# HILL ENGINEERING, INC. 8 CIBSON STREET NORTH EAST, PENNSYLVANIA 16428 (814) 725-8659 FAX: (814) 725-3867

Mt:. Stephen G. Copeland Office of Municipal Assistance (3WP41 ) U. S. Environmental Protection Agency 1650 r \ rch Street Philadelphia, PA 19103 -2029 

### RE,-,.....··**~-** 

### EPP**.January 9.,2()1~**  

### E
. II/



### " I' NPDtS 

### t, ., (3\
.. "1 

### NPDE:S ,CH
, 

## ,

Reference: Local Limits Analysis for Ridgway Borough N PDES No. PA0023213 Ridgway Borough Elk County, Penn sy lvania Dear Nlr. Copeland: '1

!inclosed is the Ridgway Borough Local Limits Analysis for yo ur review and approval, for the Ridgway Borough Pretreatment Program. It is currently the intent of the Borough to implement the results of this analysis on a load allocation ba sis, once the results of the model are approved. If you have any questions or comments, plea se call me.

E ncloSLu :es
cc: Dave Balog, PA DEP (w/e nclo sure) Paul McCurdy (w i enclo sure) Sincerel y,

# ~~'NC Richard B. Dodds

### RIDGWAY BOROUGH ELK COUNTY, PENNSYLVANIA NPDES PERMIT NO. PA0023213 PRETREATMENT PROGRAM LOCAL LIMITS

PREPARED BY: HILL 

### ENGINEERING, INC. 8 GIBSON STREET NORTH EAST, PA 16428 JANUARY 2014

### RIDGWAY BOROUGH LOCAL LIMITS TABLE OF CONTENTS SECTION NO. I. Treatment Plant Description 

### II
. NPDES Permit Effluent Limits 

### III. Regulated Pollutants IV
. Sampling and Data Collection V
. Model Parameters VI. Sludge Disposal VII. Local Limits Summary 

### VIII. Proposed Allocation Methodology 

### APPENDICES Appendix A Appendix A"I

- EPA Excel Spreadsheet ofPOTW Monitoring Data Appendix A"2

- POTW Influent Sampling Data Appendix A "3

- POTW Effluent Sampling Data Appendix A-4

- Domestic Wastewater Quality Sampling Data Appendix B EPA Local Limits Calculation Spreadsheet 

### PAGE 1 1 2 2 2 

### 3 4 4

### LOCAL LIMITS SAMPLING PLAN NPDES PERMIT NO. 

### PA 0023213 RIDGWAY BOROUGH 

### ELK COUNTY, PA
I. Treatment Plant Description Ridgway Borough owns and operates a sewage treatment plant and collection system in Ridgway Borough, Elk County, PA. The Ridgway Borough Treatment Plant (RBTP) also serves portions of Ridgway Township
. The treatment plant has a hydraulic design rate of 2
.2 MGD as a maximum monthly average. The plant discharges to the Clarion River under PA Department of Environmental Protection (PA DEP) NPDES Permit No
. PA0023213. The major components at the treatment plant consist ofthe following : Barscreen, Grit Chamber, Equalization Tank, Aeration Tanks, Clarifiers , Chlorination Feed System, Chlorine Contact Tank, Aerobic Digesters , and Belt Filter Press. 

### II. NPDES Permit Limits The Borough' s NPDES Permit No
. PA 0023213 contains the f ollowing effluent limitations : Concentration (mglL) Monthly Parameter Mass Loading (lbs/day) Monthly Average Minimum Average Maximum CBOD 

### s TSS NH3-N pH (s.u.) Fecal Coliform (5 / 1-9/30) (I 0/ 1-4/30) Fluoride Copper Total Dissolved Solids Total Chlorine 460 550 1,945

2,035

1.65 76 ,299 6.0 25 30 108
200 2,000 0.09 0.5 50 60 216 9.0 1,000 10,000 0
. 18

1.6 The permitted flow capacity ofthe treatment plants is 2
.2 MGD. The flow rate for local limits analysis was 1
.04 MGD based on the average annual flow rate for the 2007 through 2011 period.

