Attachment 8-3 FtlewisOperPlan0207.pdf

Fort Lewis Compost Facility Revised February 26, 2007 1

FORT LEWIS SEQUALITCHEW CREEK ECO PARK &

EARTHWORKS COMPOSTING FACILITY

COMPOSTING FACILITY PLAN OF OPERATION

WAC173-350-220(4)(e)

Table of Contents

General Page Introduction 2 Facility Description 2 Receiving and Processing of Yard Debris Materials 4 Environmental Protection 6

Solid Waste Handling Standards Operations Plan

WAC 173 350-220(4)(e)(i) List of Feedstocks and Description of Source 7 WAC 173 350-220(4)(e)(ii)(A) Acceptance Criteria 7 WAC 173 350-220(4)(e)(ii)(B) Procedure Ensuring Described Waste will be Accepted 8 WAC 173 350-220(4)(e)(ii)(C) Procedure for Handling Unacceptable Wastes 8 WAC 173 350-220(4)(e)(ii)(D) Mass Balance Calculations 8 WAC 173 350-220(4)(e)(ii)(E) Material Flow Plan 9 WAC 173 350-220(4)(e)(ii)(F) Equipment Description 13 WAC 173 350-220(4)(e)(ii)(G) Process Monitoring Plan 13 WAC 173 350-220(4)(e)(ii)(H) Pathogen Reduction Plan 20 WAC 173 350-220(4)(e)(ii)(I) Sampling and Analysis Plan 20 WAC 173 350-220(4)(e)(ii)(J) Nuisance Odor Management Plan 32 WAC 173 350-220(4)(e)(ii)(K) Leachate Management Plan 36 WAC 173 350-220(4)(e)(ii)(L) Stormwater Management Plan 37 WAC 173 350-220(4)(e)(iii) Equipment and Structure Inspection 38 WAC 173 350-220(4)(e)(iv) Neighbor Relations Plan 38 WAC 173 350-220(4)(e)(v) Safety, Fire and Emergency 39 WAC 173 350-220(4)(e)(vi) Forms for Recordkeeping 43 WAC 173-350-220(3) Engineering Reports, Plans and Specifications 44 WAC 173-350-220(6) Closure Plan 46

DEQ000878J Attch 8-3

Fort Lewis Compost Facility Revised February 26, 2007 2

Appendices

A - Weekly Site Inspection Form 47 B - Compost Pile Monitoring Form 49 C - Odor Response Information Sheet 53 D - Engineering Reports, Plans, and Specifications 55

General

Introduction

Overview

Fort Lewis proposes to operate a biosolids/food waste/yard waste compost facility located in Pierce County, Washington. Site operations will be conducted in accordance with the provisions of this Plan of Operation.

Fort Lewis’s mission is to preserve and enhance the environment by providing cost effective composting of biosolids, food waste, horse manure, land clearing debris, and yard debris from Fort Lewis waste water treatment plant, landscaping activities, food services, and horse facilities. Food wastes from Fort Lewis dining halls will be incorporated in future compost operations Fort Lewis serves to create a service beneficial to all people of Fort Lewis and surrounding areas by providing alternatives to landfilling, A quality soil amendment and landscaping products will be produced.

Purpose and Objectives

The purpose of this document is to describe the acceptable methods of operation, to protect the environment and human health and to assure a safe work place for site operations personnel. This document will also describe how information and records will be collected and maintained in accordance with state and local regulations.

The objective of this document is to provide operations and safety guidelines to all site personnel, and protect the environment and human health. This plan of operation is a living document, which requires routine review and update.

Facility Description

Location

The Fort Lewis compost site is in Pierce County. The site is owned by Fort Lewis.

The composting facility will be operated by Fort Lewis.

Fort Lewis Compost Facility Revised February 26, 2007 3

Sequalitchew Creek Eco Park and Earthworks Composting Facility

Figure 1

Access

Site access is from Steilacoom-Dupont Road. The site is designated as Eco Park/

Landfill 5 on the above map, Figure 1.

Site Contact

Ken Smith – Branch Chief Fort Lewis Public Works

IMNW-LEW-PW MS-17

Box 339500 Fort Lewis, WA 98433-9500

(253) 966-3275 ken.smith1@us.army.mil

Alternate Contact:

Ron Norton Fort Lewis Public Works

IMNW-LEW-PW MS-17

Box 339500 Fort Lewis, WA 98433-9500

(253) 966-6452 ron.norton1@us.army.mil

Fort Lewis Compost Facility Revised February 26, 2007 4

Hours of Operation

Hours of operation for receiving and processing materials will typically be 7:30 am to 4:00 pm, Monday through Friday

Site Description

Fort Lewis Sequalitchew Creek Eco Park & Earthworks Composting Facility is located at Fort Lewis Landfill No. 5 and reuses a closed MSW transfer station as the composting facility.

The existing maximum volume for the active composting area is 1200 -1600 cubic yards. A separate area (6,750 ft2) will be used for receiving and mixing feed stocks.

Curing will take place in an either an area adjacent to the mixing area or in an enclosed part of the facility that is approximately 8,100 ft2 in size. All active composting and feedstock mixing will occur under a roof.

Utilities

Please refer to Appendix D – Site Plan for the locations of electric, water, and sewer utilities. A fire protection water hydrant is located to the immediate north of the scale house building (7600). Communications on site will be by cell phones and land lines located in the scale house.

