3 75-33-2 Isopropyl Mercaptan ND 21 ND 6.6 75-66-1 tert-Butyl Mercaptan ND 24 ND 6.6 107-03-9 n-Propyl Mercaptan ND 21 ND 6.6 624-89-5 Ethyl Methyl Sulfide ND 21 ND 6.6 110-02-1 Thiophene ND 23 ND 6.6 513-44-0 Isobutyl Mercaptan ND 24 ND 6.6 352-93-2 Diethyl Sulfide ND 24 ND 6.6 109-79-5 n-Butyl Mercaptan ND 24 ND 6.6 624-92-0 Dimethyl Disulfide ND 13 ND 3.3 616-44-4 3-Methylthiophene ND 26 ND 6.6 110-01-0 Tetrahydrothiophene ND 24 ND 6.6 638-02-8 2,5-Dimethylthiophene ND 30 ND 6.6 872-55-9 2-Ethylthiophene ND 30 ND 6.6 110-81-6 Diethyl Disulfide ND 16 ND 3.3


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Client: AECOMClient Sample ID: Sample #11 R2 The Cove ALS Project ID: P1304173Client Project ID: RDCO Odor Study ALS Sample ID: P1304173-002








ALS ENVIRONMENTAL


Client: AECOMClient Sample ID: Sample#8 R3 ALS Project ID: P1304173Client Project ID: RDCO Odor Study ALS Sample ID: P1304173-003








ALS ENVIRONMENTAL


Client: AECOMClient Sample ID: Sample #12 R3 ALS Project ID: P1304173Client Project ID: RDCO Odor Study ALS Sample ID: P1304173-004








ALS ENVIRONMENTAL


Client: AECOMClient Sample ID: Sample#9 R4 ALS Project ID: P1304173Client Project ID: RDCO Odor Study ALS Sample ID: P1304173-005








ALS ENVIRONMENTAL


Client: AECOMClient Sample ID: Sample #10 R4 ALS Project ID: P1304173Client Project ID: RDCO Odor Study ALS Sample ID: P1304173-006





7783-06-4 Hydrogen Sulfide ND 10 ND 7.2 463-58-1 Carbonyl Sulfide ND 18 ND 7.2 74-93-1 Methyl Mercaptan ND 14 ND 7.2 75-08-1 Ethyl Mercaptan ND 18 ND 7.2 75-18-3 Dimethyl Sulfide ND 18 ND 7.2 75-15-0 Carbon Disulfide ND 11 ND 3.6 75-33-2 Isopropyl Mercaptan ND 22 ND 7.2 75-66-1 tert-Butyl Mercaptan ND 27 ND 7.2 107-03-9 n-Propyl Mercaptan ND 22 ND 7.2 624-89-5 Ethyl Methyl Sulfide ND 22 ND 7.2 110-02-1 Thiophene ND 25 ND 7.2 513-44-0 Isobutyl Mercaptan ND 27 ND 7.2 352-93-2 Diethyl Sulfide ND 27 ND 7.2 109-79-5 n-Butyl Mercaptan ND 27 ND 7.2 624-92-0 Dimethyl Disulfide ND 14 ND 3.6 616-44-4 3-Methylthiophene ND 29 ND 7.2 110-01-0 Tetrahydrothiophene ND 26 ND 7.2 638-02-8 2,5-Dimethylthiophene ND 33 ND 7.2 872-55-9 2-Ethylthiophene ND 33 ND 7.2 110-81-6 Diethyl Disulfide ND 18 ND 3.6


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Appendix B:

Sludge Stabilization Comparative Analysis Table

Process Process Conditions (OMRR Requirement)

Process Class A/B

Pathogen Reduction Effectiveness

Vector Reduction Effectiveness

Odour Reduction

Advantages Disadvantages

Aerobic Digestion

Thermophilic

Temp > 55 C for t>30 min t = 50,070,000/10^(0.01400Temp)

-Reduces VS up to 70% and bacterial activity by 90% and viral activity by 50%. -lower residence times required

