MEMORANDUM

From: William Swietlik, USEPA/OW/OST Ph: (202) 566-1129, Swietlik.william@epa.gov

To: Public Docket for the Preliminary 2016 Effluent Guidelines Program Plan EPA Docket Number EPA-HQ-OW-2015-0665 ( http://www.regulations.gov )

Date: October 29, 2015

Re: Hydrogen Sulfide Releases Report ed to the Toxics Release Invent ory (TRI) in 2013

As part of EPA’s Office of Water Engineering and Analysis Divis ion (EAD) 2015
Annual Review of effluent limita tions guidelines and standards (ELGs), EAD performed a toxicity ranking analysis (TRA) of all industrial categories, i ncluding those subject to existing ELGs and those not currently re gulated by ELGs, consistent with the methodology described in
Section 2 of the 2015 Annual Effluent Guid elines Review Report (2015 Annual Review Report) (U.S. EPA, 2016)

. EAD used the TRA to identify and prioritize for further review, categories discharging high levels of toxic pollutants rela tive to other c ategories. In performing the TRA, EAD relied on discharge monitori ng report (DMR) data pulled fro m the Integrated Compliance Information System for the National Pollutant Discharge Elimina tion System, and Toxics Release Inventory (TRI) data . EAD downloaded the 2013 DMR and T RI industrial rankings data from the DMR Pollutant Loading Tool 1 and performed a quality review of the data. During its review of the 2013 TRI data, EAD not ed that hydrogen sulfide wa ter releases accounted for approximately 40 percent of the t otal 2013 TRI toxic-weighted p ound equivalents (TWPE). 2 Hydrogen sulfide has not been inc luded in or evaluated as part of EAD’s previous annual reviews, but is now included due to recent changes in TRI repor ting requirements.

This memorandum describes EAD’s quality review and evaluation o f the hydrogen sulfide data reported to TR I in 2013 and EAD’s methodology for incorporating these releases
into the 2015 Annual Review.

1.1 Background on Hydrogen Sulfide Reporting to TRI

Hydrogen sulfide was added to the T RI list of toxic chemicals i n a final rule published on December 1, 1993. On August 22, 1994, EPA issued an Administrat ive Stay of the reporting requirements for hydrogen sulfide to evaluate issues brought to the Agency's attention after promulgation of the final rule. T hese issues concerned the huma n health effect basis for the listing and the Agency's use of e xposure analyses in TRI listin g decisions. Although the final rule listing hydrogen sulfide unde r section 313 of the Emergenc y Planning and Community

1 See http://cfpub.epa.gov/dmr/psc_ranking.cfm

. 2 EPA evaluates the relative hazar d of category discharges by ap plying toxic weighting factors (TWFs) to annual pollutant discharges to calculate the total discharge of toxic pollutants as TWPE. See Section 2 of the 2015 Annual Review Report for more information on TWPE.Memorandum October 29, 2015 Page 2

Right-to-Know Act (EPCRA) rema ined in force, the stay deferred the reporting requirements for hydrogen sulfide while EPA complet ed its further evaluation (76 FR 64022).

From its further evaluation of t he environmental toxicity of hy drogen sulfide, EPA
determined that available data i ndicate that water with concent rations of more than 2.0 ug/L undissociated hydrogen sulfide w ould constitute a long-term haz ard to aquatic organisms despite its fate under certain environmental conditions (76 FR 64022). As a result, on October 17, 2011, EPA announced it was lifting the A dministrative Stay of the rep orting requirements for hydrogen
sulfide under Section 313 of E PCRA (76 FR 64022). Facilities we re required to report environmental releases of hydroge n sulfide to TRI beginning wit h the reporting year 2012, including releases to water.

1.2 Hydrogen Sulfide Properties, Generation, and Fate

Hydrogen sulfide is a soluble , colorless, highly poisonous, gas eous compound having the
characteristic odor of rotten e ggs. Its chemical and physical p roperties are summarized in Table

1.

