Lombardo Associates, Inc. 

 

Representative Nitrogen Removal 

Project Descriptions 

 

 

 

 Cluster NitrexTM Systems 

 Test Centers & Independent Evaluations 

 Groundwater & Stormwater Treatment 

 Single Family NitrexTM Systems 

 Multi Family & Institutional NitrexTM 

Systems 

 

From To

1 2950 Beacon Court, Lusby, MD 60.00 Est. 1.97 quarterly 96.7% Sep-09 present Daniel J. Brumsted 

danb@etlannapolis.com

2 6500 Long Beach Drive, St. Leonard, MD SFR 60.00 Est. 2.80 quarterly 95.3% Sep-09 present 410-224-4304 

3 6586 Long Beach Drive, St. Leonard, MD SFR 60.00 Est. 2.95 quarterly 95.1% Sep-09 present

4 18040 Barnesville Road, Barnesville, MD SFR 60.00 Est. 7.77 quarterly 87.1% Mar-10 present Fredericktown Lab Wendy Hagan

301-293-3340 ext.22 w.hagan@fredericktownelabs.com

5 1933 Clifton Road, Virginia Beach, VA SFR 60.00 Est. 3.29 annually 94.5% Aug-09 present Universal Lab

Dan Thornton <d.thornton@universallaboratories.net>

6 Mashpee, MA Main St Villages 30 unit subdivision 55.98 3.85 93.1% May-06 present ClearWater Industries Clearwaterin@aol.com

Mark Cottrel (978) 356-0779

7 Eastham, MA Bracket Landing 40 unit subdivision 45.14 3.11 93.1% Oct-07 present Rosano Davis Donna Muzzi 781-383-8888

donnamuzzi@hotmail.com

8 Bogue Sound Elementary & Croatan High School 106.1 3.11 97.1% Jan-10 present Carteret County Board of Education

Newport, NC Kenny Pedersen (kenny.pedersen@carteretk12.org)

252-241-9681

9 Malibu Village Plaza 53.1 3.04 weekly 94.3% Jul-07 present BioSolutions, Inc. Steve Braband

Malibu, CA 818-991-9997 ext 203

sbraband@biosolutions.org

10 Stone Residence SFR 56.5 2.2 96.1% Dec-00 May-03 Barbara Rich, formerly with OR DEQ and Deschutes County, OR

LaPine, OR brbrrich946@gmail.com 541-617-4713

11 Fleming Residence SFR 68 2.65 96.1% Dec-00 Mar-03 Barbara Rich, formerly with OR DEQ and Deschutes County, OR

LaPine, OR brbrrich946@gmail.com 541-617-4713

12 St. Ignatius, MT SFR 46.1 3.4 92.6% Oct-99 Aug-01 Rebecca Dupuis

for MT Dept of Natural Resources Osprey Environmental Consulting

606 4th Avenue East

Polson, MT 59860

(406) 883-5603

osprey@centurytel.net

13 330 gpd 39.3 4.5 88.5% Oct-01 Oct-05 Mr. George Heufelder, Director

Barnstable County Department of Health

Cape Cod, MA Post Office Box 427

AVERAGE OF ALL 93.8% Barnstable, MA 02630

(508) 375-6616

gheufeld@capecod.net

Building Concepts and 

Environmental Testing Lab

Contact

Period of Operation

Total Nitrogen 

Percent (%) Removal Data Collected by

System still operational, no additional data collected. Site was part of LaPine 

Demo project

daily for 5 days once 

per month for 11 

months then 

monthly for 11 

months. 65 sample 

events total

Shopping Center - 

Restaurants & 

Retail

NitrexTM Nitrogen Removal Systems - Nitrogen Removal Performance

System still operational, no additional data collected. Site was part of LaPine 

Demo project

 monthly for 1st 18 

months then 

quarterly 

 weekly for 1st 8 

weeks, then monthly 

for next 9 months 

then quarterly 

Site # Application

Septic Tank Effluent 

Total Nitrogen Quality 

Location (mg/l)

NitrexTM Effluent 

Total Nitrogen 

Quality (mg/l)

Single Family 

Residence (SFR)

Massachusetts Alternative Septic System Test 

Center

Sampling Frequency

Monthly for 30 

months then weekly 

for 12 months

monthly for 21 

months

monthly for 23 

months

BioFilter

NitrexTM Filter

Drainfield Pump

Station

Cluster System Producing Water with Total Nitrogen Average = 3.59 mg/l

Project: Main Street Village

Mashpee, MA

Design Flow: 5,226 gpd

Wastewater Pio Lombardo, P.E. 

