Appendix 4-29 Technical Memorandum WW-1 on Existing WWTF and Vent Evaluation

Appendix 4-29 Technical Memorandum WW-1 on Existing WWTF and Vent Evaluation

TECHNICAL MEMORANDUM WW-1

March 8, 2013

To Town of Falmouth, MA

Copy to File; Project Team

From Marc R. Drainville PE, BCEE, LEED AP Tel 774-470-1634 J. Jefferson Gregg, PE, BCEE 774-470-1640 Wastewater and Nutrient Management Services Subject Job No. 8615097 Existing WWTF and Vent Evaluation

1 INTRODUCTION The purpose of the memo is to evaluate the existing Falmouth Wastewater Treatment Facility and service vent in order to determine the treatment capacity of the facility and also identify operational limitations. The evaluation consists of the following tasks: x An assessment of treatment capacity and capacity limitations on all unit processes. x An assessment of the equipment and structures at the facility determining the physical state of the equipment and structures. x A detailed assessment of all processes and groups of equipment to compare them to current standards. x A review of plant operations.

The facility was evaluated against the following design standard: x TR-16 Guides for the Design of Wastewater Treatment Works; New England Interstate Water Pollution Control Commission, 2011 Edition. This document was used because it is a New England design standard and is comprised of industry standard documents such as NFPA 820 and Water Environment Federation (WEF) Manual of Practice textbooks. This is the document that DEP uses in its approval process for new and modified wastewater infrastructure. It should be noted that an earlier version of the document would have been used to design this facility. The current version was used in this evaluation as a reference document because any updates made to the facility will need to comply with the most current version available.

2 BACKGROUND The Falmouth Wastewater Treatment Facility was originally constructed in 1986. At that time, the facility consisted mainly of a lagoon treatment system, and had a single process and control building. Effluent disposal was accomplished by open sand beds and spray irrigation. In 2005, the main treatment process of the facility was changed from lagoon treatment to Sequencing Batch Reactors (SBR) followed by denitrification filters. This facility’s design targets were an effluent Biochemical Oxygen Demand (BOD) of 30 mg/L and an annual average effluent Total Nitrogen (TN) of 3 mg/L, based on the influent load conditions in the performance guarantee for the SBR.

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In 2011, a new groundwater discharge permit was issued to the Town. Both the Town and the Buzzards Bay Coalition appealed this permit, which, among other restrictions, included an average annual total nitrogen effluent limit of 3.0 mg/L. The appeal was settled and the final permit took effect June 29, 2012. The final permit is shown in Appendix WW-1-A. It should be noted that this memo reviews the ability of the existing facilities to treat additional flow (as stated in Section 1 above) on a hydraulic and treatment capacity only. The current permit significantly restricts the flow of the facility below the design capacity of the plant to 800,000 gpd or less. The permit is the subject of a companion project. The scope of this work is as defined in GHD’s proposal dated September 5, 2012.

3 FLOWS AND LOADS 3.1 Existing Flows and Loads This section will review historical data with respect to plant flows and loads, and comment on the approximate capacity of the facility. Over the years, operational changes have been made and process upsets have been minimized. As a result of this, and possibly other factors, performance within the past two years in particular has been very good. As a result, data will be presented both for the entire period the plant was in service as well as within the past two years. The performance of the facility over time is shown in the following tables. Table 3-1 shows the composite performance since the upgraded plant was put into service. The performance of the facility, in relationship to the permit in effect at the time, is the subject of the Nitrogen Optimization Plan (currently in development). Table 3-1 Effluent Concentrations January 2006—November 2012

Average (mg/L) Max 30 Day Avg (mg/L) Max Day (mg/L) Effluent BOD 3 51 91 Effluent TSS 3 34 38 Effluent TN 5 20 22 Effluent NO2 0 0 0 Effluent NO3 1 7 8 Effluent TKN 3 19 22

Plant operations have been fine-tuned over the years, and some operational changes have been made in recent years to enhance performance. As a result of a combination of factors, performance within the past two years has been very good as demonstrated in Table 3-2.

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Table 3-2 Effluent Concentrations November 2010—November 2012

Average (mg/L) Max 30 Day Avg (mg/L) Max Day (mg/L) Effluent BOD 2 15 58 Effluent TSS 3 7 9 Effluent TN 3 5 8 Effluent NO2 0 0 0 Effluent NO3 1 2 6 Effluent TKN 2 5 5

3.1.1 Existing Flows Table 3-3 summarizes the influent flows seen at the WWTF during the two-year period of November 2010 to November 2012. Flow measurement analysis at the Falmouth WWTF is summarized in the ‘Flow Measurement Evaluation’ compiled by GHD in 2012 (currently in draft form and under review by the Town). It should be noted that the intent of the Flow Measurement Evaluation is to improve flow measurement at the plant as the accuracy of some measurements have been questioned. Table 3-3 Influent Wet Well Measured Flows November 2010—November 2012

Average (mgd) Max 30 Day Avg (mgd) Max Day (mgd) Influent Wet Well 0.43 0.62 0.92

3.1.2 Existing Loads A summary of plant influent loads and concentrations are shown below in Tables 3-4 and 3-5. Table 3-4 Influent Concentrations January 2006—November 2012

Average (mg/L) Max 30 Day Avg (mg/L) Max Day (mg/L) Influent BOD 178 465 488 Influent TSS 186 895 895 Influent Ammonia 16 30 48 Influent TKN 28 56 89 Influent TN 29 56 89

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Table 3-5 Influent Loads January 2006—November 2012

Average (lb/d) Max 30 Day Avg (lb/d) Max Day (lb/d) Influent BOD 618 1717 2479 Influent TSS 643 2534 3914 Influent Ammonia 52 133 200 Influent TKN 89 218 332 Influent TN 89 218 332

These summaries of plant data will be examined more closely in Section 3.2 to help determine current capacities. The influent BOD Data from January 2006 to September 2012 is graphically presented in Figure 3-1.

Figure 3-1 Influent BOD (mg/L) vs. Time

As can be seen in Figure 3-1 the data set contains a measurement on 6/12/2008 of 1,007 mg/L, which is at least twice any other concentration seen during the data collection period. Because of this, the value was determined to be an outlier.

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Figure 3-2 shows the same data set without the outlier and also includes a trend line of the revised data set.

Figure 3-2 Influent BOD (mg/L) vs. Time

This figure shows a downward trend in the BOD concentration over time, and this decrease in the concentration has occurred while plant flows have remained steady (actually flows have increased slightly over this time period). Table 3-6 shows the clear decrease in the loading. Table 3-6 Influent Average Loading

Loading Since Startup (2006—2012) 2006—2010 Nov 2010—Nov 2012 Influent BOD (lb/d) 619 722 247

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3.1.3 Existing Capacity The Falmouth WWTF was designed to receive an average flow of 1.2 million gallons per day (mgd). The concentrations and loadings which the facility was designed for are detailed in the draft Falmouth WWTF Operations & Maintenance Manual (See Appendix WW-1-B). The data outlined in the previous section can be compared to the design loading conditions for the facility to determine if the SBR is adequately sized for its current operation. The process guarantee from AquaAerobics is included as Appendix WW-1-E. Because the current permit requires the facility to meet a monthly permit for all parameters, including nitrogen, existing maximum 30 day influent loading conditions were determined. Although it is understood that the current permit in Appendix WW-1-A does not have a true limit for Nitrogen, our analysis was based on the assumption that a future permit may contain a monthly limit of total nitrogen as low as 3 mg/L. As shown previously, influent BOD loads trended downward over the past several years. In order to account for this apparent load reduction, more recent data was considered. In addition, plant performance has been steady over the past two years and process upsets have been minimized. As a result of both of these factors, the past two years of plant data seemed to be representative of current conditions. Table 3-7 Design and November 2010 to September 2012 Loading for Sequencing Batch Reactors (lb/d)

Design Loading (stated as SBR Design “average” in Loading Influent performance Max 30 Day Avg Capacity Concentration guarantee) Loading Currently Used BOD5 250 2502 1372 55% TSS 180 1801.4 1259 70% TKN 30 300.2 218 73% Total N 36 360.3 218 61%

From this analysis, it would appear that the facility is at approximately 60-70% capacity.

3.1.4 Recycle Loads Because of the location of the influent sampler, composite influent wet well samples do not include recycle flows even though the recycle flows enter the wet well. When recycle flows are introduced into the influent wet well, the facility takes a grab sample of the pump discharge to record the concentrations of BOD, TKN, ammonia, and TSS. In order to estimate whether recycle loads are adequately represented in the data, maximum 30 day concentration days for influent nitrogen and BOD were reviewed. During maximum 30 day conditions, grab recycle flow sample concentrations for both BOD and TKN were much lower than the respective composite sample in the wet well. This would indicate that recycle flows do not substantially increase loading to the

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SBRs during maximum 30 day conditions. However, under average conditions, influent concentrations did appear to be influenced by recycle loads. More consistent data is needed to verify this conclusion. It is suggested that the facility obtain grab samples at the influent wet well when also taking grab samples of the recycle flow in order to obtain a true comparison between the two concentrations.