Table 1. Physical and Chemical P roperties of Hydrogen Sulfide

Property Value CAS registry number 7783-06-4

Molecular formula H 2 S Molecular weight 34.08 Vapor pressure 15,600 mm Hg at 25/C Density 1.5392 g/L at 0/C, 760 mm Hg Boiling point -60.33/C Water solubility 3,980 mg/L at 20°C Log K
ow NA Dissociation constants pKa1 = 7.04; pKa2 = 11.96 NA: Not applicable Source: U.S. EPA, 2003

Hydrogen sulfide is a biologica lly active compound that is foun d primarily as an anaerobic degradation product of both organic sulfur compounds and inorganic sulfates. Sulfides are constituents of many industrial wastes such as those from t anneries, paper mills, chemical plants, and gas works. The anaerobic decomposition of sewage, s ludge beds, algae, and other naturally deposited organic mater ial is a major source of hydro gen sulfide (U.S. EPA, 1986).

When soluble sulfides are adde d to water, the y react with hydro gen ions to form the hydrosulfide ion (HS

- ) and hydrogen sulfide (H 2 S), the proportion of each depending on pH. The toxicity of sulfides derives pr imarily from hydrogen sulfide ra ther than from the hydrosulfide or sulfide ions. At pH 9, approximate ly 99 percent of the sulfide is in the form of HS

- ; at pH 7 the sulfide is equally divided between HS

- and H 2 S; and at pH 5 about 99 percen t of the sulfide is present in the form of H 2 S (U.S. EPA, 1986). In well aerate d water, hydrogen sulfide is readily oxidized to sulfates and biologi cally oxidized to elemental sul fur. In anaerobic water, microbial reduction of sulfate to sulfide can occur (WHO, 2003).Memorandum October 29, 2015 Page 3

According to the World Health Org anization, the major uses of h ydrogen sulfide include
its conversion into sulfur and s ulfuric acid and the manufactur e of inorganic sulfides, thiophenes, thiols, thioaldehydes, and thi oketones. It is used in dye manuf acturing, tanning, t he production of wood pulp, chemical processing, and the manufacture of cosmetic s (WHO, 2003). A draft Toxicological Profile for Hydrogen Sulfide and Carbonyl Sulfide published by the Agency for
Toxic Substances and Disease Re gistry (ATSDR, 2014) indicates t hat facilities where hydrogen sulfide is produced, used, or gene rated include petroleum refin eries, natural gas plants, petrochemical plants, coke oven plants, kraft paper mills, visc ose rayon manufacturing plants, sulfur production plants, ir on smelters, food processing plants , manure treatment facilities, landfills, textile plan ts, wastewater treat ment facilities, and tanneries. Hydrogen sulfide is also used as an agricultural disi nfectant, in the production of heav y water, and as an additive in lubricants and cutting oils. Hydr ogen sulfide may also be encou ntered in various industrial processes including the manuf acture of dyes and pigments, felt, and artificial s ilk; in farming, brewing, glue making, and rubber vu lcanization; and in lithogra phy and photoengraving. Discharges from these and other activities can release hydrogen sulfide to receiving waters (ATSDR, 2014).

1.3 2013 TRI Hydrogen Sulfide Data

In TRI, facilities report annual releases to the environment of each toxic chemical or chemical category that meets re porting requirements. TRI requir es facilities to report on-site releases to air, receiving wa ters, underground wells, disposal to land, and several other categories (direct releases). TRI also requi res facilities t o report the a mount of toxic chemicals in wastes
transferred to offsite locations , including releases to publicl y owned treatment works (POTWs) and other off-site locations, suc h as commercial waste disposal facilities (indirect releases). This
memorandum focuses on water release s directly to r eceiving wate rs and to POTWs.

EAD identified hydrogen sulfide a s a top TRI-re ported pollutant during its 2015 TRA. Hydrogen sulfide has a TWF of 2.8 and accounted for approximate ly 40 percent of the total TRI TWPE (excluding the point source categories for which EAD has r ecently revised ELGs). 3

EAD identified and further evalu ated five industrial point sour ce categories with 2013 TRI reported releases where hydrog en sulfide contributes a sign ificant portion of the category’s TWPE. Table 2 lists these point s ource categories and the perce ntage of their total TWPE attributed to hydrogen sulfide. Tab le 3 summarizes the reported 2013 TRI hydrogen sulfide releases by release type (i.e ., direct and indir ect releases).

