Lombardo Associates, Inc.
Representative Project Descriptions

Municipal & Private
Wastewater Applications
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Mayo, MD
Town of Woodstock, NY
Town of Mashpee, MA
Los Osos, San Luis Obispo, CA
Little Neck- Ipswich, MA

PROJECT DESCRIPTION –MAYO PENINSULA, MD
Integrated Decentralized Wastewater Management System
Project:

Mayo Peninsula Wastewater
Management System - 900,000 gpd
8,000 people

Client:Anne Arundel County
Department of Public Works
2662 Riva Road
Annapolis, MD 21401

Wastewater
Engineer: Pio Lombardo, P.E.
Lombardo Associates, Inc.
Boston, MA & Malibu, CA
617-964-2924
Pio@LombardoAssociates.com
www.LombardoAssociates.com

Lombardo Associates, Inc. (LAI) was the Engineer of Record for the Mayo Peninsula Wastewater
Collection System which serves 3,000 connections within a 9 square mile area adjacent to Annapolis,
MD, with a population of approximately 8,000, where integration of growth management and use of
wetlands for wastewater treatment were key attributes. Construction completion occurred in 1992 for the$60 million project.
LAI designed & implemented an innovative decentralized wastewater management project using:
1. On-site systems
2. Cluster wastewater system
3. Large communal system using:¾ 40 miles of septic tank effluent collection system (50% gravity & 50% pressure)¾ 900,000 gallons per day (gpd) Treatment Process of: recirculating sand filters,
 constructed bulrush wetlands for nitrogen removal,
 constructed peat wetland for phosphorus removal
 UV disinfection¾ Ultimate disposal through an off-shore, submerged aquatic vegetation wetland`
Figure A: Process Flow Diagram

Integrated Phase Implementation:
The Mayo Peninsula Wastewater Collection System was completed in stages, with theCollection System and 20% of the construction occurring in year 1. Thereafter, an
additional 20% of construction occurred each year until completion. Modular development
allowed gradual investment and improved operational efficiency.
Table 1: Historical Performance
Average Data from 01/93 to 08/05

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Table 1 (right) presents the treatment
performance.

BOD

Septic
Tank
Influent

Treatment
Plant
Effluent

Reduction% ofInfluent

85.8

4.4

94.8%

55.7

2.1

96.3%

33.7

7.4

78.0%

(mg/l)

TSS(mg/l)

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Figures 1-5 (below) illustrate theprocess demonstrated in the process
flow diagram of Figure A.

Figure 1A: Typical House Septic Tank –Effluent Collection

TN(mg/l)

Figure 1B: Typical Small Pump Station

Septic Tank Cover
Porous Pavement

Figure 1C: Typical Large Pump Station

Figure 2: Aerial View of Communal
Wastewater Treatment System
Peat Wetlands
Bulrush Wetlands

Recirculating
Sand Filter (RSF)

Figure 3: Bulrush Wetland

Figure 4: Peat Wetland During Operation

Figure 5: Aerial View of Constructed Offshore

submerged aquaticvegetation wetlands

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Innovative Integrated Decentralized Wastewater Treatment System
Project:

Integrated Decentralized Wastewater System
Town of Woodstock, NY

Client: Town of Woodstock, New York

Wastewater
Engineer: Pio Lombardo, P.E.
Lombardo Associates, Inc.
Boston, MA & Malibu, CA
617-964-2924
Pio@LombardoAssociates.com
www.LombardoAssociates.com

Lombardo Associates, Inc. engineered an extensive, integrated master plan for the innovative wastewater
treatment facility in the Town of Woodstock, New York.
Severe site limitations such as shallow bedrock, high groundwater, slowly permeable soils and steep slopes called
for innovative system designs in order to overcome the aesthetic impact of the required solution on individual
properties. The project punctuated a creative planning and design effort highlighted by:o active homeowner participationo enactment of strong water conservation practices
o development of alternative system designs.
The Plan proposed the establishment of:• The Hamlet Wastewater Management
District with a centralized wastewater
system for the 460 connections.
•

Septic tank effluent collection andaquaculture treatment using UV
disinfection system with river discharge.

•

Three On-site Wastewater Management
Districts.

The implemented systems, at
a capital cost of approximately$14 million, were:o Low-cost , low energy use
sludge management system forsmall communities
o Capacity development for small communities to effectively operate & maintain wastewater treatment facilities.
o Innovative water efficiency programs or technique to reduce wastewater infrastructure costs.
o Innovative 432 connection septic tank effluent collection system using a 2-mile single-barrel siphon to avoid
pump station, discharging to a 0.23 MGD innovative draft tube oxidation ditch with vacuum drying beds , UV
disinfection and discharge to the Saw Kill River.

o Repair of 200+ residential and commercial on-site wastewater systems using a
combination of conventional and innovative systems (predominately sand filters,leachfields and mounds) in individual and cluster formats.
The Hamlet Plan was overwhelmingly
accepted by referendum (7-1 vote). 2 of the 3
proposed districts became established as thefirst On-site Wastewater Management
Districts in New York State and first large
scale septic system rehabilitation program in
the US.