Produces ammonia Difficult to dewater NO3Agitation Required

A Effective Pathogen Reduction Effective Vector Attraction Reduction

Reduces odour of biosolids -potential generation of ammonia depending on process conditions

Conventional

t = 40 days at 20C or 60 days at 15 C

Reduces VS by 40% to 50% and and bacterial activity by 90% and viral activity by 50%. Low cost Simple operation

Requires space B Effective Pathogen Reduction Effective Vector Attraction Reduction

Reduces odour of biosolids -potential generation of ammonia depending on process conditions

Anaerobic Digestion

Thermophilic

Temp > 50C for t>10 days

-Reduces VS by 35% to 60 andbacterial and viral pathogens by 90% or more. -Complex operation

- Produces CO2, CH4, NH3 -If electricity recovery not suitable, permitting for flare is required - Addition odour control required

A Effective Pathogen Reduction Effective Vector Attraction Reduction

Reduces odour of biosolids Odorous process – generation of sulphides and ammonia

Conventional

t = 15 days at 35 - 55C or 60 days at 20 C

- Denser biosolids after dewatering

- Biogas Recovery if feasible

- Produces CO2, CH4, NH3 -If electricity recovery not suitable, permitting for flare is required - Addition odour control required

Effective Pathogen Reduction Effective Vector Attraction Reduction

Reduces odour of biosolids Odorous process – generation of sulphides and ammonia

Heat Treatment (% Solids > 7)

Temp>50 C ; t> 20 min t = 131,700,000/10^(0.01400Temp)

Produced marketable product when combined with the right processes

Most effective with digested and dewater solids

A Effective Pathogen Reduction Requires additional processing (pH adjustment, heat drying, injection in soil)

No odour reduction if solids are not dewatered

Heat Treatment by Gases or Liquid (% Solids > 7)

Temp>50 C; t> 15 sec t = 131,700,000/10^(0.01400Temp)





Heat Treatment (% Solids <7)

15 sec <t >30 min; t> 15 sec t = 131,700,000/10^(0.01400Temp)





Heat Treatment (% Solids <7

Temp>50 C; t> 30 min t = 50,070,000/10^(0.01400Temp)





Air-Drying Sand beds or basins required t> 3 months; Temp > 0C

- Requires space and time - Climate Dependent - Odour concerns

Effective Pathogen Reduction Requires partial digestion as first step


Alkaline Stabilization

pH < 12 for 72hrs with Temp>52C for 12hr; Biosolids air-dried to >50% total solids

A Effective Pathogen Reduction Does not reduce food source – temporarily stops biological activity

- Amine and Ammonia Release -Amine Release dependent on dewatering chemical used

Lime stabilization (temporary)

pH = 12 for t= 2hrs - Can be combined with the dewatered sewage sludge (entire mass must come into contact) -Lime stabilized material creates odour problem is pH<10.5

B Satisfactory Pathogen Reduction Addition of Alkali is required Lime stabilized material creates odour problem is pH<10.5

pH = 12 for t= 24hrs -odors can be better controlled B Satisfactory Pathogen Reduction Does not reduce food source – temporarily stops biological activity

Lime stabilized material creates odour problem is pH<10.5

Appendix C:

Aerobic Digestion Installation Example

26 FEBRUARY 2013

SLUDGETREATMENT

AN EXERCISE IN AEROBIC DIGESTION

Pennsylvania

municipal i ty improves

sludge digest ion &

reduces energy use

The Frackville Area Municipal Authority (FAMA) Wastewater Treatment Facility (WWTF) in Frackville, Pa., currently oper-

ates an Ovivo Airbeam cover aerobic digestion system that was commissioned in October 2010.

FAMA was seeking to upgrade and improve its aerobic digestion system, so it contacted Entech Eng. to design a new system that would reduce the amount of solids that needed to be disposed for land application.