3 EAD has recently rev iewed the following p oint source categorie s: 423 – Steam Electric Power Generating; 449 – Airport Deicing; and 450 – Construction and Development.Memorandum October 29, 2015 Page 4

Table 2. Top 2013 TRI Point Source Categories with Reported Hyd rogen Sulfide Water

Releases

Point Source Category Total

TWPE H 2 S TWPE Percentage of

Total TWPE
Attributed to

H 2 S Direct Indirect Total 430 – Pulp, Paper and Paperboard 4,280,000 1,170,000 964,000 2, 140,000 50% 419 – Petroleum Refining 580,000 27,700 163,000 191,000 33% 406 – Grain Mills 276,000 176,000 97,900 274,000 99% 432 – Meat and Poultry Products 213,000 35,900 133,000 169,000 79%

407 – Canned and Preserved Fruits and Vegetables Processing 68,700 - 64,200 64,200 93%

Total TRI TWPE for Top Categories with Reported Hydrogen Sulfide Releases 5,420,000 1,410,000 1,420,000 2,840,000 52%

Total TRI TWPE 7,160,000 1,440,000 1,430,000 2,870,000 40%

Table 3. Summary of 2013 TRI Hydr ogen Sulfide Water Releases by Release Type

Type of Release Number of Facilities Reporting H 2 S Releases Pounds of Reported H 2 S

Releases H 2 S TWPE Direct 146 513,000 1,440,000 Indirect 26 511,000 1,430,000

Total H 2 S Releases 172 1,024,000 2,870,000

Total TRI TWPE 7,160,000

As shown in Table 2, hydrogen sulfide releases from these five point source categories account for 99 percent of the hydr ogen sulfide TRI TWPE and 40 percent of the total TRI TWPE. Table 3 shows that the total reported quantity of hydroge n sulfide released (in pounds) is equally distributed between dir ect and indirect releasing facil ities. The data al so indicate that a higher number of direct dischargi ng facilities (1 46) reported r eleasing hydrogen sulfide as compared to indirect disch arging facilities (26).

EAD further investigated the 2013 TRI reported hydrogen sulfide releases by direct and indirect releases, as discusse d in the sections below. EAD eval uated the completeness, comparability, accuracy, and reasonableness of the data, as it relates to facilit ies reporting both
direct and indirect releases to w ater, and assessed the implica tions and use of the data for EAD’s
2015 Annual Review.

. 1.4 Hydrogen Sulfide Data Reported by Facilities with Direct Water Releases

As shown in Table 3, 85 percent of the facilities reporting wat er releases of hydrogen sulfide are directly dischargi ng to receiving wat ers. However, these facilities only account for approximately 50 percent of hydrogen s ulfide water releases rep orted to TRI in 2013. As part of the TRA supporting the 2015 Annua l Review, EAD contacted indust ry trade associations and companies with facilities reporti ng the greatest d irect release of hydrogen sulfide for the pulp and paper, grain mills, and meat and poultry products point source categories. EAD did not contactMemorandum October 29, 2015 Page 5

companies or facilities in the petroleum refining and canned an d preserved fruits and vegetables processing categories because a m ajority of the facilities in t hese categories reported indirect releases of hydrogen sulfide to P OTWs. Table 4 lists the compa nies EAD contacted and their
relevant facilities and releases . EAD contacted the companies t o 1) confirm their 2013 TRI hydrogen sulfide direct releases a nd 2) determine whether the r eported releases are based on direct measurements or estimates and accurately represent poten tial releases dire ctly to receiving

waters.