Engineer: Lombardo Associates, Inc.

 Boston, MA & Malibu, CA

 617-964-2924

 Pio@LombardoAssociates.com

 www.LombardoAssociates.com

 

The Main Street Village, in Mashpee, Cape Cod, MA, which has 24 housing units and small commercial 

space, was created with a 5,226 gpd design flow, community-sized wastewater treatment system. The 

wastewater system is located in a defined nitrogen sensitive area, a Zone II of a public water supply well. 

Zone II areas are contributing to a water supply well. 

The development is served with Town water and the entire Wastewater System includes a wastewater 

collection system, septic tank, and Recirculating Media Biofilter followed by a NitrexTM Filter to reduce 

effluent total nitrogen prior to discharge to a drainfield. Permit effluent requirements are TN must be < 10 

mg/l. The Wastewater System became operational in March 2006. 

After the start-up period, wastewater effluent 

TN levels have generally been < 3 mg/l. 

Effluent BOD and TSS are typically < 15 mg/l 

and < 5 mg/l, respectively. 

Operations and Maintenance requirements 

consist of permit required monthly visits for 

treatment system performance sampling. 

Daily electrical consumption is approximately 

5 KWHr, or $0.75/day with electric costs of 

$0.15/KWHr. Telephone connection allows 

remote monitoring of flow and notification of 

alarm conditions. No chemicals and no other 

utilities are required.

Mashpee, MA Wastewater System at Completion
The wastewater treatment technology 

demonstrates that decentralized distributed 

wastewater systems can be as effective as 

centralized facilities in achieving the accepted 

limit of technology of TN < 3 mg/l, and is 

another tool for wastewater planners and 

engineers in nitrogen sensitive areas. 

The Mashpee project results are similar to 

independent testing performed in Oregon, 

Montana, and Massachusetts. The NitrexTM

System is an approved technology in a number 

of States, with installations in MA, MD, VA, MT, 

OR, CA and Canada.
 

ACHIEVING TOTAL NITROGEN 3.30 MG/L

Project Bogue Sound Elementary

Location: School & Croatan High School

Newport, NC

Owner: Carteret County Board of Education

Wastewater Lombardo Associates, Inc.

Engineer: Boston, MA & Malibu, CA

www.LombardoAssociates.com

NitrexTM Design Profile:

 Design Wastewater Flow: 12,000 gpd

 NitrexTM Influent Total Nitrogen (TN): 70 mg/l

 Effluent Requirements:

o TN <10 mg/l

o cBOD5 <15 mg/l 

o TSS <15 mg/l

o Fecal Coliform < 200 MPN/100ML

Wastewater Treatment Process: 

Septic Tank  Recirculating Sand Filter  NitrexTM Filter  Recirc. Sand Filter  UV Disinfection  Drainfield

Project Description: 

Lombardo Associates, Inc. (LAI) was retained by the Carteret County Board of Education (CCBoE) to design, permit 

and build a NitrexTM Nitrogen Removal wastewater system serving Croatan High School and Bogue Sound Elementary 

School. The existing wastewater system for the School consisted of three recirculating sand filter (RSF) cells with UV 

disinfection prior to discharge to a drainfield. The LAI design included modifications to the piping of the RSF to optimize 

denitrification and construction of a NitrexTM filter, and using one of the RSFs for polishing. 

The Croatan High School and Bogue Sound Elementary School On-Site Wastewater Treatment System became 

operational in December 2009 and was immediately performing within permit requirements. Performance data is:

Average Effluent Quality:

o TN 3.31 mg/l

o BOD5 < 2 mg/l 

o TSS 8.1 mg/l

o Fecal Coliform 8.8 MPN/100ML

Days from 

Start-up

10-Dec-09 BOD TKN BOD TSS NH3 TKN NO2-N NO3-N Org-N 

Calc.

