HomeMy WebLinkAbout2017-PilotStudyWorkPlan-Draft
Consulting Engineers & Geologists, Inc.
350 Hartnell Ave. Ste b
Redding, CA 96002 September 2017
530-221-5424 516042
Pilot Study Work Plan
Waste Discharge Requirements
Order No. 93-083
Prepared for:
North State Rendering Company
15 Shippee Road, Oroville, California
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CONSULTING ENGINEERS & GEOLOGISTS, INC.
350 Hartnell Ave. Ste. B Redding, CA 96002 Phone 530-221-5424 info@shn-engr.com
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Reference: 516042
September 1, 2017
George Low, P.G.
Senior Engineering Geologist
Waste Discharge Requirement Unit
Central Valley Regional Water Quality Control Board
364 Knollcrest Drive, Suite 205
Redding, CA 96002
Subject: Pilot Study Work Plan – North State Rendering Company
WDR Order No. 93-083
Dear Mr. Low:
Please find enclosed the Pilot Study Work Plan for the North State Rendering facility prepared by
SHN Engineers & Geologists on behalf of North State Rendering. This pilot study work plan
outlines the procedures and test methods for the use of septic wastes as a part of the current bio-
digester system.
Please provide your technical comments to SHN after which we will respond and incorporate them
into the work plan as appropriate and then review with North State Rendering prior to finalizing
the work plan.
Should you have any questions about this work plan, please contact Eric Schneider at SHN’s
Redding offices at (530) 221-5424.
Sincerely,
SHN Engineers & Geologists
Eric Schneider, PE
Senior Civil Engineer
Enclosures: Pilot Study Work Plan
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Reference: 516042
Pilot Study Work Plan
Waste Discharge Requirements
Order No. 93-083
Prepared for:
North State Rendering Company
15 Shippee Road
Oroville, California
Prepared by:
Consulting Engineers & Geologists, Inc.
350 Hartnell Ave. Ste. b
Redding, CA 96002
530-221-5424
September 2017
QA/QC:
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Table of Contents
Page
1.0 Introduction .......................................................................................................................................... 1
2.0 Background ........................................................................................................................................... 1
3.0 Bio-digester ........................................................................................................................................... 1
3.1 Bio-Digester System Operations ........................................................................................... 2
4.0 Pilot Study Activities ........................................................................................................................... 3
4.1 Goals ......................................................................................................................................... 3
4.2 Septic Waste Delivery ............................................................................................................. 3
4.3 Storage and Solids Removal .................................................................................................. 3
4.4 Septic Waste Volume Schedule ............................................................................................. 4
5.0 Sampling and Monitoring ................................................................................................................... 5
6.0 Reporting ............................................................................................................................................... 6
List of Illustrations
Figures Follows Page
1. Site Map .................................................................................................................................... 1
2. Facility Map ............................................................................................................................. 1
Appendix
Appendix A - Wastemaster TSF-1 manufacture product specifications sheet
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Abbreviations and Acronyms
CVRWQCB Central Valley Regional Water Quality Control Board
NSR North State Rendering
SHN SHN Consulting Engineers & Geologists, Inc.
WDR Waste Discharge Requirement
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1.0 Introduction
This Pilot Study Work Plan (PSWP) has been developed for the North State Rendering Company (NSR)
to establish the procedures and test methods for the addition of septic waste into its existing waste
stream at its Shippee Road bio-digester facility. The existing waste stream at the NSR facility consists
of a variety of commercial and retail food wastes that is used to produce bio-gas. The PSWP will
evaluate if the addition of septic waste has any negative impact on the production of bio-gas and if
there are negative impacts to the wastewater effluent from the facility.
2.0 Background
The NSR facility consists of a former rendering facility, bio-digester and pond system. Rendering at the
facility was discontinued in May 2016 and the primary operation at the facility since that time is the use
of the bio-digester to convert food wastes to bio-gas. North State Rendering is currently operating
under WDR Order No. 93-083 and is in the process of updating the facilities waste discharge
requirements (WDR) with the Central Valley Regional Water Quality Control Board (CVRWQCB) to
reflect the current operations. The facility is located at 15 Shippee Road, Oroville, California. Figure 1
illustrates the location of the facility. Figure 2 provides a site map of the facility showing the bio-
digester and wastewater ponds locations.