Table 4. 2013 TRI Direct Discharging Facilities Contacted

Point Source Category Firm Name Facility
Location Pounds of Reported

H 2 S Releases H 2 S

TWPE 430 – Pulp, Paper and Paperboard Georgia-Pacific Monticello LLC Monticello, MS 115,000 323,000 406 – Grain Mills Cargill Inc Wet Corn Milling Wahpeton, ND 62, 500 175,000 432 – Meat & Poultry Products T yson Fresh Meats Inc Hillsdale, IL 5,320 14,900 432 – Meat & Poultry Products Tyson Fresh Meats Inc Lexington, NE 3,350 9,380

432 – Meat & Poultry Products Tyson Fresh Meats Inc Columbus Junction, IA 2,220 6,220 432 – Meat & Poultry Products John Morrell & Co Sioux Falls, SD 1,600 4,490

Total TRI Direct H 2 S Releases 513,000 1,440,000

The pulp, paper and paperboard point source category accounts f or approximately 80 percent of the total direct rel eases of hydrogen sulfide report ed to TRI in 2013 as shown in Table 2. As part of the TRA, EAD cont acted the pulp, paper and paperb oard trade associations, American Forest and Paper Associ ation (AF&PA) and National Coun cil for Air and Stream Improvement (NCASI). The trade a ssociations contacted the Georg ia-Pacific mill in Monticello, MS to discuss the hydrogen sulfi de releases. The mill confirmed the 2013 TRI hydrogen sulfide releases of 115,000 pounds and stated t hat this value was based on direct measurements of the
treated effluent at the facil ity. Since 2013 the facility has i mproved their wastewater treatment system and releases have decreased to 32,000 pounds per year (S chwartz and Wiegand, 2014).

The Cargill, Inc. facility in W ahpeton, ND manufactures high f ructose corn syrup and has an onsite wastewater treatment pl ant with aerob ic and anaerobic systems. The facility contact confirmed the 2013 hydrogen sulfide r elease and stated that the hydrogen sulfide concentrations
are a result of the wastewater t reatment plant processes, not f rom manufacturing. To calculate the 2013 hydrogen sulfide release repor ted to TRI, the facility col lected four samples from their
outfall from the wastewater trea tment plant. Hydrogen sulfide c oncentrations from the four samples were averaged and then m ultiplied by the facility flow and number of days per year to calculate the total pounds per ye ar release reported to TRI (Ra zink, 2014).

The Tyson Fresh Meats contact confirmed the 2013 hydrogen sulf ide releases for all
three facilities listed in Tab le 4 and stated tha t the TRI rele ases are based on direct samples of soluble sulfide and correspondi ng pH values at each facility. T he facilities are not required to sample their effluent for hydr ogen sulfide, so a limited number of samples were collected for TRI reporting purposes. The contac t indicated the facilities ha ve a consistent effluent quality;Memorandum October 29, 2015 Page 6

therefore, the collected sampl es were assumed to be representat ive of their annual release. At all the Tyson facilities reviewed, the measured soluble sulfide con centrations were converted to hydrogen sulfide; the hydrogen sul fide concentrations were then multiplied by flow to calculate a total release per year for eac h facility. The company contact a lso stated that wastewater treatment processes at the Tyson facilities in Hillsdale, IL and Lexingto n, NE each include a covered anaerobic lagoon, biogas handling, a noxic processes, aeration p rocesses, secondar y clarification, chlorination, and dechlorination. W astewater treatment processe s at the Tyson facility in Columbus Junction, IA includes an uncovered anaerobic lagoon al ong with aeration processes, secondary clarification, chlorin ation, and dechlo rination (Dirk s, 2014).

The facility contact for John M orrell and Co. also confirmed t he 2013 hydrogen sulfide releases reported by th e facility. The facili ty calculates the hydrogen sulfide releases using published emission factors; the r eported releases were not a re sult of direct sampling (Schulz, 2014).

These facility contacts indicate that the majority of faciliti es reporting direct releases of hydrogen sulfide to TRI are calcu lating their hydrogen sulfide releases based on direct sampling at the facilities, and that facili ties are collecting the sampl es from onsite wastewater treatment systems. These facility contacts also suggest that direct relea ses of hydrogen sulfide reported to TRI accurately represent potentia l releases directly to receivi ng waters.

EAD further investigated dire ct releases of hydrogen sulfide re ported to TRI in 2013 as part of the 2015 Annual Review for the Grain Mills, Meat and Po ultry, and Pulp and Paper Point Source Categories. See Sections 3.3, 3.6, and 3.11 of the 2015 Annual Review Report, respectively, for more inform ation on EAD’s review. EAD did not further investigate direct hydrogen sulfide releases repor ting to TRI in 2013 for the Petr oleum Refining Category because EAD is currently conducting a d etailed study of the industry.