3.2 Future Flows and Loads The flows shown in Table 3-8 are based on the current recorded average and maximum day flows, and the predicted future flow increase of 320,000 gpd—which includes infiltration and inflow—that is estimated to be from the Lower Little Pond Sewer Extension Area. The predicted maximum day and peak hour flows are based on TR-16. Table 3-8 Current and Future Plant Flows

Current Added Total Future Falmouth WWTF Flows Flow Flow Design Flows Average 0.36 0.32(2) 0.68(3) 1.2 Maximum Day 0.67 0.59(1) 1.26 2.2 Peak Hour 1.22(1) 1.08(1) 2.3 4.3 Notes: 1 Memo S-3 Peaking Factors 2 See Memo S-3 3 Sum of current and estimated additional flows

Based on the table above, the new plant flows will be less than the design flows shown on Sheet G-9 of the ‘Town of Falmouth Wastewater Treatment Facility Improvements’ drawings dated February 2003 and developed by the Maguire Group. A new hydraulic profile was not developed, but based on the hydraulic capacity given in the design drawings, the facility will still be below capacity on a hydraulic basis. It should also be noted that the future average total flow is less than the average annual flow in the current permit – 800,000 gpd. Even though the facility may be hydraulically capable of treating the new flow, the facility also needs to be examined for its ability to treat future loads. In order to determine future loads to the facility, the existing maximum 30-day loads from the last section were used to represent existing conditions. The future loads were determined based on the following. The future sewer service area was estimated in Memorandum S-3 to contribute 284,000 gallons per day of wastewater on an average basis. In reviewing the makeup of this area, it was noted that the majority of the area is residential. A small portion of the area was estimated to have a makeup similar to the existing plant influent (commercial) while the majority of the additional flow was estimated to be residential. For the residential area, the population was estimated and per capita loadings provided in TR-16 were used along with maximum month loading peaking factors. For the area that was estimated to be similar to the existing

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facility flows, the concentration of BOD, TSS, and nitrogen was estimated to be equal to the current maximum 30 day concentration. Table 3-9 Current and Future Plant Loads

Future Future “Average” Estimated Estimated Loadings Existing Load from New Load from New Contained in Maximum 30 Residential Commercial Future Performance Day Loads Area Area Loads Guarantee BOD5 1372 738 165 2275 2502 (lb/d) TSS (lb/d) 1259 897 318 2474 1801 Total N 218 171 20 409 360 (lb/d)

Because the overall loads are either close to or higher than those contained in the original SBR performance guarantee, GHD contacted AquaAerobics, the developer of the process model for the SBR, to determine the maximum capabilities of the current system to treat the future loads. According to AquaAerobics design summaries (See Appendix WW-1-C), the existing tanks and equipment are just able to treat the future flows and loads with little reserve capacity while maintaining the current effluent limits contained within the performance guarantee1. Since the design documents and performance guarantee both use the term “average” when referring to influent loads, it is not known exactly what maximum condition was used to size the tanks. It is our experience that manufacturers size tanks and equipment conservatively, especially when they provide a process guarantee as AquaAerobics did for the Town in 2005. Since the results of this analysis reveal that the existing tanks are capable of treating the future flows and loads contained in this memorandum, this conservatism is beneficial. The development of the original flows and loads and the decision to base the design of the SBRs on the loads contained in the performance guarantee were not investigated because it was not germane to the current goal, but it should be noted that with the currently planned future loads, the SBRs would be at capacity as they are currently constituted. Table 3-10 below gives a summary of the capabilities of the current system and estimates when future upgrades will be needed.

1 It should be noted that the plant has historically had issues with high effluent refractory nitrogen. The SBR will not remove refractory nitrogen and any issues that are currently present with respect to refractory TKN will continue. This topic is unrelated to the capacity evaluation, but will be covered in detail in a separate document related to Nitrogen Removal Optimization Planning.

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Table 3-10 SBR Capacity Evaluation

Increase loads by Increase loads up to 15% beyond 15% to 75% Existing Flows Future Flows those projected beyond those and Loads and Loads above projected above Condition Under capacity At capacity with Add additional Add an additional with existing existing tank diffusers and tank tank and and equipment associated equipment equipment

As stated in Section 3.1.4, the recycle loads at the facility do not seem to impact the loads to the SBR under maximum 30-day loading conditions. However, since additional testing has been recommended to confirm this conclusion, an allowance of an additional 10% load will be added to the maximum 30-day loads to account for some additional recycle load. An additional 10% load over the course of the day represents a significant load, but a reasonable one at a facility of this size. However, as will be discussed in Section 4, the only accommodation that will be needed will be additional diffusers (the current blowers have excess aeration capacity which can accommodate the additional diffusers). If the conclusion that recycle loads have a minimal impact on the maximum 30-day loads that have already been estimated can be verified, this 10% load is recommended to be removed from the analysis. Once the additional testing that was recommended above has been compiled, this evaluation should be updated to verify conclusions, If the true system capacity is desired, GHD can perform an independent check on the system using process modeling software. However, this would require additional testing and sampling and would not appear to be needed at this time because there is adequate capacity to handle the next phase of collection system expansion.

4 REVIEW AND/OR CONDITION ASSESSMENT

4.1 Introduction The following section is a process-by-process evaluation of the existing Falmouth WWTF. Existing equipment is documented, followed by a technical evaluation, a list of operational issues and recommendations for each process. Operational issues are based on conversations with the Town and facility operators as well as independent observations made during site visits on the following dates: October 19, 2012, October 26, 2012, November 2, 2012, and November 15, 2012. It is acknowledged that most of the facility is relatively new and thus it is expected that most process design standards are likely met by the facility. The focus of this evaluation will be on if the facility can take the additional flow and load defined in Section 3 and on any existing operational issues. If there is existing equipment that has exceeded its life expectancy, this will be noted. However, it should be noted that it is not the intent of this evaluation to provide recommendations to extend the life of the entire facility by 20 years. It is also not the intent of this evaluation to review all existing building systems against current standards, but if existing building systems are found to be non-functional in some manner, this will be noted in the evaluation.

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4.2 Service Road Force Main and Vent 4.2.1 Existing The Service Road Vent is located where the Jones Palmer Pumping Station Force main discharges to a gravity sewer upstream of the Falmouth WWTF. The manhole for this location has a vent in it with a passive carbon filter.

4.2.2 Evaluation The Service Road Force Main and Vent is reviewed in the Collection System Odor Control Evaluation Final Report compiled by Stearns & Wheler in February 2009 (see Appendix WW-1-D.)

4.2.3 Operational Issues No additional operational issues were noted.

4.2.4 Recommendations The ‘Collection System Odor Control Evaluation Final Report’ recommends construction of an in-ground biofilter, immediately adjacent to the discharge manhole, at the Service Road vent.

4.3 Preliminary Treatment 4.3.1 Existing The facility has an aerated grit chamber, which is currently bypassed. Influent is directed to the headworks screening channel, where flow is directed through a mechanical fine screen or a coarse bar rack bypass. Both pieces of equipment were placed into service in 2005. The mechanical fine screen is a Marck XV-Cw screw screen, supplied by Schloss Engineering with a ¼ inch bar spacing and a 35 degree angle of inclination. A bypass channel allows flow to be directed to a coarse bar rack if the fine screen is taken off-line. The coarse bar rack has 1¼ inch bar spacing and a 60 degree angle of inclination.

4.3.2 Evaluation The existing structure, and much of the equipment in this area of the plant, dates back to the original construction of the plant in 1986. Thus, most existing facilities that have not been replaced have exceeded their design life. The screen is the lone exception in that it was installed in the most recent upgrade. Based on the TR-16 recommendation that SBR’s be preceded by fine screens with a clear spacing of ¼ inch or smaller, the existing mechanical fine screen is sized adequately. In addition, the fine screen has a bypass in the event of a failure of the fine screen. With respect to the future flows of the facility, the screen was sized for a future flow that is higher than the projected future flows in Section 3 and thus should be adequate.

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4.3.3 Operational Issues No operational or other issues were noted.

4.3.4 Recommendations There are no recommendations for this area with respect to the ability of the facility to handle the additional flows and loads defined in Section 3 and no operational concerns were identified. However, it should be noted that the building has exceeded its design life and may require attention in the future. Although there are no specific recommendations for this area, it would be prudent to carry an allowance for future work in this area to update existing equipment if it will be expected to continue to be functional into the future (door replacement, etc). Table 4-1 Preliminary Treatment Recommendations

Issues Recommended Improvements It may be prudent to consider some basic updating for this facility at some point if it will be expected to continue to Facilities beyond their design life function well into the future, but no immediate concerns were raised so these are not current concerns. Any updating is a long-term consideration.

4.4 Influent Pumping 4.4.1 Existing From preliminary treatment, influent flows to one of two influent wet wells. The total tank volume of the two wet wells is 90,000 gallons. Either tank can be isolated by a sluice gate. The dry well contains four vertical constant speed centrifugal pumps which pump wastewater from the influent wet well to the SBR tanks. Pump data is summarized in the table below. The dry well also contains a set of duplex sump pumps, provided by Redlon & Johnson, with a pump capacity of up to 185 gpm at 38 total dynamic head (TDH) The sump pumps discharge into wet well #1. A magnetic flow meter is installed on the discharge force main from the influent wet well to measure flow to the SBRs. Table 4-2 Influent Wet Well Pump Information

Equipment No WWP-1 and WWP-2 WWP-3 and WWP-4 Number of Pumps 2 2 Manufacturer Flowserve Flowserve Model Worthington 4MF-9 Worthington 6MF-11 830 gpm 1,530 gpm, Capacity 1.2 mgd 2.2 mgd Pump Speed 1,770 rpm 1,770 rpm Motor Rating 15 hp 25 hp Motor Speed 1,800 rpm 1,800 rpm

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Equipment No WWP-1 and WWP-2 WWP-3 and WWP-4 Total Dynamic Head 35.2 ft 45.2 ft Suction Elbow Inlet Flange Size 6 in 8 in Pump Discharge Flange Size 4 in 6 in Year Placed Into Service 2005 2005 4.4.2 Evaluation With respect to the future flows of the facility, pumps were sized for a future flow that is higher than the projected future flows in Section 3 and thus capacities, with the largest pump off-line, should be adequate. TR-16 recommends that pumping station pumps are capable of passing at least a 3-inch diameter sphere which these pumps appear to be able to do.

4.4.3 Operational Issues In addition, the following issues were noted:

x The conduit inside the wet well has rusted due to the moist environment and sweating of conduit during temperature changes. x There is no ventilation in the influent dry well. The American Energy Exchange heat recovery unit in the influent dry well is no longer working x The plant’s alkalinity is about 120 mg/L which is fine, however, according to collected operational data, influent pH has dropped as low as 6.1. 4.4.4 Recommendations Based on the evaluation of the existing facility above and additional issues noted above, the following is recommended: Table 4-3 Influent Wet Well Recommendations

Issues Recommended Improvements Rusted Conduit Address rusted conduit. Ventilation Demolish the existing energy recovery unit and replace with ventilation fan. It is unlikely that an air recovery unit will pay for itself given the small volume of air. Low pH and adequate influent It is unusual to see a low pH and adequate alkalinity, but it is alkalinity likely that hydrogen sulfide is causing a change to the water chemistry. Accommodations for maintaining adequate alkalinity is recommended at the facility and the facilities are described in a later section.