Septic waste disposal in Butte County and the surrounding areas has been accepted at the Neal Road
Landfill for several decades which is operated by Butte County. The Neal Road Landfill is slated to
stop accepting septic waste sometime in September 2017 and septic haulers will have to travel to
disposal locations outside of Butte County as no other septic waste disposal facility exists within the
county. The NSR pilot study will help to determine if the NSR facility can process septic waste through
the bio-digester in safe and responsible manner that meets regulatory requirements.
North State Rendering is excited to present this PSWP in the anticipation that the NSR facility would
eventually be able to provide some level of community beneficial service through the acceptance and
treatment of septic waste into a usable commodity.
3.0 Bio-digester
The bio-digester is currently used to handle a variety of food waste products such as grease trap
material, commercial processed food wastes and other waste materials. The bio-digester converts the
material brought to the facility to produce methane gas (bio-gas). The following types of wastes are
typically processed by the bio-digester:
• Agricultural fruit waste
• Cheese whey
• Grease trap waste
• Commercial waste from pasta and salami manufacturing facility
• Cow Manure
• Food waste
• Glycerin from Biodiesel facility
• Waste from olive processing facilities
• Wastewater from rendering grease trap material
FigureConsulting Engineers& Geologists, Inc.
NORTH STATE RENDERING CO LOCATION MAP
USGS MAP SHIIPPEE
March 2017 516042-FIGURES
SHN 516042
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REPORT OF WASTE DISCHARGE
15 Shippee Rd, Oroville CA
\\Redding\Projects\2016\516042-WDR-Rendering\Dwgs, SAVED: 3/31/2017 2:24 PM ESCHNEIDER, PLOTTED: 4/3/2017 2:58 PM, ERIC SCHNEIDERN
SCALE
LOCATION MAP
N
Figure\\Redding\Projects\2016\516042-WDR-Rendering\Dwgs, SAVED: 4/11/2017 4:48 PM ESCHNEIDER, PLOTTED: 8/31/2017 1:53 PM, ERIC SCHNEIDER
Consulting Engineers& Geologists, Inc.2MARCH-2017FILENAME-516042-FIGURESNSCALENORTH STATE RENDERING COREPROT OF WASTE DISCHARGE15 Shippee Rd, Oroville CASITE MAPFACILITY LAYOUT516042LEGEND
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The source of the influent food waste stream going into the bio-digester is collected from businesses
around northern California. NSR has its own trucking fleet that collects waste and also has local
haulers delivering waste to the site on a daily basis. NSR is the only facility in northern California
providing this service, which is a vital service to the community for the disposal food waste.
The food waste is mixed into a slurry and is then fed into the bio-digester which breaks down the food
waste and produces bio-gas that is used for electrical generation and is compressed (compressed
natural gas) for use as vehicle fuel. The byproduct of the bio-digester (wastewater effluent) is then
transferred into the existing process wastewater pond system.
3.1 Bio-Digester System Operations
NSR operates a two-stage, mesophilic anaerobic digestion system which handles a variety of organic
wastes. The bio-digester system is composed of three tanks (Tank 1, Tank 2, and Tank 3) plumbed in
series. Organic wastes are input via a solid hopper or liquid reception pit which homogenizes and
pulverizes accepted materials. Homogenized waste is then pumped into the bio-digester (also referred
to as a “reactor”) in which the first three stages of anaerobic digestion occurs under acid (pH 4.5)
conditions. In the first stage, particulate organic molecules are solubilized and converted into
monomers by hydrolyzing bacteria. Monomers are then converted into volatile fatty acids in the
second stage known as acidogenesis. The third stage, known as acetogenesis, is the biological
conversion of volatile fatty acids into acetic acid, carbon dioxide, and hydrogen. These three stages all
occur in Tank 1.