Receiving and Processing Yard Debris Materials

Inspection of Loads Received

Only materials from Fort Lewis, Mc Chord AFB, Camp Murray and the VA Hospital American Lake will be accepted for composting.

The following is a list of materials that will be accepted at the composting facility.

Information about what is accepted will be provided by either a written list or verbally to all persons/debris haulers from the above sources providing feed stocks for composting purposes.

• Grass clippings

• Leaves

• Chipped land clearing and storm debris

• Landscaping waste (ornamental plant pruning debris)

• Horse manure

• Biosolids

• Waste paper (shredded or pulverized)

• Food waste

All incoming loads will be directed to a specified dumping area. As the truck bed gates are opened, and as the load is being dumped, the yard debris will be inspected by on-site personnel.

Fort Lewis Compost Facility Revised February 26, 2007 5

In the event that direct inspection is not possible, the daily records will be compared to loads received. A hauler responsible for delivering an unacceptable load will be notified to return to the site to retrieve the unacceptable materials. These haulers will bear the cost of reloading these materials, and they will receive a warning not to deliver unacceptable materials in the future. Repeat offenses will not be tolerated.

Materials Handling / Stockpiling

Yard Debris

The yard debris will be dumped into the receiving area. If the potential for odor generation from yard debris exists (decomposed anaerobic conditions) the incoming yard debris will be covered with a layer of mulch to contain odors until such time that the materials are mixed and placed into aerated compost piles.

Coarse, woody materials will be processed as needed to supply sufficient quantities of bulking materials. Processing will be accomplished by using a portable tub grinder or other suitable reduction equipment. The frequency of processing will be based on the volumes of materials received.

Following material reduction and mixing, the coarse and woody yard debris will be mixed with biosolids, horse manure or food waste as a source of nitrogen and placed on aeration piping in the bays. All composted materials will be processed using the aerated static pile method. The feedstock materials will be combined in accordance with a mass balance for the materials, striving to attain an initial moisture content of approximately 60% and a Carbon to Nitrogen (C:N) ratio of 30:1.

The aerated static pile method of composting employs the use of perforated pipes within a wood chip plenum located beneath the yard debris windrow. The perforated pipes are connected to an electric blower(s) to force air into the compost pile, thereby maintaining aerobic conditions within the windrow. The frequency and duration of blower operation is dependent upon several factors, some of which include the pile temperature, moisture content and activity of the compost materials.

In general, individual aerated static piles will measure approximately 50 feet long and 22 feet wide. The initial height of the pile will be on the order of 6 to10 feet, shrinking during the active composting phase to 5 to 8 feet.

At the completion of active composting, the materials will be moved as is or screened to a pile or short row configuration for curing. At a minimum curing will take place for 30 - 60 days. The curing process results in a stable compost product that has greater value as a soil admixture and as compost mulch. The screened course fraction (overs) will be used as compost mulch or will be further reduced and re-composted.

After curing the piles will be screened to ½ inch minus. The resulting product will then be moved to an outdoor product storage area.

Fort Lewis Compost Facility Revised February 26, 2007 6

All composting operations conducted at the Fort Lewis facility will comply with the state and local regulations, along with any conditions listed as part of the Tacoma/ Pierce County Health Department Solid Waste Handling Permit.

Residual Materials

All waste materials not suitable for composting will be disposed of at a permitted municipal solid waste handling facility. Non-yard debris materials, which cannot be processed, typically include metal debris, garden tools, rock, etc. These materials will be placed into a dumpster container, and when a full load has been gathered, it will be transported to a local permitted waste disposal facility.

Environmental Protection

Surface Water

Composting operations will be conducted on a reinforced concrete pad under a roof with a leachate collection system. Leachate generated will be transferred to the wastewater treatment system. Storm water will be directed away from the composting surface area and be allowed to infiltrate into the ground around the facility.

Ground Water

The yard debris will be processed and stored on a reinforced concrete pad under cover. No impact on ground water is anticipated.

Finished screened compost product will be stored in piles directly on the ground.

The stockpiles will be located adjacent to the composting facility to minimize handling and to facilitate loading trucks for off-site product distribution or storage.

Air

Emissions to the air would generally be limited to diesel exhaust from on-site operating equipment and trucks. Dust resulting from vehicle traffic and periodic on-site yard debris chipping and screening will likely occur during periods of prolonged dry weather. There is no smoke associated with the proposed project.

Generally, stock piled compost will have a moisture content of 45 percent or greater, even during the driest summer months. This moisture content is sufficient to prevent the finer particles from becoming air borne and creating dust. In the event that screening operations do result in fugitive dust, the compost will be lightly sprayed with water to prevent the creation of dust.

Dust emissions on the roads will be controlled by spraying with water during periods of dry weather and/or the application of dust retardant sprays. Dust emissions resulting from yard debris processing will be controlled by spraying a mist of water through existing water nozzles on the processing equipment.

Fort Lewis Compost Facility Revised February 26, 2007 7

In general, composting operations can result in offensive odors when vegetative materials are not properly managed (i.e., when they are allowed to become anaerobic). Fort Lewis will utilize the aerated static pile method of composting to mitigate the potential of offensive odors. In the event of odor complaints, both the Tacoma/Pierce County Health Department (TPCHD) and PSCAA will be contacted to propose measures to mitigate the source and cause of the offensive odors.