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4.5 Sequencing Batch Reactors and Related Equipment 4.5.1 Existing Wastewater is pumped from the influent wet well into one of two AquaSBR Sequencing Batch Reactor (SBR) tanks. The total volume of both tanks is 0.884 million gallons. Sludge is wasted by gravity using a manual valve set at approximately 300 gpm and a pneumatic motor operated valve controlled by a timer. There is a flow meter on the sludge line. The system also has a waste activated sludge (WAS) pump. The SBR sequence goes through six steps:

1. Mixed Fill—True anoxic mixing, independent of aeration, with influent. Mixing is accomplished with a DDM-FSS Direct Driver Mixer/Blender. 2. React Fill—Aerated mixing with influent introduction into the tank. The tank is aerated through an Enduratube ER-2000 fine bubble diffuser system with a nominal operating airflow range of 2-28 square cubic feet per minute per duplex diffuser. 3. React—Aerated mixing under true batch conditions. 4. Settle—Solids/liquids separation. 5. Decant/Idle—Effluent withdrawal to the post-equalization tank through a mechanical floating-type gravity decanter. The decanter has a maximum decanting rate of 4,583 gpm. 6. Sludge Waste—Removal of excess biological sludge to sludge holding tanks. Oxygen is fed to the system through three SBR aeration blowers. Each blower is designed to provide process air over the range of 1,000 SCFM to 2,030 SCFM. Under normal operating conditions each tank has a dedicated blower with the third used as a standby unit. The SBR tanks are programmed to work in tandem so that one tank is always in a fill mode. During the decant mode the same amount of water that entered the tank during the mixed fill and react fill stage flows to the post-equalization tank.

4.5.2 Evaluation With respect to the future flows and loads for the facility, the existing tanks and equipment are adequately sized, as explained in Section 3. Thus no improvements are recommended related to these parameters. However, improvements will be required if loads increase beyond those defined in this report.

4.5.3 Operational Issues In addition, the following issues were noted: x Two diffuser assemblies cannot be removed from the SBR tanks.

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x If the facility were to have a spare mixer and decant mechanism it would minimize downtime in the event of a failure. Minimizing downtime will be critical with the permit requiring monthly effluent TN of 3 mg/L. x Very loud noise from air piping in blower room is heard within the SBR Building and at SBR tanks. This may be a result of the need for additional support or vibration isolation. x Based on NFPA 820, the entire SBR Building is a Class 1, Division 2, Group D area due to the sludge piping. Any new motors and electrical work would need to be explosion proof. x Cold weather operation during times of process upset has been noted to be a challenge. x Increased aeration capacity is needed in order to treat an additional accommodation being made for recycle loads as discussed in Section 3.

4.5.4 Recommendations Based on the evaluation of the existing facility above and additional issues noted above, the following is recommended: Table 4-4 SBR Recommendations

Issues Recommended Improvements Diffuser air assembly cannot be removed Repair or replace existing assemblies Air piping noise Investigate further and possibly reduce vibration through the use of additional supports and vibration isolation Spare equipment will reduce downtime in the event Purchase spare mixer and decant mechanism. of a failure Cold weather startup This topic will be addresses in more detail in the Nitrogen Removal Optimization Plan Increased aeration capacity needed to take in Install two additional diffuser racks in each existing additional flow SBR basin

4.6 Denitrification Filters and Related Equipment 4.6.1 Existing Flow is pumped by two 1650 gpm variable speed centrifugal Flowserve pumps from the post equalization tanks to three Severn Trent denitrification filters. The pumps are designed with 23 feet of total dynamic head (TDH). Denitrification filters are designed to remove nitrates through a fixed film biological process and to filter out suspended solids. Effluent flows through seven feet of media in the denitrification filters to a 36,000 gallon clearwell. Periodically two Flowserve 15 hp centrifugal backwash pumps pump treated wastewater from the clearwell to backwash the filter, releasing the solids that have collected in the tank. Each backwash pump has a 1,410

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gpm capacity with 27 feet TDH. Two Aerzen positive displacement blowers located in the blower room in the SBR building feed air to the denitrification filters for backwash. Each blower has a 1044 SCFM capacity at 14.5 psia and 100 degrees F. Effluent from the clearwell overflows into the UV disinfection channel.

4.6.2 Evaluation According to the design documents for the facility, the denitrification filters were designed to reduce nitrates from 8 mg/L to 1 mg/L. However, it should be noted that the SBRs were designed to treat total nitrogen down to levels of approximately 3 mg/L. Thus, this relegates the filters to mainly serve as polishing filters. The filters were designed for a peak hour hydraulic loading rate of 3.25 gpm/ft2 with one filter out of service. Since the hydraulic capacity exceeds the future projected flows, the hydraulic loading rate will not be exceeded with the additional flows discussed in Section 3. Supplemental carbon addition is a key element for successful denitrification. A system with both feed-forward and feedback capability is recommended for a system with total nitrogen limits less than 5 mg/L. Though the facility has the infrastructure for methanol addition supplemental carbon is currently not used in the denitrification filters.

4.6.3 Operational Issues In addition, the following issues were noted:

x The filter has not been operated as a denitrification filter nor has it been tested in the denitrification mode. x The analyzer assemblies are not the manufacturer’s standard and are not functional. x The seven foot drop into the filter leads to dissolved oxygen entrainment and would lead to increased methanol (carbon) consumption. x The denitrification filter weir collects algae and leads to oxygen entrainment. x The denitrification filter has no bypass for high flow events. x Methanol (carbon) addition occurs in an area with poor mixing

4.6.4 Recommendations Based on the evaluation of the existing facility above and additional issues noted above, the following is recommended:

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Table 4-5 Denitrification Filter Recommendations

Issues Recommended Improvements The filter has not been operated Develop a testing protocol and test the filter. This is planned to as a denitrification filter nor has it be done as part of the Nitrogen Removal Optimization Plan. been tested in the denitrification mode. The analyzer mechanism is not The analyzer mechanism should be replaced. the manufacturer’s standard, and is not functional. The seven foot drop in the Severn Trent has modified their design such that the discharge to the filter leads to installation of electric operated effluent valves and an dissolved oxygen entrainment ultrasonic level control are recommended for each filter in and increased methanol order to reduce the seven foot drop in the discharge. However consumption other alternatives exist and can be explored in the next phase of the project. The denitrification filter weir The weirs need to be cleaned regularly to reduce algae growth collects algae. when the filter is used as a denitrification filter. Cover the filters to reduce algae growth. The denitrification filter has no A bypass could be included by connecting the Denitrification bypass for high flow events. Filter influent pumps to the filter effluent piping. This would likely require DEP approval. Methanol (carbon) addition Coordinate with Severn Trent and determine best location to occurs in an area with poor add methanol (carbon) such as by injecting it into the filter feed mixing pump discharge piping.

4.7 Ultraviolet Disinfection 4.7.1 Existing Effluent flows from the clearwell into a Sunlight Systems UV disinfection system. Sunlight Systems LLC was bought by Siemens Water Technologies in 2007 and then Siemens dropped the product line in 2011. Parts for the system are now available from Donnellan UV. The UV system is made up of 48 UV lamps divided into two banks and is designed to treat an average flow of 1.2 mgd with a peak design flow of 1.83 mgd and peak future flow of 2.2 mgd. UV dosage, which is the rate at which energy is delivered to the system, is 36,048 microwatt 2 seconds per square centimeter (uWs/cm ) at 1.83 MGD and 36,000 uWs/cm2 at 2.2 MGD. The system can be upgraded from design flow to future flow, by expanding the channel width, for a peak future flow of 2.2 mgd. The system was designed with 100% redundancy, meaning either bank of lamps is capable of disinfecting the maximum daily flow.

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4.7.2 Evaluation Based on the future flows discussed in Section 3 the system is adequately sized in its current configuration. However the denitrification filter pumps, which have a pumping capacity of 1,650 gpm each, should have a portion of their upper range locked out so that they cannot pump at a higher rate than the UV disinfection system was designed to treat at. TR-16 recommends that the UV module and electrical equipment area is covered either with a weather- protective canopy or is enclosed within a building. The 2011 version of TR-16 also recommends a backup electrical supply capable of powering the entire system. The current system has an independent electrical supply to each system with no backup supply. Each bank has a Ballast Control Center (BCC) with a step down transformer from 480 volt to 230 volt. If the UV is upgraded in the future it is recommended that a backup electrical supply be provided, but this is not needed now. Based on conversations with the UV system manufacturer, it is understood that one of the UV banks is currently not in service and may require servicing to make it a fully redundant system.

4.7.3 Operational Issues In addition, the following issues were noted:

x A weather protective canopy should be installed to protect electrical equipment.

4.7.4 Recommendations Based on the evaluation of the existing facility above and additional issues noted above, the following is recommended: Table 4-6 Ultraviolet Disinfection Recommendations

Issues Recommended Improvements The system does not have Provide a weather protective canopy (this will require some weather protection relocation of existing electrical equipment) Redundant bank not fully Rehabilitate second bank. This will be accomplished with the operational. facilities operations and maintenance budget.

4.8 Effluent Distribution and Metering 4.8.1 Existing The effluent distribution and metering setup is described in the ‘Falmouth WWTF Flow Measurement Evaluation’ compiled by GHD in 2012 (currently under review by the Town).

4.8.2 Evaluation The effluent distribution and metering evaluation is included in the Flow Evaluation Memo mentioned above.