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NitrexTM Technology Scenarios Plan
Conventional Sewer Systems = $500+ - $600+ million
NitrexTM Approach = $279 million
Project:

Town of Mashpee, Popponesset Bay& Waquoit Bay East Watersheds
NitrexTM Technology Scenario Plan

Wastewater
Engineer:

Pio Lombardo, P.E.
Lombardo Associates, Inc.
Boston, MA & Malibu, CA
617-964-2924
Pio@LombardoAssociates.com
www.LombardoAssociates.com

Lombardo Associates, Inc. (LAI) was retained by the
Mashpee Sewer Commission to prepare a NitrexTM
Technology based wastewater management plan for the
Town of Mashpee for the Project Planning Area (PPA)of the East Waquoit and Popponesset Watersheds. The
NitrexTM Technology based plan was to achieve the
TMDL requirements as specified by the Massachusetts
Department of Environmental Protection, and thereby
can be compared on an equal basis with theconventional sewering option.
The NitrexTM Technology Scenario Plan includes:
1.
2.
for
3.
4.

Cluster Systems
Individual Onsite NitrexTM Treatment Systems
application as:a.
Retrofit to propertiesb.
New systems
TM
Nitrex Groundwater Treatment Systema.
Pump and Treatb.
Permeable Reactive Barrier (PRB)
Hybrid of the above

A summary of the capital and annual O&M costs of theNitrexTM Technology based Scenarios are presented on
Tables 1 and 2.

Table 1. NitrexTM Scenario Costs Compared to Complete WW System
NitrexTM Technology Scenarios

Nitrex TM Technology
NitrexTM Technology
Capital Cost as % of
Capital Cost / Capital Cost as % of
Capital Cost
Sewers Connected
EDU (house)
Complete WW
to Existing WWTP &System w/ Sewers
Expansion

1. Cluster Systems$280,546,000$40,000

61%

52%

2. Individual Systems$251,970,000$30,000(1)

55%

47%

3. Groundwater Treatment$143,636,703$20,31631%

27%

4. Stearns & W heler Scenario 4 Proposed$460,000,000(2,3)
Estimates - low end$66,000

100%

85%$66,000

117%

100%

5. Stearns & W heler Scenario 1 Proposed(2,3)

Cost Estimates - high end(1)$540,000,000

MA State Tax Credit of $6,000 may be available to property owners with septic system repair.

(2)

The Stearns & Wheler proposed cost estimates in the March 2008 Draft Alternative Scenarios Analysis Report do not include allowances for landacquisition, acquisition of needed WWTPs, and treatment costs at the Falmouth and Barnstable WWTPs.
(3)

Ratio of Captial Cost are higher than the per EDU ratio due to the fact that the Stearns & Wheler proposal is to sewer more properties thanproposed by LAI.

Table 2. NitrexTM Scenarios Annual O&M
Speed of Implementation & Water Quality Improvement.
NitrexTM Technology Scenarios

Annual O&M
Costs / EDU

1. Cluster Systems$396

2. Individual Systems$551

3. Groundwater Treatment - Pump & Treat$223

4. Groundwater Treatment - PRB$122

5. Conventional Sewerage System$700 - $1,000

The NitrexTM Technology options can achieve the desired water quality
improvements more quickly than treating wastewater because treating
wastewater will require the groundwater to cleanse itself after excess
nitrogen loadings are reduced. According to the USGS, this will take 1020 years after the treatment systems are functioning. Conventional
sewering may take 10 – 20 years to complete. The NitrexTM PRB andpump and treat systems can address groundwater just prior to its reachingsurface water bodies.
In addition to the speed of implementation, these two NitrexTM options
have the benefit of treating land use nitrogen loads as well as nitrogenloads from upstream sources.

The NitrexTM Scenarios explicitly delineate the specific parcels that needto have their wastewater treated to achieve the water quality goals for the project planning area. The Onsite Scenario is similar to theCluster System Scenario, in that the same basic parcels are treated, with minimal adjustments made to account for watersheds that
require 100% removal of wastewater nitrogen. The pump and treat and PRB scenarios are presented as alternatives that offer benefits
such as significant capital and operational cost savings as well as the speed of implementation and water quality improvement. The
common factor for all scenarios is the required nitrogen removal. The groundwater pump and treat and PRB options require moregroundwater flow and quality data than is currently available, as well as specific solute transport data to accurately locate, therefore thesescenarios are strictly conceptual and for comparison purposes only.
The NitrexTM Scenarios minimize the undesired growth stimulation that typically occurs with conventional sewers. The costs forConventional Sewering with complete wastewater system and conventional sewering with connection to existing WWTP are based upon
Cape Cod comparables. A detailed PPA conventional sewer plan and costs is being developed by others.