Aerobic Digestion System DesignPreviously, aerobic digestion at the FAMA

WWTF was conducted through a f loor-mounted coarse-bubble diffuser system in uncovered aer-obic digester tanks. Entech proposed to retrofit the two existing aerobic digestion tanks with an Ovivo Airbeam cover aerobic digestion sys-tem. This would minimize operating and capital costs and provide maximum mixing and aera-tion efficiency of waste-activated sludge while using minimum energy requirements, reducing odors and providing optimum temperature con-trol to improve digestion. Covering the aerobic digester tanks provided faster kinetic reactions in the system, resulting in shorter solids reten-tion time in the existing tanks to obtain Class B stabilized sludge, which eliminated the need to construct new tanks.

Each aerobic digester tank was designed with an Airbeam cover integrating Ovivo’s Mansel Smith diffusers and shear tubes. The shear tubes allow the diffusers to be submerged sev-eral feet above the bottom of the tank f loor, reducing the blower discharge pressure, result-ing in lowering energy requirements of the aero-bic digestion operations.

Reduced EnergyIn comparison with the prior f loor-mounted

diffuser system, the shear tube design is capable of lowering the discharge pressure of the blower system by nearly 1.5 psig, resulting in a reduction of more than a 15% in annual energy usage at the FAMA WWTF since its incorporation of the new aerobic digestion system. The reduced energy usage from this system saves FAMA $18,000 annually in energy costs.

Pennsylvania Power & Light (PPL) Electric Utilities currently offers financial incentives

under its E-power Program to facilitate the implementation of cost-effective, energy-efficient equipment for commercial, industrial, govern-mental, institutional and nonprofit customers. The E-power incentive program pays on a per-unit-of-energy-saved (in kilowatt hours) basis. Due to the reduction in energy usage provided by its new aerobic digestion system, FAMA applied for this incentive. It was granted a $27,503 energy efficiency rebate from PPL in February 2012.

Reduced Sludge Disposal Enhanced temperature control provided by the

new aerobic digestion system greatly improved digestion performance at the FAMA WWTF. After the solids are digested by the aerobic digestion system, they are dewatered with a belt press; then the Class B solids are land applied. Prior to incor-poration of the new system, 250 acres were used to land apply the solids. After installation, 172 acres are used, resulting in a reduction of more than 30%.

Prior to the new aerobic digestion system, FAMA disposed of 1,036 wet tons of solids in 2009, costing $26,000. After installation, it disposed of 444 wet tons of solids in 2011, costing $11,000. By substantially improving sludge digestion, the new system provides an almost two-and-a-half times reduction in sludge disposal, generating savings of $15,000 annually in disposal costs.

Improved Digestion PerformanceThe Airbeam Cover aerobic digestion system

at the FAMA WWTF has improved digestion performance and substantially reduced energy usage without having the facility having to build additional tank volume. The improvements have resulted in a 57%-plus reduction in solids disposed and a 15% reduction in annual energy costs. FAMA is able to save a total of $33,000 annually through reduced energy and disposal costs alone.

A R T I C L E S U M M A R Y

Challenge: The Frackville Area Municipal Authority sought to upgrade and improve

its aerobic digestion system.

Solution: The engineering firm proposed retrofitting the two existing aerobic digestion tanks with a new aerobic

digestion system to minimize operating and capital costs and provide maximum

mixing and aeration efficiency of waste-activated sludge.

Conclusion: The new system has improved digestion performance and substantially

reduced energy usage without creating a need for additional tank volume.