Managing odors at a composting facility includes the following elements:

• Proper initial mix of compost materials;

• Positive or negative aeration of the compost pile to maintain aerobic conditions;

• Biofiltration of off-gases to digest odorous compounds; and

• Good housekeeping practices to minimize sources of odor.

An odor management plan has been prepared for this facility and is discussed in Section WAC 173 350-220(4)(e)(ii)(J).

WAC 173 350-220(4)(e)(i) List of Feedstocks and Description of Source

Types of Materials Processed

Fort Lewis will process biosolids/ biogrease, food waste, grass, prunings, leaves, horse manure, food waste, chipped wood debris and shredded or pulverized paper.

Any load that contains greater than 5 percent solid waste that is not listed as acceptable material ,will not be allowed , (i.e., garbage, garden tools, contaminated soil) Other types of organic wastes not included in the above list may be accepted with prior TPCHD approval.

Quantities of Yard Debris Received

Fort Lewis anticipates approximately 1300 - 1500 tons of regulated feedstock annually. Percentages will be determined by season, the regional needs, nutrient needs and bulking characteristics.

WAC 173 350-220(4)(e)(ii)(A) Acceptance Criteria

Types of Materials not Acceptable

Materials, which are not acceptable, include the following list:

• Liquids of any type

• Dimensional lumber

• Painted and/or treated wood products

• Chemically contaminated soils

• Municipal Solid Waste,

• Sheetrock or paper/cardboard recycled from sheetrock.

• Building demolition debris

• Insulation

• Roofing materials including wood shingles

Fort Lewis Compost Facility Revised February 26, 2007 8

WAC 173 350-220(4)(e)(ii)(B) Procedure for Ensuring Described Waste will be Accepted

A specific written list of materials or verbal instruction by compost facility staff of what will and will not be accepted at the compost facility will be provided to all waste haulers and their respective truck drivers as well as posted on signs at the facility.

WAC 173 350-220(4)(e)(ii)(C) Procedure for Handling Unacceptable Wastes

All incoming loads will be directed to a specified unloading area (asphalted mixing area). As the truck bed gates are opened, and as the load is being dumped, on-site personnel will inspect the waste load. In the event that the site operator is temporarily occupied with other activities and direct inspection is not possible, the daily records will be compared to loads received and any hauler responsible for delivering unacceptable loads will be notified to return to the site to retrieve the unacceptable materials.

These haulers will bear the cost of reloading these materials, and they will receive a warning not to deliver unacceptable materials in the future. Repeat offenses will not be tolerated, and Fort Lewis PW/ED reserves the right to ban these haulers from the site.

WAC 173 350-220(4)(e)(ii)(D) Mass Balance Calculations:

Materials Mass Balance

Mass balance estimates are used for planning purposes, and are not intended to be prescriptive. It must be understood that because conditions and material properties vary seasonally, the site operator must develop a talent for making adjustments to the mix composition and ratio of bulking agents in order to prepare an initial mix that can be effectively and efficiently composted.

During the spring and early summer months, the wet, nitrogen rich green waste will be blended with a higher proportion of ground woody residuals or screened overs.

As the season progresses, the ratio of bulking materials will be adjusted to allow more green waste to account for the changes in moisture and nitrogen content.

During the winter months, the bulking agent will be comprised almost entirely of ground wood residuals and screened overs.

The materials mass balance and monthly average quantities of feedstock materials are summarized in Table 1.

As shown in Table 1, the target-bulking ratio is 0.6 parts bulking agent to 1 part green waste. For this evaluation, based on average conditions, the initial moisture content will be approximately 65 percent, the carbon to nitrogen ratio will be on the order of 30:1, and the initial bulk density will be roughly 850 pounds per cubic yard.

Fort Lewis Compost Facility Revised February 26, 2007 9

Description Cubic Yards

Per Year

Bulk Density

Lbs/Cubic yd

Wet Weight (Tons/ Yr.)

Input Yard Debris 555 900 250 Horse Manure 200 1000 100 Wood Waste (not regulated)

1975 800 790

Biosolids 364 1650 300 Food Waste 727 1650 600 Pulverized paper 24 1000 12 Total Estimated Regulated Quantity In-Put Mix / Year

1870 1350 1262

Total Estimated Quantity In- Put Mix / Year

3845 933 2052

Output 40 % reduction Total Estimated Quantity Output Product

900 1231

Table 1

The yard debris fraction of the mass balance will change significantly during the year. As would be expected, the majority of green waste will be available beginning in March / April (depending on the year) and continue through mid to late November.

Comparatively small quantities of yard debris are generated during the months December through February. Table 1 reflects assumptions for average feedstock quantities.

In addition, the composition and nutrient character of the green waste changes significantly as well. During the spring and early summer months, it is comprised primarily of wet, nitrogen rich lawn clippings and trimmings. As the summer and early fall seasons advance, the materials become progressively drier and more carbonaceous. By late fall the materials consist predominantly of leaves. The small amount of green waste available during the winter months consists primarily of tree and shrub pruning waste.

WAC 173 350-220(4)(e)(ii)(E) Material Flow Plan

Process Description

Process Material Flow Diagram

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The mass balance values provided in the proceeding sections are annual quantities.

While variations will likely occur on a daily and weekly basis, it is reasonable to assume that monthly averages are suitable for design purposes. A process material flow diagram, based on a mass balance of projected material, is provided as Figure

2. Each operations step depicted in the flow diagram is discussed in the following sections.

Receiving

A specific list of materials that will and will not be accepted at Fort Lewis will be provided via written or verbal instruction to all Fort Lewis activities, companies and their respective truck drivers as well as posted on signs at the facility.