1.5 Hydrogen Sulfide Data Reported b y Facilities with Indirect Rele ases

As shown in Table 3, only 15 percent of the facilities reportin g water releases of hydrogen sulfide are indirectly di scharging to POTWs. However, these facilities account for approximately 50 percent of hydrogen s ulfide water releases rep orted to TRI. As a first step in assessing the quality of the hydr ogen sulfide data reported by the indirect discharging facilities to TRI and its utility for the 2015 Annual Review, EAD evaluated w hether the reported releases
downloaded from the DMR Pollutant Loading Tool for the TRA take into account any treatment and removal that is likely to o ccur at the receiving POTW.

As discussed in Section 3.4 of Technical Users Background Document for the Discharge Monitoring Report (DMR) Pollutant Loading Tool (U.S. EPA, 2012)

, the DMR Loading Tool adjusts, if possible, the TRI pollutant releases reported by in direct discharging facilities to account for pollutant removal that occurs at POTWs prior to rel ease to receiving waters. Table C-1 in Appendix C of the Technical Users Background Document for the Discharge Monitoring Report (DMR) Pollutant Loading Tool lists the POTW removals used for the TRI chemicals reported as transferred to POTWs (U.S. EPA, 2012). The adjusted releases are incorporated intoMemorandum October 29, 2015 Page 7

the industrial ranki ngs presented in the DMR Loading Tool that EAD then downloads to form
the basis for its TRA.

EAD reviewed the POTW pollutantremovals in Table C-1 in Append ix C of the Technical Users Background Document for the Discharge Monitoring Report (DMR) Pollutant Loading Tool and did not identify a removal specific to hydrogen sulfide. A ccordingly, the 2013 TRI hydrogen sulfide data for indi rect dischargi ng facilities d ownloaded from the DMR Loading
Tool do not account for treatment occurring at POTWs. Because h ydrogen sulfide in water readily oxidizes to sulfates and i s biologically oxidized to el emental sulfur under low to neutral pH and well aerated conditions, hydrogen sulfide removal rates at POTWs are lik ely significant, which would greatly reduce ultimate releases to receiving water s. Therefore, EAD determined it was necessary to identify a remova l efficiency that it could ap ply to the indirectly released hydrogen sulfide data reported in TRI, to account for hydrogen sulfide removed at POTWs.

To determine a removal efficiency that EAD could apply to the r eported releases of hydrogen sulfide from indirect di scharging facilities to accoun t for removal at POTWs, EAD 1) evaluated updates to the data s ources that form the current bas is for the POTW removals EAD uses in its annual reviews, and 2) contacted POTWs that are rec eiving wastewaters from the industrial facilities reporti ng the releases of hydrogen sulfid e to TRI. The results of these
evaluations are discussed in the subsections below.

1.5.1 Data Sources for Current POTW Removals

EAD reviewed the data sources tha t it has historically used to develop POTW removals as a starting point to determi ne a removal rate for hydrogen su lfide. These data sources include EPA’s National Risk Management Research Laboratory (NRMRL) Trea tability Database (U.S. EPA, 2004), EPA’s “50 POTW Study” (U.S. EPA, 1982), and POTW re movals incorporated
into EPA’s Office of Polluti on Prevention and Toxic’s (OPPT) Ri sk Screening Environmental Indicators (RSEI) model. EAD re lies on the RSEI model for POTW removals only in the absence of actual performance data. EAD most recently updated t he POTW removal efficiencies
it uses in its annual reviews of effluent guidelines in 2005 (E RG, 2005). During this update, EAD incorporated the most recent POTW performance data develope d in support of promulgated ELGs as well as mor e recent data compiled in the NR MRL Treatability Database, Version 5.0. EAD did not identify a ny more recent updates to th e NRMRL Treatability Database, nor has EPA promulgated any more recent ELGs that reg ulate the release of hydrogen sulfide; therefore these data sources did not provide any new i nformation regarding POTW removals of hydrogen sulfide.