I

### III. Regulated Pollutants Guidelines from EPA recommend regulating the following pollutants l : Arsenic Lead Cyanide Cadmium Mercury Selenium Chromium Nickel Hex. Chromium2 Copper Silver Zinc
The Borough intends to also regulate the following pollutants where its NPDES Permit also contains numerical limits: CBOD s Ammonia Total Dissolved S olids Fluoride Total Suspended Solids
In addition, the Borough also included the following pollutants into the Local Limits analysis , but they may not require regulation 3 : Chloride Barium


### IV. SIGNIFICANT INDUSTRIAL USERS Sulfate

Based on the reported information for four (4) ofthe SIUs tributary to the Borough 's wastewater treatment facility NPDES application, their process discharge quantity is : Permittee Allegheny Coatings Metal Powder Coatings Diversified Coatings Ion Technologies 

### gpd 618 35 256 843

I The Borough does not intend to monitor or regulate molybdenum through the EPA Pretreatment Program since the basi s for its control is limited to the Clean Sludge requirements associated with the land application ofbio solids
. Without land application requirements, the development of Local Limits for molybdenum is unnecessary since there are no federal or state discharge limits for this contaminant, nor are there inhibition values a ssociated with this rarameter.

PLEASE NOTE : Since virtually all the levels ofTotal Chromium were significantly lower than the LOD (50 ppb) available for Hexavalent Chromium, data for Total Chromium were used in replacement for Hexavalent Chromium values throughout the entire analysis . 3 As stated in the approved Local Limits Monitoring Plan , the Borough is not including pollutants such as strontium, bromide , or specific radionuclides in this analysis since there are no known sOurces ofthese parameters in general domestic wastewater (the offset source ofthe analysis). In addition , there are also no inhibition value s for these parameters in the published EPA guidance
. 2In addition, there is a fifth SIU, Alpha Sintered Metals, Inc., which has an approximate annual average industrial discharge quantity of 31 gpd. Also, based on the 2011 Annual Pretreatment Report, the treatment facility receives approximately 1,860 gpd for hauled in wastes from Chattanooga Labeling Company, 309 gpd of wastewater from GKN Sintered Metals, 508 gpd of municipal wastewater sludge , 870 gpd of septage, and an average of 13,589 gpd ofhauled in gas industry brine waste.


### V. Sampling and Data Collection The Borough collected samples for ten (10) consecutive days at the following locations: POTW Influent POTW Effluent Domestic Sample Location The results ofthese samples were used, along with the results ofprevious influent and effluent sampling results from quarterly monitoring results from 2012 and part of20 13 , to calculate removal rates4 • The samples for all pollutants was 24-hour composites, except cyanide which was four (4) grab samples over a 24-hour period. The sampling for POTW Influent and Effluent was 24-hour flow proportional. The domestic sampling in the sewer system was 24-hour time proportional as proposed in the approved sampling plan. An additional ten (10) sampling days were collected from the same domestic wastewater sampling location, on non-consecutive days, for a total of twenty (20) sampling events.


### VI. Model Parameters A. Model Inputs. Based on the 2011-12 flow monitoring data, the Borough's plant has an average flow of 1.04 mgd. Approximately 0.020 mgd of the flow is attributable to tributary industrial facilities, as discussed in Section IV ofthis documents. The results ofthe sampling for influent, effluent and domestic wastewater, were included in the spreadsheet under the "Monitoring Data" worksheet. B. Water Oualitv Criteria

4 The 2011 data set was not utilized due to significant differences in detection levels and changes in influent sampling points that resulted in substantial differences in influent data characteristics.

, Since hauled-in waste was not sampled separately, but were included in the influent sampling, the total flow from these sources were included into the existing industrial sources . 3Ridgway Borough's NPDES permit limits were included in the spreadsheet model for CBOD , TSS, TDS , arrunonia-N, copper, and fluoride 6 