CURING

30 to 60 days

COMPOST PRODUCT

CURING

0 TO 90 DAYS

ACTIVE COMPOSTING

21 TO 30 dAYS

SCREENING AND

DISTRIBUTION

Spring through Fall

Figure 2

Curing (45 - 60 Days)

Fort Lewis

Composting Process Flow Diagram

PREPARATION

Grinding Mixing Moisture Conditioning

FEEDSTOCKS

Yard debris Food waste Horse manure Biosolids Paper

BULKING

Chipped wood Mulch

Fort Lewis Compost Facility February 26, 2007

Mixing/Bulking Agents

Bulking agents are materials (i.e., organic and/or inorganic) that have sufficient size to provide structural support and maintain air spaces within the composting matrix.

Bulking agents form a three-dimensional matrix of solid particles capable of self-support by particle-to-particle contacts. Grass clippings, biosolids and other “wet” feedstocks can be viewed as supporting the voids between particles.

The bulking agents to be used for this process include: shredded wood waste, and compost screened overs (i.e., coarse fraction). In the case of shredded green waste, the available nutrients are a source of energy for the compost material and thereby provide a secondary benefit. The screened overs serve to inoculate the initial mix of compost materials with microorganisms and to provide structure and porosity in the pile. These materials will be preprocessed to a 2-4 inch size.

Pre- Processing and Batch Mixing

Size reduction of the yard debris materials will be accomplished with a front-end loader and a grinder. Incoming materials will be reduced to a 2-4 inch minus size and blended with bulking materials (shredded wood waste and agricultural residuals) as needed to provide an initial mix that has a carbon to nitrogen ratio (C:N) of approximately 30:1 and a moisture content of 60 to 65 percent.

The initial mixing will be accomplished to produce a homogeneous blend of materials (as the first step to mitigate potentially offensive odors). Mixing will be accomplished by using a front-end loader and grinder if necessary. If feedstock cannot be processed immediately upon delivery it will be covered with a 6 inch layer of wood waste bulking material to minimize odors.

As part of start-up operations, composite (i.e., representative) samples of the initial mix will be taken and tested. Suitable methods of sampling and testing are discussed in detail in the “Quality Assurance Plan” section of this Permit Application.

Test results will: 1) confirm that desired mix parameters are attained (i.e. moisture content, C:N ratio); and 2) provide baseline data to compare with lab results for the finished compost. Seasonal adjustments of the initial mix will be necessary, given that the character of the yard debris is expected to change from wet nitrogen rich materials during the spring, to dry carbon rich materials during the fall season. The flow of yard debris materials to the site during the winter months will generally consist of prunings, Christmas trees and other carbon rich wastes that will likely not require immediate processing to mitigate potentially offensive odors.

Active Composting

Extended Aerated Static Pile Composting / Odor Management

Fort Lewis will utilize the Aerated Static Pile (ASP) method of composting for feedstocks such as municipal green waste, agricultural waste. The ASP method uses perforated pipes installed beneath the compost pile, connected to electric blowers which can either force air into the compost pile (positive aeration) or draw air through the pile (negative aeration).

Positive aeration will be the primary mode of operation for the Fort Lewis ASP processing. For a detailed discussion on extended aerated static pile composting, refer to the “Controlled Aerobic Composting” section of this Permit Application. For a detailed discussion on Odor Management and biofilter design parameters, refer to the “Odor Management at Compost Facilities” section of this Permit Application.

As the compost pile is constructed, a 12-inch thick cover (i.e., minimum thickness) of finished compost or wood residuals will be placed over the newly mixed feedstock materials. The cover serves three main purposes, including:

1. Acting as an insulation blanket to ensure that all of the materials reach desired temperatures for pathogen reduction, weed seed destruction, and vector attraction reduction;

2. Serving as a biofilter to digest odor-causing compounds before being emitted to the open air, and;

3. Helping to maintain the desired moisture content within the pile.

By maintaining an oxygen level of at least 5 to 8 percent within the pile, aerobic conditions will be met, thereby mitigating offensive odors.

The piles will measure approximately 22 feet wide by up to 50 feet long. The initial height of the pile will be on the order of 6 to 10 feet; however, shrinkage will occur as a result of material consolidation and decomposition, reducing overall pile height to 5 to 8 feet by the end of the active phase of composting.

Active Composting

The active phase of composting (the period during which most of the process heat and potentially offensive odors are generated) lasts between 21 and 30 days and will take place in extended aerated static piles, as discussed previously. Regardless of feed stock, all organic materials composted at the Fort Lewis composting facility will meet the following Processes to Further Reduce Pathogens (PFRP) and Vector Attraction Reduction (VAR) regulatory requirements.

• During the active phase of composting PFRP and VAR will be met. PFRP is reached after temperatures within the pile have been maintained above 55ºC (131ºF) for a minimum of 72 hours.

• VAR is reached after pile temperatures are above 40ºC (104ºF) for a minimum of 14 days (including PFRP) and the average temperature must be higher than 45°C (113°F) during this time. The VAR requirements are applicable to biosolids composting only (WAC 173-308).