EAD also reviewed the RSEI mode l to determine if new data were available for the removal of hydrogen sulfide at POTWs. The RSEI model primarily relies on POTW removals
obtained from the NRMRL Treatab ility Database, but also relies on Syracuse Research Corporation’s (SRC’s) Sewage Tr eatment Plant Fugacity Model (ST PWIN) for those chemicals
not in the NRMRL Treatabilit y Database (U.S. EPA, 2013). EAD di d not identify any recent updates to the NRMRL Treatabilit y Database; therefore EAD inves tigated POTW removal rates for hydrogen sulfide that may be a vailable in the STPWIN model.Memorandum October 29, 2015 Page 8

EAD downloaded the latest versi on of SRC’s STPWIN model (U.S. E PA, 2013), which is integrated into EPA’s Estima tion Program Interface (EPI) Sui te 4 (EPI Suite Version 4.11 (November 2012)). The EPI Suite is a suite of physical/chemical property and environmental fate estimation programs developed by the EPA’s OPPT and SRC. The ST PWIN model in particular predicts the removal of chemi cals by typical activated sludge-b ased sewage treatment plants.
OPPT caveats that the EPI Suite i s a screening-le vel tool and s hould not be used if acceptable measured values are available. In addition, OPPT emphasizes the importance of understanding
the estimation methods and their appropriate application.

According to the general informa tion provided in the EPI Suite, the STPWIN model is based on fugacity principles and a ttempts to predict the fate o f chemicals in an “evaluative environment.” In this case, the e valuative environment is a co nventional wastewater treatment plant that uses activated sludge secondary treatment. The mode l estimates the fate of chemicals present in the influent as t hey are removed by evaporation, bio degradation or other degradation processes, sorption to sludge, a nd loss in the final effluent. The most critical and uncertain variable is the biodegradati on rate and its dependence on bioma ss concentration.

This model is useful for establis hing the general features of achemical's behavior in an activated sludge sewag e treatment plant. I t is not intended to provide an accurate simulation of chemical fate in a specific plan t. Rather, it is a screening-l evel model that seeks to provide rough estimates of the proportions of the chemical likely to leave th e system by biodegradation or other degradation processes, in sl udge, by evaporation, and in the wa ter outflow. These proportions are dictated by both the propertie s of the substance and the ch aracteristics of the treatment plant.
STPWIN uses a combination of defa ult parameters and input param eters that may be user defined or estimated by other programs within EPI Suite.

The STPWIN model uses the following default POTW system propert ies (EPI Suite Version 4.11 (November 2012)):

Table 5. STWPIN Model Default POTW System Properties

Parameter a Tank 1 (primary) Tank 2 (aeration) Tank 3 (settling)
Tank area (m 2 ) 266.7 800 727.3

Tank depth (m) 3.8 10 3.8

VSS concentration (g/m 3 ) 50,000 -- 5,500

VSS biomass (fraction) 0.005 0.0025 0.00055

Outflow MLVSS concentration (g/m 3 ) 80.2 2500 15

VSS aeration rate (m 3 /hr) -- 8960 --

Fraction of influent fl ow recycled -- -- 0.8

4 For more information on EPI and to download the model see: htt p://www.epa.gov/oppt/exposure/pubs/episuite.htmMemorandum October 29, 2015 Page 9

Table 5. STWPIN Model Default POTW System Properties

Parameter a Tank 1 (primary) Tank 2 (aeration) Tank 3 (settling)

Fraction of influent flow removed 0.0024 -- 0.015

VSS−volatile suspended solids MLVSS−mixed liquor volatile suspended solids

a Other system properties: inf luent total flow = 1,000 m 3 /hr; influent volatile suspended solids concentration = 200 g/m 3 ; gas phase mass transfer coeffi cient = 5 m/hr; liquid phase ma ss transfer coefficient = 0.05 m.

The model requires input values for vapor pressure, water solu bility, and log K ow . These can be entered by the user or es timated by other models in the EPI Suite. The tool also contains a database of chemical properties (PHYSPROP database) that can be imported. For the purpose of running the model, EAD used the P HYSPROP database to provide th e default chemical property data for hydrogen sulfide. These va lues are shown in Table 6 an d are consistent with the values
identified in Table 1.