The fourth stage of digestion occurs in both Tank 2 and Tank 3, which are separate and neutral pH
reactors (pH 7.5), involving a group of archaea known as methanogens. These methanogens utilize
either acetate or carbon dioxide and hydrogen to produce methane and carbon dioxide. The
biologically produced methane (bio-gas) is then utilized for the production of electricity and is
compressed for use as a vehicle fuel. The byproduct of the bio-digester process is wastewater that is
then disposed of into the process wastewater ponds.
The Bio-digester process takes between 40 to 60 days from start to finish, to convert food waste to gas
depending on the consistency and strength of the waste slurry that is delivered to Tank 1. The total
volume the Bio-Digester system holds is approximately 950,000 gallons. Tank 1 (acid tank) has an
estimated volume of 211,000 gallons, Tank 2 (pH neutral tank) has an estimated volume of 211,000
gallons of capacity and Tank 3 (pH neutral tank) has an estimated volume of 528,000 gallons of
capacity.
The estimated current daily average in feed volume of slurry into the bio-digester system is
approximately 16,000 gallons per day, delivered twice a day based on the rate of conversion in the bio-
digester system. As the bacterial community in the reactors changes over time in response to a new or
varying types of waste, organisms best equipped to degrade that waste type begin to florish.
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4.0 Pilot Study Activities
North State Rendering proposes to utilize septic waste that will be diverted from Butte County’s Neal
Road Landfill as part of its waste stream for the continued generation of bio-gas. This section describes
the pilot study goals and activities, with Section 5.0 describing the Monitoring activities to evaluate the
effluent the overall process and to determine if the wastewater effluent meets WDR levels.
4.1 Goals
The goal of the pilot study is to test the theory that the existing bio-digester can process a mixture of
both septic waste and food waste and produce and produce both usable bio-gas and create an
acceptable wastewater effluent for disposal into the existing process wastewater ponds. By performing
the pilot study, data will be collected to determine if the bio-digester is an effective means of treatment
of septic wastes while producing usable bio-gas. Wastewater effluent data will also be analyzed to
determine what levels of constituents are present in the effluent, and if they are present within limits
established for the facility by the WDR.
4.2 Septic Waste Delivery
Septic waste will be delivered by septic haulers which typically have an estimated 3,000 gallon tank
capacity per truck. Septic haulers typically pump septic tanks from residences within the surrounding
area. Upon arrival at NSR, the septic truck will first be weighed at the scales on site. From there, the
truck will then drive to the bio-digester concrete pit area where it will un-load. The septic hauler will
be present while the septic content is pumped from the tank on the truck through the Speco Solid-
Liquid separator and then into the bio-digester concrete pit. Once the tank is empty the truck will
drive back over the scales and weigh out. Records will be kept of the date and amount delivered to the
facility. Septic will not be stored on site except in bio-digester concrete pit area just prior to supply to
Tank 1.
4.3 Storage and Solids Removal
Prior to the septic waste entering in the bio-digester pit the material passes through a mechanical
effluent pre-treatment/screen system. The NSR facility uses the Wastemaster TSF-1, which is a
mechanical screening system that removes non-digestible solids, such as rock and plastic. See
Appendix A for the Wastemaster TSF-1 manufacturers’ product specification sheet. As the septic
passes through a screen the solids are collected and are removed by a conveyor screw. The conveyor
screw takes the solids to a collection compartment which has a compactor that dewaters the solids. The
removed water from the solids returns to the bio-digester concrete pit. The solids (considered
municipal waste now) are then removed after dewatering to a bin that is emptied into a trash
dumpster. The dumpster would be emptied on a regular basis by the local waste management
company (Recology). The municipal solid waste is then transported appropriate landfill.
The volume of solids and debris removed from the waste stream is projected to be minor, less than 30
cubic yards per week. A single trash dumpster is projected to provide ample storage space. The trash
dumpster will have a lid to prevent stormwater from contacting solids and debris and to reduce
vectors.