Appendix D:

Field Notes

Appendix E:

Wind Conditions

Date Time Temperature

(°C)

Relative Humidity

(%)

Wind Direction Wind Speed

(km/h)

Pressure (kPa)

September 9, 2013 9:00 17.6 81 North-North West 5 96.65


September 9, 2013 11:00 21.1 61 Calm 0 96.59

September 9, 2013 12:00 22.8 58 North-East 4 96.55



September 9, 2013 15:00 25.9 48 North 11 96.37



September 9, 2013 18:00 25.3 53 North East 11 96.3

September 9, 2013 19:00 24.4 51 M 4 96.29

September 9, 2013 20:00 19.9 76 North East 5 96.35

September 10, 2013 9:00 17.5 77 North 5 96.88



September 10, 2013 12:00 22.3 56 North 11 96.85


September 10, 2013 14:00 25.3 42 North 11 96.74

September 10, 2013 15:00 26 39 North 11 96.69

September 10, 2013 16:00 27 31 North 13 96.63

September 10, 2013 17:00 27.1 33 North 9 96.61

September 10, 2013 18:00 26.4 37 North-North-East 5 96.61


September 10, 2013 20:00 18.2 73 M 4 96.67

September 11, 2013 9:00 16.8 65 North 8 97.11

September 11, 2013 10:00 19 58 North 8 97.1




September 11, 2013 14:00 25.9 41 North 9 96.9


September 11, 2013 16:00 27.2 35 North 8 96.76

September 11, 2013 17:00 27.8 36 North 5 96.71

September 11, 2013 18:00 27.3 41 Souht-South-East 5 96.67

September 11, 2013 19:00 24.9 50 West-South-West 5 96.66


September 12, 2013 9:00 18.3 68 East-North-East 4 96.82

September 12, 2013 10:00 20.8 60 South-East 4 96.77

September 12, 2013 11:00 22.4 57 Calm 0 96.7

September 12, 2013 12:00 24.8 51 South 4 96.59


September 12, 2013 14:00 27.4 43 South-South-East 4 96.44

September 12, 2013 15:00 29.1 36 North 5 96.34

September 12, 2013 16:00 30.4 34 South-West 5 96.24

September 12, 2013 17:00 29.7 37 North 13 96.17

September 12, 2013 18:00 27.9 45 North-North-West 9 96.13


September 12, 2013 20:00 20.6 70 Calm 0 96.13

Wind Conditions on Monitoring and Sampling Days

Date Time Temperature

(°C)

Relative Humidity

(%)

Wind Direction Wind Speed

(km/h)

Pressure (kPa)

Wind Conditions on Monitoring and Sampling Days

September 13, 2013 9:00 19.1 71 North 8 96.3

September 13, 2013 10:00 21.3 58 North 5 96.3

September 13, 2013 11:00 23.6 54 North 11 96.24


September 13, 2013 13:00 26.8 43 North 9 96.1

September 13, 2013 14:00 28.1 41 North 9 96.03

September 13, 2013 15:00 29.1 35 North 5 95.97

September 13, 2013 16:00 29.9 33 North 8 95.9

September 13, 2013 17:00 30.7 31 Calm 0 95.86

September 13, 2013 18:00 30 37 Calm 0 95.82




September 16, 2013 10:00 17 78 South 5 95.87

September 16, 2013 11:00 18.7 71 South-South-Ease 11 95.87


September 16, 2013 13:00 22 55 South 13 95.85


September 16, 2013 15:00 22.5 47 South 21 95.76

September 16, 2013 16:00 23.2 43 South 17 95.72

September 16, 2013 17:00 22.5 45 South 17 95.7

September 16, 2013 18:00 22.9 41 South-South-West 18 95.7

September 16, 2013 19:00 21.8 40 West-North-West 18 95.75

September 16, 2013 20:00 20.6 43 West-North-West 11 95.86

September 18, 2013 9:00 14.3 71 M 4 96.19


September 18, 2013 11:00 18.3 47 South 9 96.23


September 18, 2013 13:00 20.2 44 South 13 96.22


September 18, 2013 15:00 19.8 38 South-West 13 96.24

September 18, 2013 16:00 19.5 35 North-North-West 8 96.27

September 18, 2013 17:00 18.3 46 South-South-West 11 96.34

September 18, 2013 18:00 17.2 59 South 11 96.39

September 18, 2013 19:00 15.9 59 M 4 96.42

September 18, 2013 20:00 14 67 South-East 9 96.52

page 1 of 22 october 21st, 2013 peter rotheisler manager of

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