### In addition, human health criteria values were also included. Since the DEP evaluated the discharge limits for the NPDES permit based on the states chronic and acute water quality criteria, these values were not include into the model. Chapter 93 instream concentration water quality limits for chloride and sulfate were assessed in Table 4 ofthe spreadsheet7• C. Removal Rates Removal rates for the following parameters were based on actual data collected during this survey: Cadmium Lead Zinc TSS Chromium Nickel Ammonia Barium Copper Silver CBOD
The removal rates for the above listed parameters are listed in Table 3 of the EPA ' s spreadsheet. Standard removal rates for activated sludge wastewater treatment facilities were assumed for the following parameters: Arsenic Chromium (VI) Cyanide Selenium Mercury
In the event that there was no apparent removal rates shown during the survey and no standard removal rates reported in EPA guidance, no (zero) removal percentage was assumed. Specifically, zero (0) percent removal was assumed for: Chloride TDS Sulfate Flouride
Based on Option 1, in Table 5-1 ofthe manual, all data that was below the level of detection was considered to be of 

### y, the value of the level ofdetection. The values for primary removal efficiencies (Rprim) used in Table 8 ofthe accompanying EPA Local Limits spreadsheet were the median values for each respective parameter reported in the table entitled "Priority Pollutant Removal Efficiencies (%) Through Primary Treatment" on page R-I ofthe EPA's "Local Limits Development Guidance" manual
.

6 Although there is no concentration limit for fluoride, ammonia-N, or TDS, a concentration value was derived by dividing the respective monthly mass load limit by the 1
.04 mgd average flow.

, Table 4 ofthe EPA spreadsheet was used for the Chapter 93 evaluation since it is based on Q , .IO flows. 4D. Inhibition Values The inhibition values for activated sludge were assumed to be the median values listed in the EPA Guidance Manual
. Inhibition values are shown on Table 8.


### VII. Sludge Disposal Ridgway Borough currently disposes of all of its sludge through landfill disposal. Since Ridgway Borough does not currently utilize land application of sludge and continues to have no interest in instituting the land application program, sludge disposal land application has not been considered as a factor in determining local limits. As such, the land application ceiling and cumulative application rates from 40 CFR Part 503.13 were not used in determining the local limits reported in this document.


### VIII. Local Limits Summary The local limits were determined using the EPA computer spreadsheet model on Excel available for download during 2013
. The local limit utilized was the most restrictive of the values calculated based on NPDES Permit, human health criteria, and activated sludge inhibition. Safety and expansion factors of 10% were assumed for all pollutants , with the exception ofTSS, ammonia, CBOD j , and TDS , which were assumed at 5%. Allowable growth rates of 5 percent were assumed for all parameters. The proposed "Allowable Industrial Loading(s)" are summarized in Table 15 ofthe printout ofthe EPA Excel spreadsheet.


### IX. Proposed Allocation Methodology The local limits will be allocated to industrial users in accordance with EPA guidelines. Currently, the Borough ' s local limits are allocated based on the mass proportional method whereby the allowable loadipg is allocated to the existing users based on current loadings. As is currently the case, the mass proportional method of allocation will be subject to existing or future agreements with industries regarding capacity utilization of the POTW. Local limits will be superseded ifcategorical limits are more stringent.



### 5

### , POTWName: 11812014 POTW Monitoring Data

CIlia points .v..-g. by
_ tIwIn 2 11_ lIMo ttandolrd IMvllltion lor 1h8i POIhlUlnl Md umpM pol",
. 

# 7

1 0111 tl'A"-
.....____ U
.

# i 

# i I I 

### j i



## • NPOTW Name : 111!12014 POTW Monitoring Data

# ~r.

3 0 111**"- C-**  ___ Y_" O

# ~**~**

!!**~** c c
·c 

### .ll c 0 

# '"**~** 0 

# ..**~ ~**  

# fY\

J J

# ~**"-~~ ~\b**  i 

# I I J 

# i !

= 

## • 

# .POlWName : 11&'201. POTW Monitoring Data

# ~ ;JE'r.

SOl 11**E'~"""~'_""~_'"**

# i 

# I ! J 

# i !POTW Name: 1/81201. POTW Mon itoring Data



# ) /

70111**"._~""** __ _ V _' -O

# j 

# I ! I 

# i !



### - 

## • 

# .

# .

r

## ~

# ~ 

# 'CJ

1\

# Wd.H-I~~ mtttttt+l+w+W-

# WJ

# ~ i 

# I I i !



### - ,; 

# .

# r**~** c 

### ' 2 0 

## '"**~** 0 :;;

## ~ 0..



# • __ Jilllll l",**~ ~**  

## II

# ~**~** 

# I I 1 

# i !



## • 0

# i 

# I ! 1 

# i i