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4.8.3 Operational Issues In addition to items discussed in the Flow Evaluation Memo, the following issues were observed during site visits to the facility: x Flow meter readouts are all reading different units/measurements. They need to be adjusted or recalibrated. x Algae growth was observed in the effluent channel. x Stormwater that collects in the lagoons currently drains to the influent wet well and is treated by the facility, using up operational capacity. 4.8.4 Recommendations Based on the evaluation of the issues noted above, the following is recommended: Table 4-7 Effluent Distribution Recommendations

Issues Recommended Improvements Flow meter readouts all read These flow sensors are recommended for replacement in the different units Flow Evaluation memo Wet well should be covered to Aluminum covers can be installed over the effluent distribution control algae structure to control algae growth Lagoons should be drained to the It is understood the Town has prior permission from DEP to sand beds discharge Aeration Pond #3 stormwater that meets the permit directly to the sand beds without having to go through treatment at the facility. The facility has existing piping that could be utilized to direct the stormwater directly to the sand beds as long as the flow measurement modifications proposed in the Flow Evaluation Memo are implemented.

4.9 Septage Receiving 4.9.1 Existing The facility currently has four 20,000 gallon aerated septage receiving tanks. Because of the large amount of rocks introduced into the system from the many cesspools in the existing collection area, septage is emptied into the first tank allowing grit to settle before overflowing to the other three tanks. Operators can also pump septage to the influent headworks if necessary. A 425 gpm Septage Receiving Station by Lakeside was installed in 1998, but did not function well because of the rock content of the septage. A rock trap that was subsequently installed on the Receiving Station was too small to effectively capture the amount of rock introduced into the system. The tanks are cleaned every three months with a “Vac-Con” truck. The Town requests that septage haulers collect grease loads separately from septage loads, and discharge grease loads directly to the thickened sludge tanks. The grease is hauled off site, with the thickened sludge and not processed at the facility in order to prevent grease problems in the treatment system.

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4.9.2 Evaluation TR-16 recommends that a septage receiving facility have both coarse and fine screening capabilities in order to minimize wear on downstream equipment. The facility currently has a septage receiving station which is not in use.

4.9.3 Operational Issues In addition, the following issues were noted: x The first septage receiving tank is currently being used to trap rocks with overflow flowing to the other receiving tanks. The first tank is hard to access and clean. x Better monitoring of tank levels is needed.

4.9.4 Recommendations Based on the evaluation of the existing facility above and additional issues noted above, the following is recommended: Table 4-8 Septage Receiving Recommendations

Issues Recommended Improvements Issues with tank access to Either improve access to existing tank or install a new tank for remove grit and rocks from first grit removal tank Need better monitoring of tank Install level sensors with SCADA connection levels

4.10 Sludge Storage and Processing Facilities 4.10.1 Existing Septage and waste activated sludge (WAS) are combined in the facilities sludge holding tank (“blended sludge tank”) which has a capacity of 115,000 gallons. The sludge holding tank has two Davis EMU submersible mixers, each rated for 5,546 gpm. In current operation the mixers are rarely used. Sludge is pumped from the holding tank to the thickening equipment by two Diadisk double-disk semi-positive displacement pumps that are rated at 250 gpm at 25-feet of total dynamic head (TDH). Sludge is thickened by three Somat Som-A-Press rotary presses. Each unit is rated at 250 gpm and designed to accept an average feed rate of 0.5–1.5% solids and thicken to 5–8% solids. Once thickened, sludge flows by gravity to the thickened sludge tanks for storage. Two thickened sludge Diadisk pumps, rated at 450 gpm at 32 TDH, are used to pump thickened sludge to tanker trucks which are used to haul the thickened sludge offsite. Overflow from the blended sludge tank is directed to the influent wet well.

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4.10.2 Evaluation The sludge processing facilities were originally designed to thicken to 5-8% solids. Currently, the facility is thickening to 0.5–2.5% solids. The reduced performance may be due to issues with conveying sludge through the discharge pipe at the end of the sludge hopper, but is likely mainly a result of sludge being processed through the thickening process at a very high rate in order to maximize the working volume of the sludge holding tank. The sludge budget is currently approximately $200,000 annually for hauling and disposal. Improvements to the existing system may allow for this budget to be reduced by being able to send out a more concentrated sludge. The individual aspects of the sludge storage and processing facilities will be addressed below:

4.10.3 Un-thickened Sludge Storage Currently, the facility has one 115,000 gallon storage tank. Current and future septage and sludge quantities are shown below: Table 4-9 Falmouth Sludge Quantities

Current (gpd) Design (gpd)(1) Future Design (gpd)(2) Average 37,595 51,087 59,935 Peak Week 85,548 62,320 (max flow) 71,040 (max flow) Notes 1 Design and future design WAS and septage volumes are from the ‘Falmouth Wastewater Treatment Facility Improvements Preliminary Design Information Package’ prepared by Maguire Group in 2002. The design flow from the Preliminary Design Information Package is 1.2 mgd. The design future flow from the Preliminary Design Information Package is 1.4 mgd. 2 The design in the Preliminary Design Information Package was based on a tank capacity of 200,000 providing the facility with four days of storage. Typically, it is advantageous to have at least enough storage capacity to hold three days of un-thickened sludge at peak week conditions. This will allow for storage so that processing won’t be required during a long holiday weekend. Currently there is enough capacity for 1.3 days storage under these conditions. An additional advantage of having increased storage capacity is that one tank could be filled while the other tank is settling and decanting. This would allow the resting tank to send a thicker sludge to the Somat units and a cleaner decant to the SBRs. This is also very critical with respect to managing sludge inventory and reducing the recycle loads returned to the SBR. In effect, adding an extra tank will help to maximize the SBR capacity and maximize performance of the liquid treatment and solids processing systems. A new tank would include the installation of submersible mixers and a mechanism such as a telescoping valve to decant. The existing tank could also be retrofitted with a telescoping valve to provide for consistent operations between the new and the original tanks.

4.10.4 Sludge Pumping The sludge pumps in the Sludge Processing Building are by DiaDisk. The pumps used in the Sludge Processing Building are duplex and triplex pumps. DiaDisk still manufacturers pumps, but no longer appears

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to be a major supplier, especially in this area of the country. Based on discussions we had with their parent company—Fluid Tech Group—the triplex pumps they supplied for Falmouth are the only such pumps they have ever supplied. The DiaDisk pumps, especially the triplex units, present maintenance challenges due to the close proximity of the individual pump components to each other and because there currently is no means to isolate the individual pump components. These pumps are showing signs of failure and age and should be replaced. Our recommendations would be to replace these pumps with more common sludge pumps available on the market that have better design features and performance such as those supplied by Penn Valley Pump. It should also be noted that if changes are made to sludge processing as described below, these pumps would require replacement in order to pump the thicker sludge from the holding tanks to the sludge thickening unit. Another issue in this pump room is the lack of a sludge grinder. A grinder is recommended to protect pumping systems and is especially needed given the limited screening available at the septage receiving area.

4.10.5 Sludge Processing There are few remaining Somat units in municipal service and, at this time, the support for this equipment is limited to replacement parts (no improvements are being made). The unit is mainly serving industrial applications with more consistent sludges than septage. The major issue with this process is the inability of the plant to effectively thicken sludge to 5-8%. Several options exist for improving the solids concentration of the sludge that leaves the facility including: x Modify existing. This would include the following modifications:  modify the means by which sludge enters the thickened sludge tanks either by: ƒ using a progressive cavity pump to pump to either thickened sludge tank; or ƒ moving the Somat unit closer to Thickened Sludge Tank No. 1 to allow a more direct discharge through a modified piping alignment.  replace the polymer feed system x Install a new thickening device such as a rotary drum thickener. The Rotary Drum thickener would thicken sludge like the Somat, but is a technology that is currently more commonly used for this application and that is well supported. Alternately a gravity belt thickener could be used, however the advantage of the rotary drum technology is that it is a closed process and is typically preferred by operators. Installing a new thickening technology is unlikely to require significant changes to the Sludge Processing area since the process goals are still the same in that it would be designed to achieve a solids concentration of 5-8%. x Install a new sludge dewatering system. There are many dewatering systems available today including belt filter presses, centrifuges, screw presses and rotary presses. Belt presses were commonplace years ago and although they are simple to operate, they lead to a very humid environment. Centrifuges have been popular from time to time, but they require a great deal of energy and can be quite noisy. Technologies like the screw press and rotary press are popular because they are enclosed, like the centrifuge, offer low horsepower requirements like the belt press

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and yield a solids concentration somewhere between the belt press and centrifuge. However, using a dewatering technology is somewhat uncommon for a plant of this size and would be a drastic change in direction from the facilities that currently exist. The technologies may not fit well and may require some structural changes to the building. The sludge would also require a conveyor and a dumpster area surrounded by a building. The thickened sludge tanks would no longer be used as thickened sludge tanks, but with some modifications they may be able to be used as additional un- thickened sludge storage capacity. Without a more detailed analysis of the goals the Town has for the future of their sludge disposal as well as a detailed discussion about sludge disposal options now and in the future, we would not recommend making a major change like this. Other recommendations that would be part of any option above include the following: x Polymer injection into the septage and WAS pipes that feed the un-thickened sludge tanks. This would serve as a backup to the Somat unit to help provide an alternate means of additional thickening capabilities. Thickening percentages obtained by polymer addition alone are highly dependent on the mixture of septage and WAS, but with the plant superintendent having experience with this means of thickening, the small cost of providing additional polymer injection points is well worth it with this becoming at least a backup means of thickening (which most facilities do not have). x Provide bypass piping around the thickening unit in the event that the thickening unit cannot be used. 4.10.6 Thickened Sludge Storage No major changes outside of what was already described above are recommended.