Curing

The subsequent curing phase of composting (the period during which the product becomes stable and marketable), lasts an additional 30 to 60 days. The curing phase may be accomplished either in the original compost pile, with adjusted airflow, or in a separate stockpile. If the finished product is to be screened, the screening process can take place either before or following product curing. The product curing area is shown on the site plans provided in Appendix D.

WAC 173 350-220(4)(e)(ii)(F) Equipment Description

Equipment used on site includes:

• A 120 foot by 90 foot existing covered concrete pad

• Caterpillar 940 Front End Loader

• John Deer Loader Tractor Model 54400

• John Deer Skid Loader Model 317

• Aerated Static Pile aeration equipment including

Electrical support equipment Timers – 4 Blowers 4 4 inch piping for distribution of air Butterfly valves for distribution of air

• Trommel Screen McCloskey 516 RE

• Water Spray Hoses

WAC 173 350-220(4)(e)(ii)(G) Process Monitoring Plan

Compost Monitoring and Control Parameters

Composting is a controlled biological process designed to rapidly convert waste organic material into a humus-like, rich material that is useful for a variety of purposes associated with landscaping and growing plants. The controlled aspect allows the process to be completed efficiently. Process control requires that appropriate monitoring be undertaken and process adjustments be performed based on parameter behavior. The extent of monitoring and control for composting varies widely depending on the complexity of the composting method used and the degree of process optimization desired. Since compost is a product that is utilized for plant growth and landscaping, the character of the final product is critical to successful marketing.

The compost monitoring and control parameters are discussed in the following sections.

Initial Mix Ratios and Characteristics

Mix ratio development and characteristics are critical to successful composting. Mix ratio refers to the ratio or portion of each feedstock in the initial mix. The initial mix impacts a number of processing parameters including: processing time, aeration requirements, odor generation, leachate production and final product quality. The following parameters are significant in the initial mix:

• Porosity

• Moisture Content

• Available Carbon Content

• Nutrient Content (i.e., C:N Ratio)

Porosity

Porosity is of primary importance for initial mixing. A mix with insufficient porosity will limit aeration. Porosity is provided in a mix by large particle size materials such s chipped brush and wood chips. The moisture content of the mix also influences porosity. If the moisture content is excessive, pore spaces are filled with water instead of air. In general, the porosity is considered optimal if the moisture content is less than 60 percent and the bulk density is less than approximately 900 pounds per cubic yard.

The optimum porosity / moisture is dependent on the moisture holding capacity of the initial mix. Experience working with the various feedstocks at a specific site will dictate what the optimum bulk density and moisture content of an initial mix should

be. The wet, dense and putrescent nature of semisolid organic wastes (e.g., biosolids with <12 percent solids) requires that the initial mix has sufficient porosity.

Moisture Content

Maintaining the moisture content of a compost pile within the optimum range is critical to successful composting. Sufficient water must be available for microbial activity. At the opposite extreme, excessive moisture content reduces porosity that promotes odor producing anaerobic conditions and slows the decomposition process. Excessive moisture also acts as a heat sink, reducing pile temperatures.

The optimum moisture content for composting is considered to range from 40 to 60 percent, although some feedstocks may successfully be composted with higher initial moisture contents.

Available Carbon Content

Heat is generated during the composting process as a result of the rapid decomposition of organic compounds that are readily available as a substrate for microbial growth. Substrates such as sugars, starches, fats and proteins are considered readily available, whereas hemicellulose, cellulose and lignin decompose much more slowly and are therefore not considered readily available. The composting process requires a certain fraction of readily available compounds to be present. For example, a pile of sawdust will not generate much heat compared to a similar sized pile of sawdust and biosolids. If the amount of readily available carbon is too high, rapid oxygen depletion (i.e. anaerobic conditions) and odor generation can result.

In general, the older the plant tissue, the less energy or readily available substrate is present. Small particle sized materials will also be more readily available for microbial consumption. Animal manures have a high content of readily available substrates, whereas wood chips are not very available. A continuum of relative carbon availability is presented below:

Raw wastewater solids = grass clippings > Green Leafy Vegetation > Digested

Biosolids = Brown Leafy Vegetation > Harvested Lagoon Biosolids > Chipped Brush and Twigs = New Sawdust > Old Sawdust > Wood Chips (Hog Fuel).

Nutrient Content

Inorganic nutrients such as nitrogen, potassium and phosphorous are required for microbial growth. In some mixes, nitrogen can be limiting. Yard debris collection during the winter months, for example, can have low nitrogen content. All other nutrients are typically present in sufficient quantity. As a general rule of thumb, the ratio of carbon to nitrogen (C:N ratio) should be approximately 30:1. A lower C:N ration can result in the production of odorous nitrogen containing compounds such as amines and ammonia, during composting. At higher C:N ratios, nitrogen may not be sufficient for active, thermophilic composting. However, initial mixes with C:N ratios as high as 60:1 have been noted to compost quite well. More significant than C:N ratio is the microbial availability of the carbon and nitrogen.

pH

Either excessively acidic or basic conditions can inhibit biological activity. Initial pH outside of the desired range of 6 to 7.5 should be adjusted unless demonstrated to perform adequately in pilot testing operations.

Visual / Qualitative

Trained and experienced compost facility operators can utilize simple qualitative tests as aids to operations. The visual appearance of the material at all phases of the mixing and composting process provides valuable insights into the status of the process. Color, moisture, particle size and void spaces, absence of mix “balls” and odor are useful visual / qualitative indicators. Of primary use during the initial mix operation are the squeeze test for free moisture, the observed thoroughness of mixing and the adequacy of void spaces in the mix.