TN 

Calc.

Fecal 

Coliform

Units mg/l mg/l mg/l mg/l mg/l mg/l mg/l mg/l mg/l mg/l mpn / 100 mL

Permit 15 15 10 10 200

19-Jan-10 40 195 61.6 6.1 8.5 <0.04 1.67 <0.02 0.41 1.65 2.09 <1.0

29-Jan-10 50 240 89.6 2.1 1.3 0.09 0.25 <0.02 0.74 0.16 1 7.0

3-Feb-10 55 210 68.8 <2.0 <1.0 0.00 1.89 0.03 0.67 1.89 2.59 <1.0

12-Feb-10 64 240 134.0 <2.0 <1.0 <0.04 1.12 <0.02 0.61 1.10 1.74 <1.0

19-Feb-10 71 240 149.0 <2.0 <1.0 0.06 0.79 <0.02 0.63 0.73 1.43 2.0

25-Feb-10 77 260 104.0 <2.0 <1.0 <0.04 1.13 <0.02 1.07 1.11 2.21 <1.0

5-Mar-10 85 280 80.4 <2.0 <1.0 <0.04 0.92 0.02 2.02 0.90 2.96 <1.0

12-Mar-10 92 285 115.0 <2.0 <1.0 <0.04 0.90 <0.02 2.12 0.88 3.03 <1.0

5-Apr-10 116 175 70.8 <2.0 <1.0 <0.04 1.86 <0.02 1.40 1.84 3.27 <1.0

24-May-10 165 310 149.0 <2.0 <1.0 <0.04 1.06 <0.02 2.49 1.04 3.56 1.0

22-Jun-10 194 79 107.0 <2.0 2.1 <0.04 1.22 0.03 8.89 1.20 10.14 <1.0

22-Jul-10 224 60 32.0 <2.0 <1.0 0.10 0.96 <0.02 5.39 0.86 6.36 <1.0

30-Aug-10 263 130 121.0 <2.0 4 0.15 0.72 <0.02 2.96 0.57 3.69 127.0

23-Sep-10 287 167 148.0 <2.0 <1.0 0.05 1.05 <0.02 1.10 1.00 2.16 <1.0

6-Oct-10 300 107 86.2 <2.0 <3.1 0.05 1.05 <0.02 1.10 0.62 1.50 <1

30-Nov-10 355 147 138.0 <4.7 42 0.15 5.77 <0.02 1.11 5.62 6.89 2.0

29-Dec-10 384 163 123.0 <2.0 74 <0.04 0.71 <0.02 0.93 0.69 1.65 5.0

31-Mar-11 476 245 132.0 <2.0 <2.7 <0.04 0.42 <0.02 0.33 1.07 1.46 <1

196 106.1 1.5 7.8 0.05 1.32 0.01 1.87 1.27 3.21 8.4

System Effluent

Average

Date

Septic Tank Effluent

Bogue Sound Elementary .

School & Croatan High School .

Newport, NC .
Cape Cod Residential Development Producing Water with Total Nitrogen 2.14 mg/l

Project: Brackett Landing, Eastham, MA

40 unit subdivision

Design Flow: 8,310 gpd

Wastewater Pio Lombardo, P.E.

Engineer: Lombardo Associates, Inc.

Boston, MA & Malibu, CA

617-964-2924

Pio@LombardoAssociates.com

www.LombardoAssociates.com

Lombardo Associates, Inc. (LAI) provided design-build-operate 

services for the wastewater treatment system for the Brackett 

Landing development in the Town of Eastham on Cape Cod, 

MA utilizing the NitrexTM System to achieve nitrogen reduction.