4.10.7 Operational Issues In addition, the following issues were identified:

x Operators installed a temporary submersible pump into the sludge holding tank in order to increase its capacity and allow decant to be taken off the top of the tanks. Mixing occurs when WAS and septage are introduced into the tank at different intervals, making it difficult to decant liquid off the top of the tank. x The existing Somat unit is currently used for septage processing, which it was not designed to handle. This is causing higher abrasion on screens than the screens were designed for. Screens have been replaced once since the unit was installed in 2005. x The two thickened sludge tanks are interconnected and are only fed through one tank. One tank cannot be taken offline independently for maintenance. x The polymer addition system, manufactured by Polymore, is made in Germany making repairs and part replacements, which need to be ordered from Europe, a difficult and expensive process. x The electrical room in the Sludge Processing Building opens into the processing area where moist air is currently corroding the electrical equipment. The fire alarm system has also been affected and is currently showing signs of corrosion as well. 4.10.8 Recommendations Based on the evaluation of the existing facility and additional issues noted above, the following is recommended:

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Table 4-10 Sludge Processing Recommendations

Issues Recommended Improvements Un-thickened Sludge Tank and - Add one new tank with mixers need for storage over three day - Install telescoping valves in the new and existing tank to period at max week conditions decant liquid Sludge Pump problems including - Replace pumps component failure and maintenance challenges Sludge Processing inefficiencies - Relocate Somat unit to allow for more direct sludge discharge to Thickened Sludge Tank No. 1 - Replace polymer system - Provide optional polymer injection into un-thickened septage and WAS sludge lines - Provide piping bypass around Somat units Operational Issues - Provide spare screens as spare parts to extend life of Somat units - Provide exterior entry for Electrical Room and replace interior door with an observation window - Replace electrical equipment impacted by corrosion The Somat unit is not a unit that would be recommended for this application if the process were being designed today or if it were to be replaced. However, the plan above represents a cost effective means of improving existing operations. The recommendations for improving the sludge processing area is intended to help the facility manage its recycle streams which in turn should help to produce a thicker sludge and help in the efforts to meet a strict nitrogen limit, but they may also pay for themselves. It should be noted that if the average solids concentration increased from 2% to 4%, then the annual sludge hauling cost would decrease from $210,000 to $150,000. Sludge processing improvements are estimated to be approximately $830,000, which results in a simple payback of thirteen years. In other words, in addition to these improvements being highly recommended to help the facility in its effort to meet a very strict nitrogen limit, the upgrade could pay for itself.

4.11 Plant Water System 4.11.1 Existing The facility has two plant water systems—a low pressure system located in the basement of the Operations Building and a high pressure system located in the denitrification filter pump pit in the SBR building. The high pressure system is a G&L Aquaforce package booster system comprised of two 125 gpm/15 hp vertical close coupled centrifugal pumps, each with a discharge pressure rating of 70 psi. The system pumps plant water from the clear well to the following locations:

x Post hydrants (2) located in the SBR tanks. These hydrants are used to control Nocardia foam, fats, oils and greases (FOG) and for tank cleaning.

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x Half-inch flushing connection (1) located on the WAS piping. The connection allows operators to periodically flush out any solids that have settled in the gravity pipe. x Freeze-proof hydrant (1) located outside near the UV channel and clear well. This hydrant is used for cleaning the UV lamps and for wash down purposes in the area. x Freeze-proof hydrants (2) next to the sludge truck fill station and blended sludge tank. x Freeze proof hydrant (1) next to the sludge thickened tanks. The low pressure system is a G&L Aquaforce package booster system comprised of two 90 gpm/5 hp vertical close coupled centrifugal pumps each with a discharge pressure rating of 40 psi. The system pumps plant water to the following pieces of equipment: x Seal water for influent wet well pumps (4), denitrification filter pumps (2), backwash pumps (2) and the waste sludge pump x Wash hose stations at the headworks screening channel, influent wet well and Sludge Processing Building. x Headworks screening x Somat sludge hopper x Polymer blend unit x Odor control unit x Plant spray hydrants

4.11.2 Evaluation The facility should be able to function with a single plant water system. This will simplify operation. One of the biggest hurdles will be the space needed to put in a new, or retrofitted, system. Additionally, any work done in the SBR building would need to meet Division 2 rating because of the sludge piping in the building.

4.11.3 Operational Issues In addition, the following issues were noted:

x Water from the post equalization tanks is used as cooling water for the compressors occasionally clogging the filter installed upstream of the system. Potable water could be used for this application. x The variable frequency drives (VFDs) on the plant water pump in the SBR building don’t work. x There is no non-potable water interconnection with plant water that could be used in the event of a plant water system failure. x Many of the existing yard hydrants don’t work.

4.11.4 Recommendations Table 4-11 Plant Water System Recommendations

Issues Recommended Improvements Plant Water System  It is understood that the two existing plant water systems Improvements will be interconnected by plant personnel and VFDs will be replaced to try to improve the existing system.

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4.12 Chemical Feed Systems 4.12.1 Existing The facility uses or has used three chemicals over the years as part of their treatment process. These include sodium hypochlorite (which is no longer used), sodium hydroxide and methanol The original facility had a sodium hypochlorite feed system. This system was located in the basement of the Operations Building. Shortly after the most recent plant upgrade, this existing sodium hypochlorite system started to be used as a sodium hydroxide feed system to add alkalinity to the wastewater. The denitrification filter requires supplemental carbon due to a lack of carbon in the secondary effluent. The original intent was to use methanol to provide this. The methanol feed system is located behind the SBR Building and consists of a bulk storage tank, day tank, transfer pump, chemical metering pumps, and associated piping. Although methanol is the most commonly used supplemental carbon source, other types of supplemental carbon are available in the marketplace.

4.12.2 Evaluation The existing sodium hypochlorite feed system is currently being used to feed sodium hydroxide. The tank and piping system are both showing signs of leaks. This system should be demolished and a storage and delivery system that is compatible with sodium hydroxide should be installed. This system could be installed in the same location as the existing sodium hypochlorite system and would require replacement tanks, pumps, piping and accessories. The existing methanol feed system appears to have properly accommodated the flammable liquid. However because of the NFPA rating of the SBR building any potential future connections for the system made inside the SBR building should be reviewed with the local Fire Marshall during design. If the Town desires a change to a different non-flammable chemical, some changes to the system would be needed. Options that exist include Micro C and similar products offered by EOS or a dilute form of methanol. All of these options would provide a non-flammable option for the Town. With these options a connection inside the building, if needed, would likely be acceptable. However, all of these options freeze at normal winter temperatures. Thus, at a minimum, the chemical piping would need to be heat traced and the heating system in the pump building should be replaced. In addition, a change in the chemical would lead to a need to change the chemical feed pumps. It should be noted that some of the EOS products have been found to lead to more growth and thus to more sludge production. These effects are still being studied but both were noted by Severn Trent as an observed impact. Further discussions should be had with the Town on the type of chemical to use for supplemental carbon before one is chosen.

4.12.3 Operational Issues Other issues that were identified include:

x There are currently no automated controls for alkalinity addition. x The methanol feed point is in a poorly mixed area.

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4.12.4 Recommendations Based on the evaluation of the existing facility above and additional issues noted above, the following is recommended: Table 4-12 Alkalinity System Recommendations

Issues Recommended Improvements An existing sodium hypochlorite Replace this system in its entirety with new equipment - feed system is being used to feed including a new tank, pumps, piping and accessories. sodium hydroxide Lack of automated feed controls The feed rate for the sodium hydroxide feed system should be for alkalinity addition flow paced.

Table 4-13 Supplemental Carbon System Recommendations

Issues Recommended Improvements A change to a non-flammable At a minimum all piping will need to be heat traced and the supplemental carbon is desired heating system in the Pump Building should be replaced. Depending on the chemical that is chosen, the tank and pumps may require replacement also due to higher water content and possible dilution factors. Methanol addition occurs in an Coordinate with Severn Trent and determine best location to area with poor mixing add methanol such as by injecting it into the filter feed pump discharge piping. The product that is used may need to be a dilute form of methanol to avoid fire risk issues that are inherent with 100% methanol.

4.13 Odor Control Facilities 4.13.1 Existing The facility has three odor control systems as described below:

1. The facility has a biofilter, composed of bioballs (installed 2005), which is designed to treat air from the influent wet well and sludge processing facilities. 2. Two Calgon carbon systems were installed in the basement of the Operations Building (installed around 1985) to treat odor from Septage. 3. The facility has a biofilter next to the operations building.

4.13.2 Evaluation Guidance documents only address in ground biofilters. The other two systems are engineered systems that have manufacturer-specific maintenance requirements.

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The media in the biofilter next to the Operations Building needs to be replaced. TR-16 notes that the useful media life for a biofilter is typically two to four years. TR-16 also recommends supplementing wood-based media with compost at volumetric rations of 5-to-1 to 10-to-1 in order to add nutrients and microbial seeding.

4.13.3 Operational Issues x The Sludge Processing Facility biofilter is not operational. x The Calgon Carbon system had air balancing issues, was not felt to be necessary, and is no longer used. x The wood chips in the Operations Building biofilter need to be replaced.

4.13.4 Recommendations Based on the evaluation of the existing facility above and additional issues noted above, the following is recommended: Table 4-14 Odor Control Recommendations

The Sludge Processing Building The unit was installed to treat odors. It is not recommended for biofilter is not functional replacement unless odors become an issue at the facility. They are not an issue now. The Calgon Carbon System in The unit was installed in ~1985 to treat odors. It is not the Operations Building is not recommended for replacement unless odors become an issue functional at the facility. They are not an issue now. The Biofilter media requires Replace biofilter media with the facilities operations and replacement maintenance budget.

4.14 Operations Building 4.14.1 Existing The existing Operations Building was built in 1986. This building served as the single location for office, electrical and process equipment for the original plant. Since the upgrade in 2005, this building has continued to serve as the main office area and also has some functions related to process and maintenance.

4.14.2 Evaluation This building has a combination of facilities that are either fully in use or partially in use. The evaluation will be done based on the different areas of the Building. 1. Building Structure/Exterior—The main issues that have been identified with the structure are as follows:

a. Brick exterior is in need of repointing b. Windows are old and replacement would yield better building efficiency c. A leak in the roof has developed. The roof was recently replaced. Although it has a current small leak, this is unlikely to require a major expenditure to address.