Process Control Monitoring

Process monitoring entails the regular collection of data pertinent to the composting process. In addition, the data should be examined to determine if and what process adjustments need to be made. The following parameters should be monitored on a regular basis:

• Decomposition

• Bulk Density

• Moisture Content

• Oxygen Content

• Temperature

• Qualitative Parameters: Odor, Color and Texture

Decomposition

Maintaining optimum decomposition rates will reduce processing time and improve product quality. Optimum decomposition rates are obtained by providing an initial mix with sufficient carbon and nutrients and maintaining adequate temperature, moisture and oxygen levels. In general, decomposition occurs over two phases.

The first phase, described as the thermophilic phase (or active phase) is evident by temperatures greater than 40 oC (105 oF). This phase is when the majority of the ergy source is used (simple sugars, carbohydrates, and fats) which in this case is supplied to a significant degree by the biosolids. As the energy is used, heat is produced as a by-product.

The elevated temperatures increase the kinetics of the system. The higher temperatures along with adequate moisture and oxygen levels also encourage the growth of aerobic microorganisms. This is significant, as aerobic decomposition occurs at a faster rate than anaerobic decomposition and has far lower odor potential.

If all other environmental conditions are optimal, temperatures dropping into the mesophilic range (less than 40 oC) indicate microbial respiration or decomposition rates have been reduced and the composting process has entered the second phase of decomposition, called the curing phase. The first (active) phase of composting may last for a few weeks to a few months, depending on the substrates composted and the conditions provided. The second (curing) phase can take upwards of a few months before a mature final product is produced. Decomposition is assessed by evaluating several parameters throughout the process and measuring the stability of the final products. The following parameters are used to assess decomposition during processing.

• Volume Reduction

• Volatile Solids Reduction

• Respiration Rate

Volume Reduction – As the material degrades, the volume of the pile decreases.

With the aerated static pile process, this volume reduction is easily determined by monitoring pile height. For a consistent long-term program, the volume reduction could be correlated with other degradation parameters for use as an indicator of pile status.

Volatile Solids Reduction – A reduction from initial to final volatile solids of 50 to 60 percent is indicative of a stable compost product.

Respiration Rate – Respiration rate can be used as an indicator of biological activity throughout the composting process. This testing is discussed in a later section.

Bulk Density

Bulk density is a simple means of assessing porosity. The denser the material, the lower the porosity. Bulk density can be readily determined by weighing a bucket or other container of a known volume containing the material. The bulk density of composting material should remain less than 1200 pounds per cubic yard (pcy), with an initial target value of 900 pcy.

Moisture content should be maintained between 40 and 65 percent throughout the composting process. If material is too dry, water can be added (although this is difficult with the ASP method of composting). If the material becomes too wet, additional bulking agent can be added to the initial mix, or in some cases, the aeration rate can be increased to drive off excess moisture.

Oxygen Content

Aerobic composting is a process that provides continuous oxygen supply in the mix void spaces at normally greater than 5% and greater than 15% during the aeration or turning cycle. The oxygen content can be monitored on a routine basis, although this requires specialized equipment.

Temperature

The use of temperature as a method of monitoring the composting process is the most common and most convenient. Temperature measurements indicate several composting performance goals and may be used to:

• Determine the suitability of the initial mix – if the initial mix has the appropriate physical and chemical characteristics, then thermophilic temperature should be achieved within three to five days and maintained for several weeks thereafter.

• Document the achievement of pathogen reduction requirements.

• Document temperatures required for weed seed destruction.

• Indicate oxygen-limiting conditions – a drop in temperatures during the active process, between pile turnings indicates oxygen is limiting or excessive aeration turning is provided.

• Determine compost stability – a 20 cubic yard pile of cured product should not reheat more than 20 oC above ambient temperatures.

Qualitative Parameters

Assessing the compost visually and by smell and feel can provide valuable insight to the process. It is generally recommended that the sample being assessed be taken from the pile interior (deeper than 36-inches) with a front-end loader. The senses can be used to assess the following parameters:

• Moisture content – composting material should feel moist but not excessively wet. When squeezed in a fist, free water should not drip from the material.

• Aeration – a sour or pungent odor is an indication that the pile is anaerobic and that it should be turned more frequently or the blower-operating period (i.e., frequency and duration) should be increased.

• Porosity – the compost should have a granular, chunky appearance. A fine texture is an indication the material may not be sufficiently bulked.

Final Product Quality

The following parameters should be evaluated to determine final product quality:

• Particle Size Distribution

• Nutrient Content

• Weed Seed Viability

• Salinity

• Foreign Matter Content

• pH

• Visual / Qualitative

Particle Size Distribution

The particle size distribution of the compost product is important for most uses of the material. The particle size of the product is determined primarily by the screen size used in post-processing the material. However, the visual effect and distribution below the screens’ threshold size is greatly influenced by the bulking material used.

For example, all of the sawdust used for bulking normally ends up in the product, whereas hog fuel will largely be screened out of the product. Yard debris, when used as a bulking material, contributes a significant fraction to the product and has a strong impact on the product appearance and character. Branchy yard debris may result in twigs “spearing” through the screen opening, resulting in a coarser finished product.