Table 6. PHYSPROP Database Chemi cal Properties for Hydrogen Sul fide

Property PHYSPROP Database Value Melting Point -85.49 o C Boiling Point -60.33 o C Water Solubility 3,740 mg/L at 21oC Vapor Pressure 15,600 mm Hg at 25oC LogK ow --

The model also allows the user to vary the assumptions for the degradation half-life of the chemical. There are three opt ions available, as indicated b elow (Option 1 is the default):

 Option 1: 10,000 hours for the prim ary clarifier, aeration vess el and settling tank.
These values are used to si gnify no biodegradation, normally co nsidered a worst case
scenario.

 Option 2: Estimates based on BIOWIN 5 output. Half-lives are assigned based upon an EPA method using BIOWIN output.

 Option 3: User-entered values. The user enters the half-lives f or the primary clarifier, aeration vessel and settling ta nk. Documentation available for the model includes the following guidance for selecting ha lf-lives for conventional ac tivated sludge treatment: for rapid biodegrad ation use 1 hour; for moderate us e 3 hours; for
moderate-to-slow use 10 hour s; for slow use 30 hours.

5 BIOWIN estimates aerobic and an aerobic biodegradability of org anic chemicals using a combination of techniques.Memorandum October 29, 2015 Page 10

To calculate a hydrogen sulfide PO TW removal using the STWPIN m odel, EAD entered the chemical properties for hydr ogen sulfide shown in Table 6 a nd used the default option (option 1) for the degradati on half-life of hydrogen sulfide, w hich provides a conservative removal rate. The resulting POT W removal calculated by the STWP IN model for hydrogen sulfide is 98.64 percent.

1.5.2 Data Collected from POTWs Receiving Hydr ogen Sulfide Releases from Industrial
Facilities

As part of the review of hydroge n sulfide releases in TRI, EAD contacted one POTW that
receives wastewaters f rom industrial facili ties reporting relea ses of hydrogen sulfide to TRI, and one POTW reporting hydrogen sulfi de discharges on its DMR, list ed below.

 Lafayette Wastewater Treatment Plant in Lafayette, IN; and

 City of Tolleson Wastewater Treatment Plant, Tolleson, AZ.

The Lafayette Wastewater Treatm ent Plant did not have any treat ment data for hydrogen
sulfide and was not concerned a bout hydrogen sulfide loads rece ived from industr ial facilities (Beeler, 2014). The City of Tolles on Wastewater Treatment Plant provided 2013 and 2014 hydrogen sulfide treatment data: raw influent hydrogen sulfide concentrations range from 0.23 – 0.742 mg/L, and the treated efflue nt concentrations are 0.01 mg /L or less (Tyler, 2014). These data present a hydrogen sulfide per cent removal at the POTW ran ging from 95.7 to 98.7. These data suggest that the estimate d removal rate of 98.64 percent f or hydrogen sulfide at a POTW
obtained from the STPWIN model is reasonable for EAD’s use in a djusting the indi rect releases of hydrogen sulfide reported to TRI.

1.6 Hydrogen Sulfide POTW Removal Adjustment

After reviewing available data r egarding POTW removals of hydro gen sulfide and contacting several POTWs that ar e receiving wastewaters from th e industrial facilities reporting the releases of hydrogen sulfide to TRI, EAD determined that it was appropriate to incorporate into the 2015 TRA a POTW percen t removal for hydrogen sulfide o f 98.64 percent for indirect releases of hydrogen sulfide rep orted to TRI. EAD derived this removal from an underlying model (STPWIN) that OPPT uses in its RSEI model to estimate POT W removals of TRI chemicals. EAD has historically relied on RSEI as a data source for POTW removals in the absence of actual performance da ta from EPA/ORD’s NRMRL Treatab ility database or the 50 POTW Study. Further, the underlyi ng assumptions EAD entered int o the STPWIN model provide a conservative estimat e of the removal of hydrogen sulf ide from a POTW and are consistent with removals achieved by at least one POTW treating indirect releases of hydrogen sulfide from facilities reporti ng to TRI. Table B-1 in Appendix B of the 2015 Annual Review Report (U.S. EPA, 2016)