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2. Office/Lab Area—The major issues that have been identified with this portion of the building include the following:

a. Office Area—The main office area is open with no privacy or environmental controls. An office expansion was planned in the past to include one or two independent office spaces. b. Air Conditioning—This area is currently not adequately air conditioned. The lab has an undersized air conditioner which does not meet the quality control standards for labs. 3. MCC and Generator Room—The MCC room contains electrical equipment that is beyond its design life. The generator has exceeded its design life as well. When equipment is beyond its design life, it starts to become difficult to get spare parts. This is a concern, but it may not be a top priority as long as parts can still be obtained. 4. Basement Process Equipment (not including chemical delivery and plant water)—In general, all of the process equipment has exceeded its life expectancy and should not be counted on to reliably last much longer. Some equipment is no longer in use and could be demolished to free up possible storage space. However, as with the electrical equipment, much of this equipment can still be repaired and could continue to be used as long as parts remain available. (Equipment still in use are described under “Operational Issues” below.) 5. Basement Non-Process Equipment—The main non process equipment in the basement is the boiler and potable water booster pumping system. One boiler has been replaced recently and the other requires replacement. The booster pumps have exceeded their design life and are in need of repair. This system should be replaced.

4.14.3 Operational Issues In addition, the following issues were noted: x The facility has two R.B. Carter 50 gpm pneumatic septage ejector pumps. The pumps are over 20 years old. The pumps are reliable and parts are fairly easy to obtain but they are past their useful service life. x The facility has two Quincy Air Compressors (Model 5120) for the septage ejector pumps. The compressor for the pumps is also over 20 years old, but one has been repaired recently. This air compressor model is still produced and parts are available. x The check valves for the septage ejector pumps should be in the vertical run of piping to operate properly. x The facility has three Roots Rotary Lobe Blowers for septage, which were placed in service in 1986. Each blower is 20 horsepower and has a capacity of 70-340 scfm. The blowers are over 20 years old. Parts are still readily available.

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4.14.4 Recommendations Based on the evaluation of the existing facility above and additional issues noted above, the following is recommended: Table 4-15 Operations Building Recommendations

SHORT-TERM IMPROVEMENTS

Issues Recommended Improvements Building/Structure Exterior Building/Structure Exterior - Windows - Replace Windows - Repointing of Bricks - Repoint Bricks - Repair roof leak Office/Lab Area Office/Lab Area - Lack of Air Conditioning - Provide proper air conditioning in the lab MCC and Generator Room None Basement Process Equipment No major changes, but some improvements could be made on a case by case basis such as relocation of septage ejector check valves Basement Non-Process Replace one boiler and the potable water booster pumping Equipment system

LONG-TERM IMPROVEMENTS

Issues Recommended Improvements Building/Structure Exterior None - None Office/Lab Area Office/Lab Area - Individual office space - Building expansion for individual office space - Lack of Air Conditioning - Provide air conditioning for office area (this will include door replacement and other measures needed for better containment of cool air) MCC and Generator Room Replace all MCC equipment and generator Basement Process Equipment All equipment that has exceeded its design life and is still in use should be replaced. Basement Non-Process None Equipment

4.15 Other Areas 4.15.1 Existing This section is intended to cover issues that do not fit in any of the previous sections.

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4.15.2 Evaluation Not applicable.

4.15.3 Operational Issues x The containment area for the two steel diesel fuel storage tanks outside the SBR building needs to be covered.

4.15.4 Recommendations Based on the evaluation of the existing facility above and additional issues noted above, the following is recommended: Table 4-16 Other Areas Recommendations

Issues Recommended Improvements The containment area for the two Install a roof over the tanks. steel storage tanks outside the SBR building needs to be covered.

5 COST ESTIMATES Estimated capital costs for the recommended improvements are presented in Table 5-1. These costs do not include anything that is referred to as a long term improvement in this memorandum. These long term improvement recommendations were only provided for informational purposes. The costs in Table 5-1 are presented in December 2012 dollars. Sources of construction cost estimates include construction bid tabulations for similar projects, information and costs from manufacturer’s representatives and commercial cost estimating guides. Costs for engineering and technical services during design and construction, fiscal, legal and administrative costs, and project contingency were added to the estimated construction cost to determine total project cost. The recommended improvements listed in Table 5-1 are required to comply with the Town’s groundwater discharge permit (as modified through a 2012 Settlement Agreement), to improve consistency and stability of the wastewater treatment system, to ensure sufficient treatment capacity for the added wastewater load from the Little Pond Service Area, and to address the odor at the Service Road vent. These improvements have been screened and evaluated to make the most of existing facilities and to focus on the most essential improvements. The most expensive of the recommended improvements, sludge processing facility improvements, is expected to pay for itself within approximately thirteen years, by reducing the volume of sludge hauled from the facility, thereby reducing the sludge hauling portion of the Wastewater Division annual operating budget by as much as $60,000 from $210,000 per year to as little as $150,000 per year (all costs are based on the Town’s current sludge hauling contract and are in 2012 dollars).

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Table 5-1 Engineers Probable Estimate of Cost

Description Cost Effluent Flow Measurement Improvements $210,000

Alkalinity System Improvements $210,000

Methanol System Improvements $130,000

Sludge Processing Improvements $850,000

Sequencing Batch Reactor Improvements $310,000

Denitrification Filter Improvements $500,000

Service Vent Improvements $390,000

Ultraviolet Disinfection Improvements $60,000

Septage Receiving Improvements $130,000

Influent Wet Well Improvements $70,000

Operations Building Improvements $210,000

Other Areas Improvements $20,000

Subtotal of Construction Cost Estimate $3,100,000

Contingency $770,000

Total Construction $3,900,000

Design and Bid Phase Engineering and Permitting Allowance $470,000

Legal, Fiscal, and Construction Engineering Allowance $510,000 Total Construction Cost with Contingency $4,900,000 (December 2012 dollars; ENR = 9412)

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The overall cost for the project has been broken down into two phases in Table 5-2 and Table 5-3. The two phases are divided based on when they are projected to be presented at Town meeting and their estimated construction schedules. Costs in these two tables are based on construction costs projected to the mid-point of construction for each phase of the project. Expected mid-point of construction for Phase 1 is Spring 2013. Phase 2 construction mid-point is expected to commence in Winter 2014.

Table 5-2 Engineers Probable Estimate of Cost—Phase 1 Improvements

Description Cost Effluent Flow Measurement Improvements1 $380,000

Design and Bid Phase Engineering and Permitting Allowance $470,000 Total Construction Cost with Contingency $850,000 (December 2012 dollars; ENR = 9412) Inflation Increase to Mid-Point of Project2 $20,000

Total Construction Cost with Contingency2 $900,000 Notes: 1 Cost includes increase for small project factor allowances, electrical and instrumentation, construction engineering, and contingency. 2 Three percent per year inflation assumed. 3 Construction costs rounded to two significant digits.

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Table 5-3 Engineers Probable Estimate of Cost—Phase 2 Improvements

Description Cost Alkalinity System Improvements $210,000

Methanol System Improvements $130,000

Sludge Processing Improvements $850,000

Sequencing Batch Reactor Improvements $310,000

Denitrification Filter Improvements $500,000

Service Vent Improvements $390,000

Ultraviolet Disinfection Improvements $60,000

Septage Receiving Improvements $130,000

Influent Wet Well Improvements $70,000

Operations Building Improvements $210,000

Other Areas Improvements $20,000

Subtotal of Construction Cost Estimate $2,900,000

Contingency $730,000

Total Construction $3,600,000

Legal, Fiscal, and Construction Engineering Allowance $470,000 Total Construction Cost with Contingency $4,100,000 (December 2012 dollars; ENR = 9412) Inflation Increase to Mid-Point of Project1 $250,000 Total Construction Cost with Contingency $4,400,000 (Expected Construction Cost—December 2014 dollars) 1 Three percent per year inflation assumed. 2 Construction costs rounded to two significant digits

G:\86\15097\WP\Memos\Technical Memos\Final Submittal\Final Submittal\WW-1 WWTF and Vent Evalaution\WW-1 Tech Memo.docx 33

Appendix WW-1-A Town of Falmouth Modified Groundwater Discharge Permit SE#4-168

Appendix WW-1-B Design Concentrations and Loadings

Appendix WW-1-C AquaAerobics Preliminary Design Reports

Project E-Mail Correspondence ID#: AAE-114005

Attention: Anastasia Rudenko Date: December 4, 2012 Company: GHD Phone#: 774/470-1637 E-Mail: [email protected] From: Tamera Knapp Project: FALMOUTH UPGRD MA

Confidentiality Notice: This page, and any accompanying pages, may contain information which is confidential or privileged and is intended for the sole use of the recipient named above. If you are not the intended recipient, please be aware that any disclosure, copying, distribution or use of, is prohibited.

Reference: Design Options

Anastasia,

Per our discussion, please take a look at the attached preliminary design (#132822) for adding a third basin to the system at Falmouth, MA.

We've also attached a copy of the design summary (#132834) showing the existing dual basin system running at its maximum flow rates based on the updated influent loadings. I need to apologize at this point, as I told you that no additional equipment would be needed to reach 0.989 MGD through the existing basins. Because I was looking at two different summaries and confusing them as the same one, I need to correct my statement. We would need to add two additional diffuser racks to each existing basin in order to achieve the 0.989 MGD as an average flow.

Without adding any equipment, the system can treat 0.85 MGD, as shown in design Summary #132838. It would be intuitive to think that with two basins, the average flow would be 66% of what can be handled with three basins, and if the peak flow was also proportional, that would be true. However in this case, we are using the same peak flow of 2.2 MGD in all of the different options, which means that in the two basin system, the LWL is lower than it is in the three basin system when the same HWL is maintained. With this lower LWL, the total mass of MLSS that can be carried per basin in the dual basin system is lower than that in the three basin system, which leads to less per basin process capacity in the dual basin system than if the same basins were part of a three basin arrangement.

Preliminary pricing for adding the third basin to the system is $489,509, and includes freight to the jobsite and our standard start-up supervision services. Within this, we've also included all of the components for the third basin that weren't previously part of our scope for the first two basins. For there, we've assumed our standard manufacturers and materials would be acceptable.

Preliminary pricing to add two diffuser racks to each of the two existing basins is $72,638, also including O&M Manual Updates, freight and start-up supervision. Please note that, as discussed, we've assumed that all existing components that were not within our scope of supply when these basins were installed will still work after the addition of the two new racks.