The wastewater system was designed and constructed in accordance with the Town of Eastham Board of Health regulations and the

MADEP Title 5 requirements for Total Nitrogen < 10 mg/l. The System has been installed and operational since September 2007. The 

performance to date is summarized in the following table:

 

Drainfield

Septic Tank

NitrexTM Tank

BioFilter
Producing Water Meeting CA Title 22 Unrestricted Water Reuse Standards

Achieving Total Nitrogen < 2 mg/l and Turbidity <1 NTU

Project: Malibu Village Plaza

Shopping Plaza

Design Flow: 16,000 gpd High Strength

Equivalent to ~40,000 gpd 

Residential Strength Wastewater

System – approximately 200 

homes

Client: Malibu Creek Preservation Co.

c/o Soboroff Partners

Wastewater 

Engineer: Lombardo Associates, Inc.

Malibu, CA & Boston, MA

www.LombardoAssociates.com

Project Description.

The Malibu Village Plaza is a shopping plaza consisting of both retail and commercial businesses. It is located 

in an environmentally sensitive area adjacent to the famous Surfrider Beach in Malibu, California. In 1999 the 

California Regional Water Quality Control Board (CRWQCB) and the City of Malibu conducted groundwater 

and surface water sampling at Malibu Village Plaza and the nearby area and determined that wastewater 

discharge from the Plaza and other properties using conventional septic systems were causing groundwater 

pollution, which adversely impacted Malibu Creek and Malibu Lagoon. 

Lombardo Associates, Inc. (LAI) was retained to engineer a compliant wastewater management system to 

protect Malibu Lagoon and Surfrider Beach. The previous system was a conventional system consisting of 

grease traps, septic tanks and gravel drainfields, which provided insufficient nitrogen and bacteria removal. 

LAI designed a cost-effective wastewater management 

system that employs a septic tank effluent pump 

(STEP) collection system and treatment system 

consisting of the NitrexTM Nitrogen Removal 

Technology, recirculating media pretreatment of septic 

tank effluent, and an ozone – UV disinfection system for 

bacteria removal. Treated effluent is discharged to new

high capacity drainfields. The treatment system was 

designed to treat 16,000 gpd of the high strength 

wastewater (equivalent to ~40,000 gpd of residential 

strength wastewater) as 85% of the flow was from the 

Plaza’s popular restaurants. Discharge is to a drainfield 

at 3 gpd/SF.
Water Quality Data – NitrexTM Wastewater System – Malibu Village Plaza, Malibu, CA

The Malibu Village Plaza Wastewater 

Treatment System has been operational as of 

July 2007. The Plaza’s wastewater treatment 

effluent quality is compliant with permit 

requirements as well as California Title 22 

unrestricted water reuse requirements as 

shown on the following table.

Energy use, 67% of which is for disinfection, 

of the high strength 16,000 gpd facility 

(equivalent to 200 - 250 homes) is 

approximately $7,400 per year (135 kwhr/day 

@$0.15). Operation & Maintenance 

requirements are weekly visits of 2 – 4 hours 

for maintenance and sample collection. An 

additional 125 chemicals are analyzed on a 

monthly basis. All are within permit 

requirements. All contaminants of concern 

are below Detection Limits, typically < 5 ppb.