PROJECT DESCRIPTION – LOS OSOS, CA
SAN LUIS OBISPO COUNTY, CA
Cost Competitive Decentralized Wastewater Treatment, Dispersal & Reuse Plan
Project:

Los Osos Community Wide Study
Decentralized Wastewater
Treatment System

Client:

San Luis Obispo County
Department of Public Works
San Luis Obispo, CA

Wastewater
Engineer:

Pio Lombardo, P.E.
Lombardo Associates, Inc.
Boston, MA & Malibu, CA
617-964-2924
Pio@LombardoAssociates.com
www.LombardoAssociates.com

LAI was retained to develop decentralized wastewater
treatment and dispersal/reuse scenarios for the Los
Osos Community in San Luis Obispo County, CA.
The following two (2) scenarios were developed:
1. Multiple locations within Los Osos
2. Two locations within Los Osos
Scenario 1 – Multiple Locations Within Los Osos
This scenario involves creating 7 sub-zones for the
project area, each having its own treatment anddispersal sites. The potential treatment and dispersal
sites consist of undeveloped land either on paper
streets or on undeveloped lots. Dispersal andtreatment sites are not confined to being located in
the same zone or sub-area. Sites not utilized fortreatment can be available for potential dispersal. For
each zone, reuse/dispersal with Title 22 treatedwastewater at the individual properties wasconsidered as an alternate disposal method.

Scenario 2 – Two Locations – One in Mid-Town and one inNortheast Region of Los Osos
This option will utilize two treatment locations in combination
with multiple disposal and reuse locations. Collection
system quantities are similar to those in Scenario 1, with the
exception of longer distribution piping and pump station
force mains. There will be fewer pump stations that will belarger in size and conveying wastewater over a greater
distance compared to Scenario 1.
For each zone,
reuse/dispersal with Title 22 treated wastewater at theindividual properties was considered as an alternate
disposal method.

The following Table summarizes the Capital Cost, Annual O&M and Present Worth estimates for Scenarios 1 and 2 andcompares them to the August 2007 Carollo Engineers’ Fine Screening Analysis Report estimates, using a total of 5,353 Benefit
Units (BU) from the Assessment Engineers Report.

Summary of Capital Cost, Annual O&M and Present Worth Estimates
Scenario

Project Cost ($ millions)AverageAnnualProject Cost Per BU Annual O&M
Present Worth1 ($AnnualAnnualPower Use
Cost ($(in $ millions)millions)
O&M / BU
Power Use
(kWhr)
millions)(kW)
Level 2
Level 3
Level 2 Level 3$0.019$0.026$1.5$272
2,003,333
229
$137
$179
$0.017$0.025$0.8$149
1,681,667
192
$125
$168
$0.030$2.0 - 3.1$0.033$1.6 - 3.0$0.031$2.1 - 3.2$0.033$1.7 - 3.2$0.034$1.8 - 3.9$0.037$1.4 - 3.8$0.034$2.0 - 3.1$0.037$1.6 - 3.0

Level 2
Level 3
7 Zones$101$137
2 Zones$92$135
190 AFY
STEP$144 - 180
Fine Screening Report $165 - 188
190 AFY
Gravity
Level 2 Mitigation
240 AFY
STEP$147 - 181$168 - 189
240 AFY
Gravity
550 AFY
STEP$166 - 202
Fine Screening Report $187 - 211
550 AFY
Gravity
600 AFYSTEP
Level 3 Mitigation$165 - 199$186 - 207
600 AFY
Gravity1
Using 5% interest and 40 year planning period.
2
Project cost savings of $15 - 25 million may be possible with shared septic tanks and lower 4" gravity pipe cost.
2

Scenario 1
Scenario 2 2

The LAI decentralized alternative has capital and annual O&M costs approximately 30% - 40% lower than the other identified options. Level 3
project provides the needed mitigation to arrest saltwater intrusion of the Los Osos water supply aquifer. Level 2 project requires purveyors
actions to arrest saltwater intrustion.

Little Neck
Ipswich, MA
Project Description
LAI was retained by the Feoffees of Grammar School
to design a Wastewater System for the Little Neck
Development in Ipswich, MA that complies withadministrative consent order from Massachusetts
Department of Environmental Protection (MADEP) tocorrect inadequate wastewater management incompliance with State Regulations.

Project Application Data

Location: Ipswich, MA
Site Application: Residential with Community
Center
Installation Date: July 2006

Design Profile Design Wastewater Flow: 35,000 gpd
 167 homes: 143 Seasonal and 24 Year Round
Residences

System Components.
1. Collection System
The sewer system collects wastewater from 167
houses and the community center with aconventional gravity collection system with twopump stations.
The wastewater flows to the120,000-gallon Holding Tanks either by gravity or
via force main from the two pump stations.
2. Holding Tanks and Transfer Facilities
Wastewater collected by the sewer system isconveyed to holding tanks, where it is pumped out
and transported to the Ipswich Wastewater
Treatment Plant.
3. Management Information System (MIS)The MIS developed for the Little Neck Wastewater
system enables real-time flow and operations
monitoring via the world wide web.

Long Term Solution Options
1. Connection to the Ipswich sewer system
2. Construction of an on Little Neck WWTP and clean water
connection to the Ipswich sewer system discharge pipe.
3.

Horizontal directional drilling (HDD) and connection to the
Ipswich WWTP.