If you have any questions, or need additional information, please let us know.

Kind regards,

Tamera Knapp Project Applications Engineer [email protected]

CC: Technology Sales Associates / ph#: 978/838-9998 / fx#: 978/838-9897 Ken Kaiser / [email protected]

Aqua-Aerobic Systems, Inc. Bernie Eiswert, Marsha Elliott

Page 1 of 1 AquaSBR - Sequencing Batch Reactor - Design Summary Design#: 132838 Project: FALMOUTH UPGRD MA Option: Preliminary Design Upgrade (2 Basin No New Equipment) Designed by Jim Aitkenhead on Tuesday, December 4, 2012

DESIGN INFLUENT CONDITIONS Avg. Design Flow = 0.85 MGD = 3213 m3/day Max Design Flow = 2.2 MGD = 8316 m3/day Effluent DESIGN PARAMETERS Influent mg/l Required <= mg/l Anticipated <= mg/l Bio/Chem Oxygen Demand: BOD5465 BOD530 BOD5 30 Total Suspended Solids: TSS895 TSS 30 TSS 30 Total Kjeldahl Nitrogen: TKN 56 TKN 1.50 TKN 1.50 Ammonia Nitrogen: -- -- NH3-N 0.50 NH3-N 0.50 Oxidized Nitrogen: -- -- NOx-N 1.50 NOx-N 1.50 Total Nitrogen: -- -- TN3 TN 3 Total Inorganic Nitrogen: -- -- TIN 2 TIN 2

SITE CONDITIONS Maximum Minimum Design Elevation (MSL) Ambient Air Temperatures: 80 F 26.7 C 20 F -6.7 C 80 F 26.7 C 130 ft Influent Waste Temperatures: 68 F 20.0 C 50 F 10.0 C 68 F 20.0 C 39.6 m

SBR BASIN DESIGN VALUES Water Depth Basin Vol./Basin No./Basin Geometry:= 2 Square Basin(s) Min= 14.5 ft = (4.4 m) Min = 0.609 MG = (2,303.9 m³) Freeboard:= 2.0 ft = (0.6 m) Avg= 17.0 ft = (5.2 m) Avg = 0.715 MG = (2,706.1 m³) Length of Basin: = 75.0 ft = (22.9 m) Max = 21.0 ft = (6.4 m) Max = 0.884 MG = (3,344.9 m³) Width of Basin: = 75.0 ft = (22.9 m)

Number of Cycles: = 4 per Day/Basin (advances cycles beyond MDF) Cycle Duration: = 6.0 Hours/Cycle Food/Mass (F/M) ratio: = 0.072 lbs. BOD5/lb. MLSS-Day MLSS Concentration: = 4500 mg/l @ Min. Water Depth Hydraulic Retention Time: = 1.682 Days @ Avg. Water Depth Solids Retention Time: = 10.2 Days Est. Net Sludge Yield: = 1.290 lbs. WAS/lb. BOD5 Est. Dry Solids Produced: = 4251.5 lbs. WAS/Day = (1928.5 kg/Day) Est. Solids Flow Rate: = 500 GPM (50977 GAL/Day) = (193.0 m³/Day) Decant Flow Rate @ MDF: = 4583.0 GPM (as avg. from high to low water level) = (289.1 l/sec) LWL to CenterLine Discharge: = 2.5 ft = (0.8 m) Lbs. O2/lb. BOD5 = 1.25 Lbs. O2/lb. TKN = 4.60 Actual Oxygen Required: = 5947 lbs./Day = (2697.4 kg/Day) Air Flowrate/Basin: = 1749 SCFM = (49.5 Sm3/min) Max. Discharge Pressure: = 10.7 PSIG = (74 KPA) Avg. Power Required: = 973.7 KW-Hrs/Day

Printed:12/04/2012 2:46:06PM Aqua-Aerobic Systems, Inc. CONFIDENTIAL Page 1 of 1 AquaSBR - Sequencing Batch Reactor - Design Summary Design#: 132834 Project: FALMOUTH UPGRD MA Option: Preliminary Design Upgrade (2 Basin Maximum Flow) Designed by Jim Aitkenhead on Tuesday, December 4, 2012

DESIGN INFLUENT CONDITIONS Avg. Design Flow = 0.989 MGD = 3738 m3/day Max Design Flow = 2.2 MGD = 8316 m3/day Effluent DESIGN PARAMETERS Influent mg/l Required <= mg/l Anticipated <= mg/l Bio/Chem Oxygen Demand: BOD5465 BOD530 BOD5 30 Total Suspended Solids: TSS895 TSS 30 TSS 30 Total Kjeldahl Nitrogen: TKN 56 TKN 1.50 TKN 1.50 Ammonia Nitrogen: -- -- NH3-N 0.50 NH3-N 0.50 Oxidized Nitrogen: -- -- NOx-N 1.50 NOx-N 1.50 Total Nitrogen: -- -- TN3 TN 3 Total Inorganic Nitrogen: -- -- TIN 2 TIN 2

SITE CONDITIONS Maximum Minimum Design Elevation (MSL) Ambient Air Temperatures: 80 F 26.7 C 20 F -6.7 C 80 F 26.7 C 130 ft Influent Waste Temperatures: 68 F 20.0 C 50 F 10.0 C 68 F 20.0 C 39.6 m

SBR BASIN DESIGN VALUES Water Depth Basin Vol./Basin No./Basin Geometry:= 2 Square Basin(s) Min= 14.5 ft = (4.4 m) Min = 0.609 MG = (2,303.9 m³) Freeboard:= 2.0 ft = (0.6 m) Avg= 17.4 ft = (5.3 m) Avg = 0.732 MG = (2,771.9 m³) Length of Basin: = 75.0 ft = (22.9 m) Max = 21.0 ft = (6.4 m) Max = 0.884 MG = (3,344.9 m³) Width of Basin: = 75.0 ft = (22.9 m)

Number of Cycles: = 4 per Day/Basin (advances cycles beyond MDF) Cycle Duration: = 6.0 Hours/Cycle Food/Mass (F/M) ratio: = 0.084 lbs. BOD5/lb. MLSS-Day MLSS Concentration: = 4500 mg/l @ Min. Water Depth Hydraulic Retention Time: = 1.481 Days @ Avg. Water Depth Solids Retention Time: = 8.8 Days Est. Net Sludge Yield: = 1.290 lbs. WAS/lb. BOD5 Est. Dry Solids Produced: = 4946.3 lbs. WAS/Day = (2243.6 kg/Day) Est. Solids Flow Rate: = 500 GPM (59308 GAL/Day) = (224.5 m³/Day) Decant Flow Rate @ MDF: = 4583.0 GPM (as avg. from high to low water level) = (289.1 l/sec) LWL to CenterLine Discharge: = 2.5 ft = (0.8 m) Lbs. O2/lb. BOD5 = 1.25 Lbs. O2/lb. TKN = 4.60 Actual Oxygen Required: = 6919 lbs./Day = (3138.5 kg/Day) Air Flowrate/Basin: = 2162 SCFM = (61.2 Sm3/min) Max. Discharge Pressure: = 10.7 PSIG = (74 KPA) Avg. Power Required: = 1124.6 KW-Hrs/Day

Printed:12/04/2012 2:36:17PM Aqua-Aerobic Systems, Inc. CONFIDENTIAL Page 1 of 1 FALMOUTH UPGRD MA Design#: 132822

Option: Preliminary Design Upgrade (3 Basin)

Designed By: Jim Aitkenhead on Monday, December 3, 2012

The enclosed information is based on preliminary data which we have received from you. There may be factors unknown to us which would alter the enclosed recommendation. These recommendations are based on models and assumptions widely used in the industry. While we attempt to keep these current, Aqua-Aerobic Systems, Inc. assumes no responsibility for their validity or any risks associated with their use. Also, because of the various factors stated above, Aqua-Aerobic Systems, Inc. assumes no responsibility for any liability resulting from any use made by you of the enclosed recommendations.

Copyright 2012, Aqua-Aerobic Systems, Inc Design Notes

Pre-SBR

- Neutralization is recommended/required ahead of the SBR if the pH is expected to fall outside of 6.5-8.5 for significant durations.

- Coarse solids removal/reduction is recommended prior to the SBR.

SBR

- The Maximum flow, as shown on the design, has been assumed as a hydraulic maximum and does not represent an additional organic load.

- The decanter performance is based upon a free-air discharge following the valve and immediately adjacent to the basin. Actual decanter performance depends upon the complete installation including specific liquid and piping elevations and any associated field piping losses to the final point of discharge. Modification of the high water level, low water level, centerline of discharge, and / or cycle structure may be required to achieve discharge of full batch volume based on actual site installation specifics.

Aeration

- The aeration system has been designed to provide 1.25 lbs O2/lb BOD5 applied and 4.6 lbs O2/lb NH3-N applied at the design average loading conditions.

Process/Site

- The anticipated effluent Nitrogen requirement is predicated upon an influent waste temperature of 10° C or greater. While lower temperatures may be acceptable for a short-term duration, Nitrification and Denitrification below 10° C can be unpredictable, requiring special operator attention.

- Sufficient alkalinity is required for nitrification, as approximately 7.1 mg alkalinity (as CaCO3) is required for every mg of NH3-N nitrified. If the raw water alkalinity cannot support this consumption, while maintaining a residual concentration of 50 mg/l, supplemental alkalinity shall be provided (by others).

- NOTE: This system has been designed to be expandable from a phase I flow of 1.2 MGD to an ultimate, phase II flow of 1.484 MGD. This expansion will utilize the existing, phase I SBR basins. It will require the construction of an additional SBR basin. Phase I blowers may need to be rebelted and sheaved to meet phase II operating requirements. (BY OTHERS) New blowers will be provided for the new SBR basin. The engineer should give thought to piping and site layout to facilitate the expansion.

Anticipated

- The effluent Total Nitrogen limit (TN) of 3 mg/l is assumed to be comprised of 1 mg/l organic nitrogen, 1.5 mg/l NOx-N, and 0.5 mg/l NH3-N.