Avg Max

BOD5 mg/l 30 45 < 5 < 5 < 5 < 5

TSS mg/l 30 45 < 5 < 5 < 5 < 5

Turbidity NTU 10 15 0.7 0.57 0.38 0.45

Total 

Nitrogen mg/l 10 10 2.2 1.70 1.90 1.81

Malibu Village Plaza, Cross Creek Road, Malibu, CA

 Effluent Water Quality Summary and Permit Limits

3 year 

Geometric 

Mean

Constituent Units

Effluent 

Permit Limits

Geometric Mean

2008 2009 2010

p H TSS BOD5 Turbidity Fecal 

Coliform Enterococcus TN

mg/l mg/l NTU MPN/100 ml MPN/100 ml mg/l

Avg 6.5 30 30 10.0 - 24 10.00

Max 8.5 45 45 15.0 200 104 10.00

Avg 2.0 10.0

Max 10.0 10.0

6.6 2.5 2.5 1.16 <2 <1 4.96

6.3 <5 6.9 1.08 1 <1 4.71

6.9 3.23

6.2 9.0 12.0 1.80 2 <1 3.57

6.4 <5 6.0 1.10 <2 <1 4.73

6.2 0.00 0 0 0.00

6.5 <5 <5 5.40 <2 <1 5.61

6.4 <5 <5 1.90 <2 <1 6.72

6.6 7.0 <5 2.60 350 * 1 9.17

6.7 0.00 0 0 0.00

6.8 <5 <5 1.80 350 46 7.88

6.9 2.5 0.35 3 0 5.63

6.9 <5 <5 2.30 <2 <1 7.30

6.8 <5 <5 1.00 <2 <1 6.78

6.9 0.00 0 0 4.29

6.8 0.00 0 0 3.00

6.6 <5 <5 1.00 <2 <1 1.64

6.9 <5 <5 1.85 <2 <1 3.74

7.0 <5 <5 0.34 1 1 3.11

6.7 3.3 2.5 1.03 5 1 2.15

7.0 12.5 <5 10.18 <2 0 8.82

7.0 <5 <5 2.95 23 <1 4.54

7.6 <5 <5 0.75 <2 1 2.01

6.9 2.5 <5 0.37 <2 <1 1.69

6.9 <5 2.5 0.33 <2 <1 1.02

6.9 2.5 2.5 0.28 <2 1 1.41

6.9 <5 5.1 0.60 <2 1 1.01

6.8 2.5 <5 0.55 <2 1 1.21

6.5 <5 14.0 0.28 <2 <1 0.85

7.0 <5 <5 0.30 <2 <1 1.10

6.9 <5 <5 0.58 <2 <1 1.32

6.9 <5 <5 0.29 <2 <1 2.12

7.4 2.5 <5 0.37 <2 <1 1.69

7.4 8.0 <5 0.25 <2 1 1.58

6.7 <5 <5 0.44 <2 <1 1.87

6.6 <5 2.5 0.23 <2 <1 1.94

6.6 <5 <5 0.33 <2 4.0 2.01

6.4 <5 <5 0.28 <2 <1 2.02

6.6 <5 11.0 0.23 <2 <1 3.15

6.6 <5 <5 1.66 <2 <1 1.77

January 2011 6.7 <5 <5 0.40 8 3.0 2.59

February 2011 6.6 <5 <5 0.38 16 6.3 2.91

March 2011 6.8 <5 <5 0.48 16 8.0 1.96

April 2011 6.6 <5 <5 0.35 6 10.6 1.95

May 2011 6.5 <5 <5 0.53 45 47.7 2.73

June 2011 6.7 <5 <5 0.36 61 2.0 2.81

6.7 <5 <5 0.29 72 18.7 4.04

6.9 <5 <5 0.38 31 18.5 2.47

July 2011

August 2011

Oct. 2007

July 2009

Oct. 2008

August 2009

Apr. 2009 **

Sept. 2008

Nov. 2008

Jan. 2009

Feb. 2009

Dec. 2007

Nov. 2007

Apr. 2008

Mar. 2008

Feb. 2009

Jan. 2008

Constituent

Units

Malibu Village 

Plaza Effluent 

Sept. 2007

Title 22 

Unrestricted Reuse 

May 2008

June 2009

July 2008

July 2010

Dec. 2008

Aug. 2008

April 2010

June 2008

March 2010

February 2010

January 2010

Mar. 2009

August 2010

September 2009

May. 2009

May 2010

June 2010

December 2009

November 2009

October 2009

Sept. 2010

Nov. 2010

Oct. 2010

December 2010
 

Harvard, MA 6 bedroom 660 gpd NitrexTM System

BioFilter

Septic 

Tank

NitrexTM Filter

Drip Irrigation

ON-SITE WASTEWATER TREATMENT SYSTEM WITH ALKALINITY CHALLENGES

Project Application Data:

 Location: Harvard, MA

 Site Application: 6 bedroom residential site – 2 houses

 Installation Date: Fall 2006

Wastewater Engineer: Lombardo Associates, Inc.