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The resultant septic waste will be briefly stored onsite in the bio-digester concrete pit, which has a
capacity of approximately 17,500 gallons. The septic will be blended in the pit with the existing food
waste stream that comes into the NSR facility daily (refer to Section 3) to make a slurry that is fed into
the bio-digester.
4.4 Septic Waste Volume Schedule
The following describes the proposed processing schedule of introducing septic waste to the bio-
digester system. The use of septic waste in a bio-digester system is not a new idea and has been done
before at other facilities in California and the US. It is presumed that the NSR Facility bio-digester will
have a positive response to the introduction of septic to the current waste stream. The bio-digester
currently processes an estimated 16,000 gallons of slurry a day. The pilot study will cautiously start the
introduction of septic into the bio-digester at a reduced rate and eventually work up to a potential of
49% of the intake volume (about 7,840 gallons) into the bio-digester. The septic volume introduced into
the waste stream will substituted for the current food waste volume at a direct portion. So if 3,000
gallons of septic is added daily then a reduction of 3,000 gallons of other food waste will occur and the
bio-digester will continue to process an estimated 16,000 gallons daily. North State Rendering will cut
back shipments of food waste being delivered to the site to accommodate the septic waste. Also, it is
unknown at this time what the actual demand for septic waste delivery will be from local waste
haulers. Staff at NSR are making separate efforts to reach out to waste haulers to determine if the
location and eventual costs will be viable.
To ensure that the introduction of septic waste into the bio-digester waste stream is not inhibiting
production of bio-gas, the facility will follow the following steps.
Introductory Period
1. The introductory volume of septic will be approximately 3,000 gallons daily.
2. The introductory time period is 10 days.
3. Each day on site personnel will assess the pH in Tank 1; the pH tells how the digester waste
stream is performing in the tank. The pH should be around 4.5, with normal variations. In
Tank 1 the complex and insoluble organic material hydrolyze into monomers and organic
acid.
4. At the end of the 10 day initial time period, an assessment will be made by NSR staff as to
how the septic is performing. In the event that the septic is not performing as desired
adjustments will made and another 10 day introductory period will begin. This will
continue to until an acceptable balance can be reached before moving forward with an
increase in volume of septic. Adjustments of waste combinations will be recorded.
Regular Period
After the introductory daily volume of 3,000 gallons is found to be processing and performing
satisfactory within the bio-digester system, the volume of septic will be increased.
1. The volume of septic will increased to a maximum of 49% of the 16,000 gallon daily
production level (approximately 7,840 gallons).
2. The bio-digester system and overall production in the tanks will continue to be monitored.
Typical monitoring of the system entails pH and residence time in each tank. Production
monitoring consists of the volume of methane production.
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3. At 16,000 gallons per day waste stream going into the 951,000 gallon bio-digester system, it
will take about 60 days to completely change the contents of the bio-digester and fully
process the waste stream (including the septic waste).
4. Sampling will occur at both the influent and effluent side of the bio-digester system.
Samples of the influent slurry and effluent wastewater will be taken prior at the start of
regular production, then again at the 50% level of bio-digester volume change, again at
100% level of bio-digester volume change, and 30 days after 100% level of bio-digester
change.
During the evaluation of the septic pilot study results septic will continue to be processed until an
approval or dismissal of the process is completed.
5.0 Sampling and Monitoring
Sampling and monitoring of the bio-digester system is imperative. Throughout the pilot study the bio-
digester will be monitored by NSR staff to make sure the septic is processing through the system
adequately, and that the bio-digester is not “upset” with the introduction of septic. NSR will be
recording load ticket of septic haulers to monitor the amount of septic waste being delivered. Records
of the daily volumes of slurry being pumped into the bio-digester and effluent discharge from the bio-
digester will be reported.
Sampling will occur of the slurry and effluent from bio-digester prior to the start of regular production
(day 0 after introductory period), 50% level of bio-digester volume change (30 days), 100% level of bio-
digester change (60 days), and 30 days after 100% level of bio-digester change (90 days).