Nutrient Content

Compost is considered a soil conditioner and is used primarily to improve the organic matter content of soil. However, depending on the feed stocks and process used, compost can have an appreciable nutrient content. Compost with a “high” nutrient content is considered better in quality and potentially has a higher market value. The nitrogen content of compost is especially significant as it is the plant nutrient required in greatest quantity.

More important, the addition of immature compost to soil may result in the microbial “tying-up” or immobilization of inorganic nitrogen. The carbon to nitrogen ratio (C:N) is one means of assessing the fate of inorganic nitrogen when compost is used. In general, a C:N ratio in compost feedstock above 30 may result in the immobilization of inorganic nitrogen. Conversely, a C:N ratio below 30 typically results in the mineralization or “release” of inorganic nitrogen, which is desirable.

Additional nutrients required for plant growth include: K, P, Ca, Mg, plus a variety of nutrients needed in trace amounts. Trace nutrients include: Al, B, Cu, Co, Fe, Mn, Mo and Zn. A balanced supply of these nutrients is required for good plant growth. If the supply of these essential nutrients is inadequate or excessive, the growth of plants is abnormal or stunted. Compost has been shown to be an excellent source of trace nutrients, within the desired range.

Weed Seed Viability

For most uses of compost, it is very important that weed seeds not be present.

Weed seed viability is determined by placing a sample of compost in an enclosed container and maintaining the moisture content between 45 and 55 percent, and temperature between 65 and 75 o F. The containers should be examined several times a week for the presence of germinating seeds. No viable weed seeds should be found.

Salinity

Organic material such as composts vary greatly in salinity (soluble salt content). The two deleterious effects most often encountered are excess total salts and high sodium levels. Excess total salts can inhibit the germination and growth of plants.

High sodium levels, and to a lesser degree potassium levels, cause dispersion of soil particles, poor soil structure, and reduced infiltration rates.

A simple method of evaluating salinity is to measure the electrical conductivity (EC) of the material. Estimating soluble salt content by measuring EC generally is accurate enough to evaluate the effects of organic material application on land. Salinity tolerance can range from 2 mmhos per cm for plants that are salt sensitive, to 18 mmhos per cm for salt tolerant plants. A desirable product range is from 2 to 6 mmhos per cm. Studies have shown that salts do tend to leach out of the soil / compost mix, thereby reducing the potential adverse impacts. However the salts can accumulate within the root zone with multiple and excessive applications over time.

Foreign Matter Content

The presence of significant visible foreign matter such as plastic, glass and metal that relates the product to its source of origin can greatly reduce the marketability of the product. The final product may be tested to assure that the amount of foreign matter present is less than 0.5 percent on a dry weight basis. However, visual examination of the product will generally suffice.

Most plants have a range of tolerable pH. The product pH should be provided to users to assure proper usage. Product pH outside of normal ranges may indicate the need for initial mix or process adjustments. In most cases, the pH of a finished compost material (regardless of its initial pH as an initial mix) is 6 to 7.5.

Visual / Qualitative

Assessing the compost visually and by smell and feel can provide valuable insight to the product quality. The “market” generally perceives the best quality finished compost materials to be dark brown to black in color, to have a forest duff odor, and to be uniformly fine in texture.

WAC 173 350-220(4)(e)(ii)(H) Pathogen Reduction Plan

Pathogen / Vector Reduction

"Exceptional quality biosolids" means biosolids that meet the concentration limits in Table 3 of WAC 173-308-160, the Class A pathogen reduction requirements in one of WAC 173-308-170 (2)(a) through (f), and the vector attraction reduction requirements in one of WAC 173-308-180 (2) through (7).

The Environmental Protection Agency (EPA) conducted exhaustive risk analyses involving the processing and use of composted biosolids products. Upon completion of this work, the EPA established the minimum criteria used for meeting human health objectives. These criteria are stated in the body of regulation entitled 40 CFR Part 503.32, (also referred to as the “503 Regulations”). The technical term for the minimum criteria to produce a Class A compost is “Process to Further Reduce Pathogens” or PFRP.

The PFRP criteria for the aerated static pile and in-vessel methods of composting biosolids are stated as follows:

Pile temperatures shall be maintained at 55ºC (131ºF) or higher for a minimum of 3 days (i.e., piles must be covered to ensure minimum temperatures throughout the pile); and

• Fecal coliform must be less than 1,000 most probable numbers (MPN) per gram total solids (dry-weight-basis);

• Salmonella sp. Bacteria must be less than 3 MPN per 4 grams of total solids (dry-weight-basis).

To control vectors, it is also required that the temperature in the compost pile be maintained above 40ºC (104º F) for 14 days after PFRP has been achieved.

While these criteria are specific to biosolids, they have also been generally adopted for other feedstock materials that potentially contain human pathogens. Fort Lewis will use these criteria to produce an Exceptional Quality/ Class A (WAC 173-308 Regulations) finished compost product.

WAC 173 350-220(4)(e)(ii)(I) Sampling and Analysis Plan

Fort Lewis will use the facility to compost organic wastes received from within the Fort and at other affiliated local federal installations. Organic wastes to be processed will include: green waste, and horse manure, biosolids, chipped wood and paper.

Testing Procedures and Quality Assurance Project Plan (QA Plan) serve two important functions:

• First, the plan establishes the requirements and procedures for the monitoring program. Monitoring the composting process is needed to verify that the finished compost meets or exceeds criteria established for an exceptional quality compost product and to ensure that product quality is consistent and predictable over time.