Boston, MA & Malibu, CA

www.LombardoAssociates.com

Design Profile:

 Design Wastewater Flow = 660 gpd 

 Wastewater Treatment Process: Septic Tank → BioFilter 

→ NitrexTM → UV Disinfection → Drip Irrigation

Project Description:

Due to shallow depth to groundwater and closeness to 

environmentally sensitive wetlands, Lombardo Associates, Inc. 

was retained to engineer an innovative wastewater system for 

the 2 home site. The final design of Septic Tank – BioFilter –

NitrexTM – UV Disinfection – Drip Irrigation was approved by the 

Conservation Commission and had a construction cost savings 

of 40% as compared to the previously bid mound system. Due to 

the extremely high influent nitrogen levels, nitrogen removal were

diminished due to insufficient alkalinity, which LAI solved with an 

automatic alkalinity feed system in summer 2011.

Performance Data:

Harvard, MA

Residential System

DRIP IRRIGATION
 

ON-SITE WASTEWATER TREATMENT SYSTEM 

Project Application Data:

 Location: Scully Estate –

Suffolk County Environmental Center

 Site Application: Islip, NY

 Installation Date: November 2008

Wastewater Lombardo Associates, Inc.

Engineer: Boston, MA & Malibu, CA

www.LombardoAssociates.com

Design Profile:

 Design Wastewater Flow = 1,300 gpd 

 Wastewater Treatment Process: 

Septic Tank → BioFilter → NitrexTM →

Drainfield

Project Description:

The Scully Estate is located on South Bay 

Avenue in Bay Shore, Islip, NY, approximately 

6,500 feet south of Montauk Highway. 

Daily design flow is 1,300 gpd. Because 

of the small flow and the distance and expense 

involved in connecting to the municipal sewer, an onsite treatment and disposal system was implemented.

Nitrogen removal was the critical wastewater issue 

due to the groundwater and ocean water sensitivity. 

For this reason, the Nitrex

TM system was sole source 

selected by Suffolk County.

New features were added to the basic wastewater 

treatment system described above that 

making it LEED compliant. The basic 

treatment process is nitrification followed 

by the NitrexTM denitrification reactor, then 

to the drainfield. 

.

Scully Estate –

Environmental Center

Suffolk County, Islip, NY

08/17/11 73.2 0.13 5.5 92.5% 99.8%

08/24/11 77.1 0.18 7.2 90.7% 99.8%

09/01/11 48.1 0.17 5.6 88.4% 99.8%

TN % 

Removal

NitrexTM 

NO3 

NO3/ % Removal

NO2

TN 

NitrexTM 

Effluent Date

Septic 

Tank 

Effluent

TN 
Residential System Producing Total Nitrogen < 3 mg/l

Project: 1933 Clifton Road

Virginia Beach, VA

Design Flow: 330 gpd

Wastewater 

Engineer: Pio Lombardo,P.E.

Lombardo Associates, Inc.

Malibu, CA & Boston, MA

617-964-2924

Pio@LombardoAssociates.com

www.LombardoAssociates.com 

Lombardo Associates, Inc. (LAI) designed a residential NitrexTM wastewater nitrogen removal system to serve a 

3 bedroom residence in Virginia Beach. The NitrexTM system is virtually maintenance free. The process flow 

diagram is shown below: 

The system was installed in 2008, and is currently achieving TN < 3 mg/l. The water quality data is presented 

below:

Wastewater Flow Primary Treatment/ 

Septic Tank

Recirculating Media 

Filter (RMF) NitrexTM Filter Drip Irrigation

O O O O

NH4

+

 --> NO3

- NO3- --> N2

mg/l mg/l mg/l CFU/100ml

8/21/09 504 1.87 18.0 15.0 40

11/4/09 579 1.61 16.0 5.3 <1

7/21/10 838 2.83 3.0 4.0 <1

2.10 12.3 8.1 13.7

BOD

Average

TSS Fecal 

Coliform

NitrexTM

TN 

(calc) Date

Days 

from 

Startup

 
NitrexTM 

Effluent

TN

mg/l

May-07 2,068 3.17

1.10

0.96

0.20

Sep-07 299 2.05

Average 514 1.50

Jun-07 268

Jul-07 703

Date

Avg. 

Monthly 

Flow 

(gpd)

RESIDENTIAL SYSTEM PRODUCING TOTAL NITROGEN < 3 mg/l

Project: Landing at Water’s Edge

Chincoteague, VA

Design Flow: 3,900 gpd

Wastewater 

Engineer: Pio Lombardo,P.E.