, lists the facilities with indi rect hydrogen sulfide releases, adjusted to
account for POTW removals. EAD us ed these adjusted values to de velop the final 2015 point source category rankings fo r the TRA, supporting the 2015 Annua l Review.Memorandum October 29, 2015 Page 11

1.7 References

1. ATSDR. 2014. U.S. Department of H ealth and Human Services, Agen cy for Toxic Substances and Disease Registry. Draft Toxicological Profile for Hydrogen Sulfide and Carbonyl Sulfide . Atlanta, GA. (October). Available online at: http://www.atsdr.cdc .gov/ToxProfiles/tp114.pdf . EPA-HQ-OW-2015-0665. DCN 08125.

2. Beeler, Brian. 2014. Telephone and Em ail Communication with Bri an Beeler, Lafayette WWTP, and Kimberly Bartell, Eas tern Research Group, Inc., Re: 2 013 Hydrogen Sulfide Discharges at POTWs. (Decembe r 19). EPA-HQ-OW-2015-0665. DCN 08 217.

3. Dirks, Kim. 2014. Telephone and Ema il Communication with Kim Di rks, Tyson Fresh Meats, and Kimberly Bartell, E astern Research Group, Inc., Re: 2013 TRI Hydrogen Sulfide Discharges for Tyson Fre sh Meats in Hillsdale, IL. (Jan uary 8). EPA-HQ-OW2015-0665. DCN 08220.

4. ERG. 2005. Memorandum to the 2006 E ffluent Guidelines Program P lan Docket, EPA Docket Number OW-2004-0032, from Ellie Codding and Deb Bartram, Eastern Research Group, Inc., Re: Publicly Owned Tr eatment Works (POTW) Percent Removals Used for the TRIReleases2002 Database. (August 12). EPA-HQ-OW-2004-0032- 0967.

5. Razink, Jonathan. 2014. Telephone a nd Email Communication with Jonathan Razink, Cargill, Inc., and Kimberly Bar tell, Eastern Research Group, In c., Re: 2013 TRI Hydrogen Sulfide Discharges for Cargill Inc., in Wahpeton, ND. (December 22). EPAHQ-OW-2015-0665. DCN 08127.

6. Schulz, Charles. 2014. Telephone a nd Email Communication with C harles Schulz, John Morrell and Co., and Kimberly Bar tell, Eastern Research Group, Inc., Re: 2013 TRI Hydrogen Sulfide Discharges fo r John Morrell and Co. (December 22). EPA-HQ-OW2015-0665. DCN 08158.

7. Schwartz, Jerry, and Paul Wiegand. 2014. Telephone and Email Co mmunication between Jerry Schwartz, American Forest and Paper Association, Paul Wie gand, National Council for Air and Stream Improvement, a nd Kimberly Bartell, Eastern R esearch Group, Inc., Re: 2013 DMR and TRI Pulp and Paper Discharges. (December). EPA -HQ-OW-2015-
0665. DCN 08201.

8. Tyler, David. 2014. Telephone and E mail Communication with Davi d Tyler, Tolleson WWTP, and Kimberly Bartell, Eas tern Research Group, Inc., Re: 2 013 Hydrogen Sulfide Discharges at POTWs. (Decembe r 19). EPA-HQ-OW-2015-0665. DCN 08 229.

9. U.S. EPA. 1982. Fate of Priority Pollutants in Publicly Owned Treatment Works (EPA 440/1-82/303). Washington, D.C. ( September). EPA-HQ-OW-2004-003 2-2097.Memorandum October 29, 2015 Page 12

10. U.S. EPA. 1986. Quality Criteria for Water . Washington, D.C. (May). EPA-HQ-OW2004-0032-2619.

11. U.S. EPA. 2003. Toxicological Review of Hydrogen Sulfide . Washington, D.C. (June). EPA-HQ-OW-2015-0665. DCN 08276.

12. U.S. EPA. 2004. Office of R esearch and Development. NRMRL Treatability Data Base,

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