Grab samples of the slurry and effluent will be tested for the following constituents listed below in
Table 1 and 2. The influent slurry will be sampled from the concrete pit mixing area prior to entering
the bio-digester and wastewater effluent will be sampled at an extraction port on the effluent pipe from
Tank-3. Samples will be taken to Basic Laboratory a CA-ELAP certified laboratory for testing.
Table 1
Proposed Effluent Analytical Suite
General Chemistry Metals
Hardness Aluminum
pH Arsenic
Alkalinity as CaCO3 Cadmium
Bicarbonate Calcium
Hydroxite Copper
Chloride Iron
Nitrate as N Lead
Nitrite as N Magnesium
Sulfate as SO4 Manganese
Specific Conductance Mercury
Fixed Dissolved Solids Potassium
Total Dissolved Solids Sodium
Total Suspended Solids Zinc
BOD – 5 Day
Chemical Oxygen Demand
Settleable Solids
Total Kjeldahl Nitrogen
Ammonia as N
Total Phosphorus as P
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Table 2
Additional Analyses
% solids
Ecoli
Total Coliform
6.0 Reporting
Upon receiving the analytical data from the four (4) sampling times, SHN will prepare a report
summarizing the analytical results, volume of septic processed, total volume of waste processed,
volume of effluent from bio-digester, and recommendations.
A
Wastemaster TSF-1 Manufacture Product
Specifications Sheet
WASTE WATER & SLUDGE TREATMENTCompact Plants for Mechanical
Effluent Pre-Treatment
WASTEMASTER® TSF-1
WASTEMASTER® TSF-1 is a combined machine for the separation of solids present in effluents and the
compaction and de-watering of the extracted solids. It is designed to be fed by a pump or by gravity.
The suspended solids are retained by the screen, increasing the liquid level in the front part of the screen.
At this point the screw starts operating, cleaning the screen by means of brushes fixed on the outer part
of the screw flighting, removing the material, and then de-watering and compacting it.
The machine consists of the following parts:
• Screen;
• Conveyor screw;
• Compactor.
The conveyor screw consists of a shaftless spiral which collects the solids from the bottom of the screen
conveying them without risk of clogging.
The compactor in the upper part, equipped with washing section for lowering organic fractions, uses the
conveyor screw for compaction and de-watering of the screenings.
SCREW SCREEN IN SELF-SUPPORTING TANK
Technical features
- TSF-1 has a sturdy metal framework, (completely enclosed structure
complying with safety regulations and preventing odours) manufactured
entirely from 304L / 316L stainless steel
- Shaftless conveyor screw manufactured from 304 / 316 stainless steel or
special high-resistance steel
- Flow rates up to 500 m3/h (300 c.f.m.)
- Solids extraction up to 0.18 dm3/s
- Screens have a special mesh suitable for particular characteristics of waste
water and solids
- ATEX GAS II Motors AvailableCompact Plants for Mechanical Effluent Pre-TreatmentWASTEMASTER® TSF-1Polymer Outlet with Compacting Washing System
Inlet Screen Basket with Splash Guard
TSF-1 Outlet Top View
Insulated Discharge Module
Accessories
- Bag clamping system
- Endless tube
- Level Sensor
- Solenoid Valve
Overall Dimensions
Benefits
Compact design;
Screening, conveying and compacting in a single unit using one drive only;
Easy installation, low maintenance and low operating costs;
Outdoor installation with optional anti-freeze accessories;
No clogging even with fibres thanks to shaftless screw design.
Dimensions in mm
MODEL A B C ØE G Hd I L M N O P S W L
Total
TSF1 300 2,141 2,595 2,030 219 170 933 645 934 200 936 1,56 1,03 480 236 2,755
TSF1 400 2,647 3,031 2,370 219 230 1,229 765 1,204 200 1,18 1,81 1,3 580 236 3,245
TSF1 500 2,505 2,978 2,342 219 250 1,240 850 1,254 250 1,23 2,03 1,4 680 236 3,201
Application
063002408 May 2015 Rights reserved to modify technical specifications.www.wamgroup.com