- The ability to meet the effluent organic nitrogen is contingent upon the system's ability to hydrolyze the influent organic nitrogen to NH3-N. A certain fraction of the organic nitrogen may be refractory and, therefore, will not be biologically converted.

- In order to meet the required Total N limit, strict operator attention will be necessary to process and operational control. It is also recommended that provisions be made for supplemental carbon source addition in order to facilitate denitrification. (BY OTHERS)

Equipment

- The basin dimensions reported on the design have been assumed based upon the required volumes and assumed basin geometry. Actual basin geometry may be circular, square, rectangular or sloped with construction materials including concrete, steel or earthen.

- Rectangular or sloped basin construction with length to width ratios greater than 1.5:1 may require alterations in the equipment recommendation.

- Biological System tanksand/or modifications are not included and shall be provided by others.

- Influent is assumed to enter the reactor above the waterline, located appropriately to avoid proximity to the decanter, splashing or direct discharge in the immediate vicinity of other equipment.

12/03/2012 10:58:50AM Aqua-Aerobic Systems, Inc CONFIDENTIAL Page 2 of 6 FALMOUTH UPGRD MA / Design#: 132822 - If the influent is to be located submerged below the waterline, adequate hydraulic capacity shall be made in the headworks to prevent backflow from one reactor to the other during transition of influent.

- The control panel for Phase II has been sized to incorporate Phase I equipment.

- The control panel does not include motor starters. Motor starters should be provided in a separate MCC (by others).

- Aqua-Aerobic Systems, Inc. (AASI) is familiar with the Buy American provision of the American Recovery and Reinvestment Act of 2009 as well as other Buy American provisions (i.e. FAR 52.225, EXIM Bank, USAid, etc.). AASI can provide a system that is in full compliance with Buy American provisions. As the project develops AASI can work with you to ensure full compliance with a Buy American provision, if required. Please contact the factory should compliance with a Buy American provision be required.

12/03/2012 10:58:50AM Aqua-Aerobic Systems, Inc CONFIDENTIAL Page 3 of 6 FALMOUTH UPGRD MA / Design#: 132822 AquaSBR - Sequencing Batch Reactor - Design Summary

DESIGN INFLUENT CONDITIONS Avg. Design Flow = 1.484 MGD = 5610 m3/day Max Design Flow = 2.2 MGD = 8316 m3/day Effluent DESIGN PARAMETERS Influent mg/l Required <= mg/l Anticipated <= mg/l Bio/Chem Oxygen Demand: BOD5 465 BOD5 30 BOD5 30 Total Suspended Solids: TSS 895 TSS 30 TSS 30 Total Kjeldahl Nitrogen: TKN 56 TKN 1.50 TKN 1.50 Ammonia Nitrogen: -- -- NH3-N 0.50 NH3-N 0.50 Oxidized Nitrogen: -- -- NOx-N 1.50 NOx-N 1.50 Total Nitrogen: -- -- TN 3 TN 3 Total Inorganic Nitrogen: -- -- TIN 2 TIN 2

SITE CONDITIONS Maximum Minimum Design Elevation (MSL) Ambient Air Temperatures: 80 F 26.7 C 20 F -6.7 C 80 F 26.7 C 130 ft Influent Waste Temperatures: 68 F 20.0 C 50 F 10.0 C 68 F 20.0 C 39.6 m

SBR BASIN DESIGN VALUES Water Depth Basin Vol./Basin No./Basin Geometry: = 3 Square Basin(s) Min = 16.6 ft = (5.1 m) Min = 0.700 MG = (2,650.9 m³) Freeboard: = 2.0 ft = (0.6 m) Avg = 19.6 ft = (6.0 m) Avg = 0.824 MG = (3,119.1 m³) Length of Basin: = 75.0 ft = (22.9 m) Max = 21.0 ft = (6.4 m) Max = 0.884 MG = (3,344.9 m³) Width of Basin: = 75.0 ft = (22.9 m)

Number of Cycles: = 4 per Day/Basin (advances cycles beyond MDF) Cycle Duration: = 6.0 Hours/Cycle Food/Mass (F/M) ratio: = 0.073 lbs. BOD5/lb. MLSS-Day MLSS Concentration: = 4500 mg/l @ Min. Water Depth Hydraulic Retention Time: = 1.666 Days @ Avg. Water Depth Solids Retention Time: = 10.1 Days Est. Net Sludge Yield: = 1.290 lbs. WAS/lb. BOD5 Est. Dry Solids Produced: = 7422.6 lbs. WAS/Day = (3366.9 kg/Day) Est. Solids Flow Rate: = 500 GPM (88999 GAL/Day) = (336.9 m³/Day) Decant Flow Rate @ MDF: = 3056.0 GPM (as avg. from high to low water level) = (192.8 l/sec) LWL to CenterLine Discharge: = 4.6 ft = (1.4 m) Lbs. O2/lb. BOD5 = 1.25 Lbs. O2/lb. TKN = 4.60 Actual Oxygen Required: = 10382 lbs./Day = (4709.3 kg/Day) Air Flowrate/Basin: = 1740 SCFM = (49.3 Sm3/min) Max. Discharge Pressure: = 10.7 PSIG = (74 KPA) Avg. Power Required: = 2428.9 KW-Hrs/Day

12/03/2012 10:58:50AM Aqua-Aerobic Systems, Inc CONFIDENTIAL Page 4 of 6 FALMOUTH UPGRD MA / Design#: 132822 Equipment Summary

AquaSBR

Influent Valves

1 Influent Valve(s) will be provided as follows:

- 12 inch electrically operated plug valve(s). Influent Baffles

1 Influent Baffle(s) will be provided as follows:

- 304 stainless steel 4x4 Influent Baffle Assembly(ies). Mixers

1 AquaDDM Direct Drive Mixer(s) will be provided as follows:

- 25 HP Aqua-Aerobic Systems Endura Series Model FSS DDM Mixer(s). Mixer Mooring

1 Mixer Cable Mooring System(s) consisting of:

- #8 AWG four-conductor electrical service cable(s). - Aerial support tie(s). - Electrical cable strain relief grip(s), 2 eye, wire mesh. - 304 stainless steel mooring cable(s). - Maintenance mooring cable loop(s). - Stainless steel mooring spring(s). Decanters

1 Decanter Assembly(ies) consisting of:

- 10x9 Aqua-Aerobics decanter(s) with fiberglass float, 304 stainless steel weir, 304 stainless steel restrained mooring frame, and painted steel power section with #14-10 conductor power cable. - Decant pipe(s). - 16 inch diameter stainless steel flanged flexible joints. - 304 stainless steel linear mooring post. - 304 stainless steel dewatering support posts. - 304 stainless steel top mooring post supports. - 304 stainless steel bottom mooring post supports. - 16 inch electrically operated butterfly valve(s). Transfer Pumps/Valves

1 Submersible pump assembly(ies) consisting of the following items:

- 5 HP Submersible Pump(s) with painted cast iron pump housing, discharge elbow, and multi-conductor electrical cable. - Manual plug valve(s). - Check valve(s). - 304 stainless steel upper guide bar bracket(s). - 304 stainless steel slide rail assembly(ies). Retrievable Fine Bubble Diffusers

6 Retrievable Fine Bubble Diffuser Assembly(ies) consisting of:

- 25 diffuser tubes consisting of two flexible EPDM porous membrane sheaths mounted on a rigid support pipe with 304 stainless steel band clamps. - 304 stainless steel manifold weldment. - 304 stainless steel leveling angles. - 304 stainless steel leveling studs.

12/03/2012 10:58:50AM Aqua-Aerobic Systems, Inc CONFIDENTIAL Page 5 of 6 FALMOUTH UPGRD MA / Design#: 132822 - 304 stainless steel vertical support beam. - 304 stainless steel vertical air column assembly. - 304 stainless steel upper vertical beam and pulley assembly. - 304 stainless steel top support bracket. - 3" EPDM flexible air line with ny-glass quick disconnect end fittings. - 304 stainless steel threaded flange. - 3" manual isolation butterfly valve with cast iron body, EPDM seat, aluminum bronze disk and one-piece steel shaft. - Ny-glass quick disconnect cam lock adapter. - 304 stainless steel adhesive anchors. - Brace angles. 1 Diffuser Electric Winch(es) will be provided as follows:

- Portable electric winch. Positive Displacement Blowers

3 Positive Displacement Blower Package(s), with each package consisting of:

- ROOTS 616 Positive Displacement Blower Package with common base, V-belt drive, enclosed drive guard, pressure gauge, pressure relief valve, and vibration pads. - 304 stainless steel anchors. - 75 HP motor with slide base. - Inlet filter and inlet silencer. - Discharge silencer, check valve, manual butterfly isolation valve, and flexible discharge connector. Level Sensor Assemblies

1 Pressure Transducer Assembly(ies) each consisting of:

- Submersible pressure transducer(s). - Mounting bracket weldment(s). - Transducer mounting weldment(s). - 304 stainless steel anchors. 1 Level Sensor Assembly(ies) will be provided as follows:

- Float switch(es). - Float switch mounting bracket(s). - 304 stainless steel anchors. Instrumentation

3 Dissolved Oxygen Assembly(ies) consisting of:

- Hach LDO dissolved oxygen probe with replaceable sensor cap and electric cable. Probe includes stainless steel stationary bracket and retrievable pole probe mounting assembly. One (1) probe per basin. - Hach SC200 controller and display module(s). Controls

Controls wo/Starters

1 Controls Package(s) will be provided as follows:

- NEMA 12 panel enclosure suitable for indoor installation and constructed of painted steel. - Fuse(s) and fuse block(s). - Allen Bradley SLC5/05 central processing unit with 64K memory and Ethernet connection. - Panelview Plus 6 1000 color touchscreen display. - Remote Access Ethernet Modem.

12/03/2012 10:58:50AM Aqua-Aerobic Systems, Inc CONFIDENTIAL Page 6 of 6 FALMOUTH UPGRD MA / Design#: 132822

Appendix WW-1-D S&W Collection System Odor Control Evaluation Report

Appendix WW-1-E AquaAerobics SBR Process Guarantee