• Second, the completed plan facilitates communication between Fort Lewis management, the operations personnel who collect and ship the samples, the analytical laboratory, and the lead agency, Tacoma/Pierce County Health Department. This plan will also be useful for training new staff who will be working on compost monitoring, with an emphasis on assuring continuity between sampling / testing events and results.

This plan is subject to change to keep the facility in compliance with current state and local regulations. For this reason, this plan should be reviewed annually and amended as needed, with concurrence from the lead regulatory agency.

Organization and Responsibilities

Facility Contact Information

Facility Owner/Operator: Fort Lewis

Primary Contact: Alternate Contact:

Ken Smith – Branch Chief Ron Norton Fort Lewis Public Works

IMNW-LEW-PW MS-17

Box 339500 Fort Lewis, WA 98433-9500 same

(253) 966-3275 (253) 966-6452 ken.smith1@us.army.mil ron.norton1@us.army.mil

Responsibilities: Management of daily facility operations; Oversee compost operations; Maintain permits; Responsible for all on-site activities, including active composting, process monitoring, sampling, coordinating laboratory testing, and annual reporting.

Compost Consultant

Name: Mr. Peter Moon, P.E., Price-Moon Enterprises, Inc., Address: 127 Avenue A, Suite 2D, Snohomish, WA 98290 Telephone / Fax: (360) 563-6709 / (360) 563-5790 E-mail: peter@o2compost.com

On-Site Measurements

The lead operator will conduct specific on-site tests on a daily or weekly basis (as specified in Figure 4 of this QA Plan) to monitor the composting process and maintain desired conditions within the compost pile and the compost facility in general. These on-site measurements include:

• Pile Temperature

In addition certain tests that should be made on the curing pile and finished compost may be performed on-site to minimize laboratory costs. These tests include:

• Pile Temperature

• Compost Stability – Respiration rate (Solvita™)

Pile Temperature

Pile temperatures will be taken daily in each pile until such time as that particular pile satisfies PFRP conditions. Pile temperatures will then continue to be taken on a daily basis to confirm that vector attraction reduction (VAR) criteria have been met, and to monitor the on-going composting process.

Pile temperatures will be taken at three zone locations on the pile (see figure 3).

The three zones are identified as the head (closest to the blower fan), mid, and toe (zones 1, 2, & 3 respectively). Temperatures will be taken at three different levels at variable locations within each zone to include the following:

• Temperature monitoring probes will be inserted into the piles at depths of 18 and 36 inches.

• Temperatures will be monitored at three levels in the pile (top, mid, and bottom), see figure 3 for level locations. Care must be taken to take temperatures readings at least 18 to 24 inches from the top and bottom of the pile (depending on the thickness of the bottom plenum) to avoid placement of the temperature probe in the bottom plenum and top biofilter material layers.

• Temperatures will be monitored in three areas of the pile (zones 1-3). The areas of the pile to be monitored will be identified as the head (area closest to the blower fan), mid, and toe. The ends of the pile will be monitored in addition to other representative locations in the three areas of the pile.

Temperature readings will be recorded for each pile and each designated location on a form completed and maintained by the lead operator, and kept at the compost facility. Compost pile monitoring forms are found in Appendix B.

ZONE 3 TOE ZONE 2 MID ZONE 1 HEAD

ZONE 3 ZONE 2 ZONE 1

FIGURE 3

TOP

MID

BOTTOM

COMPOST PILE TEMPERATURE

MONITORING ZONES

BLOWER FAN

The moisture content determination should be done periodically during on-going operations.

During the curing phase of composting, the moisture content will be taken periodically, both during process start-up and on-going operations.

Particle Size

During the start-up period, the particle size of the individual feedstocks should be checked regularly to establish the optimum grind size. Monthly observations will be adequate after start up.

Bulk Density

The bulk density of the initial compost mix will be determined monthly during on-going operations.

During the curing phase of composting, the bulk density of the finished compost will be taken monthly, both during process start-up and on-going operations.

During the active phase of composting, the pH of each pile will be measured regularly throughout start-up and when any new feedstock is introduced. This test is easily completed using a slurry of the compost with de-ionized water using litmus paper. The pH measurement will be taken monthly during on-going operations.

Compost Stability –Respiration Rate (Solvita™) Test Methods

At the end of the curing phase and prior to product determination, the Solvita Test Method will be used to determine compost stability.

Monitoring Equipment Calibration and Maintenance

Equipment for on-site testing and the appropriate calibration/standardization is listed in Table 2.

On-Site Monitoring Equipment and Calibration Information

Measurement Equipment Calibration Pile Temperature Compost thermometer Monthly or according to manufacturers instructions Moisture Content Oven that can be set to

105° F or microwave oven Check temperature during each measurement with oven thermometer. For microwave method compare results with lab moisture content results at least monthly.

Bulk Density Calibrated bucket (known volume – usually 5 gallons) and scale weighing at least up to 70 pounds – depending upon volume of container.

Check scale with calibrated weight (can be known volume of water) at least monthly. Accuracy need only be ± 1 pound for 5-gallon container.

pH Litmus paper or pH probe may be used on-site.

Follow manufacturer’s instructions for calibrating a pH probe. Check expiration date on litmus paper at each use.

Stability Solvita™) measurement of CO2 generation.

Solvita test kits must be used prior to expiration…