Lombardo Associates, Inc.

Malibu, CA & Boston, MA

617-964-2924

Pio@LombardoAssociates.com

www.LombardoAssociates.com

LAI designed the NitrexTM component of the 

wastewater treatment and disposal system for the 

seasonally used Landings at Water’s Edge site in 

Chincoteague, VA to reduce total nitrogen to less 

than 10 mg/l in the effluent after pretreatment by a 

recirculating peat filter aerobic treatment system. 

The system is designed for sanitary sewage from a 

residential development with approximately 15 units. 

The system has been operational since February 

2007 and effluent total nitrogen has been <3 mg/l.

The NitrexTM system is virtually maintenance free. 

The water quality data is presented below:
Cost Competitive NitrexTM Technology Systems on $ / lb Nitrogen Removed – Residential Systems

TN < 3 mg/l

Project: Calvert County, MD

3 Sites

Design Flow: 450 gpd

Wastewater 

Engineer: Pio Lombardo, P.E.

Lombardo Associates, Inc.

Boston, MA & Malibu, CA

617-964-2924

Pio@LombardoAssociates.com

www.LombardoAssociates.com

The Board of County Commissioners of Calvert 

County, MD, awarded Lombardo Associates, Inc. 

(LAI) three project sites for the installation of the 

NitrexTM Technology Nitrogen Removal Systems. 

The systems were installed in 2008, and are currently achieving TN < 3 mg/l.

% Denitrification Rate = 93.3%

 

PROJECT DESCRIPTION ––

Calvert County,, Maryland

Site #1 – Before Construction Site #1 – During Construction

Site #2 – Before Construction Site #2 – During Construction

PreTreatment 

Unit

Septic Tank

NitrexTM
System Performance:

Site #1 F&N

TN (mg/l)

Avg. after 

Start-up1 1.40

Site #2 R

TN (mg/l)

Avg. after 

Start-up2 2.39

Site #3 A

TN (mg/l)

Avg. after 

Start-up2 2.36

3 After May. 2009 excluding 9/16/09

2 After Feb. 2009 

1 After Sept. 2009

Calvert County, MD 

NitrexTM Systems Data

Date

Date

Date

Site #3 – Before Construction Site #3 – After Construction
Nitrate Nitrogen < 0.1 -0.6 mg/l

Total Phosphorus < 0.1 mg/l

Total Perchlorate < 0.2 ug/l 

Project: Permeable Reactive Barrier (PRB)

Passive Groundwater Treatment

Nitrogen Removal

Wastewater 

Engineer: Pio Lombardo, P.E.

Lombardo Associates, Inc.

Boston, MA & Malibu, CA

617-964-2924

Pio@LombardoAssociates.com

www.LombardoAssociates.com

Site 1 – Nitrogen Removal – Cape Cod, MA

As part of a Cooperative Institute for Coastal and 

Estuarine Environmental Technology (CICEET) funded 

demonstrated project, the Woods Hole Marine Biological 

Lab (MBL) retained Lombardo Associates, Inc. (LAI) for 

installation of the patented NitrexTM groundwater nitrogen 

removal technology at two locations on Cape Cod, MA in 

the Waquoit Bay watershed. The above photograph 

illustrates the dramatic water quality improvement with 

the installation.

Performance

Site

Influent 

Nitrate – N 

(mg/l)

Effluent 

Nitrate – N 

(mg/l)

Waquoit Bay, MA 1.74 0.007

Childs River, MA 7.19 0.568

Passive Groundwater Treatment 

for Nitrogen, Phosphorus & Perchlorate Removal

Installation of PRB
Cross Section. NitrexTM PRB

Site 2 – Nitrogen Removal – Southern New England

Two NitrexTM PRBs were installed in a Rhode Island coastal watershed. Upstream and downstream concentrations 

of nitrate, ammonia, and dissolved organic nitrogen in the groundwater were monitored over two annual cycles. The 

dissolved inorganic nitrogen (DIN) levels are presented below.

Rhode Island 

Sites

Influent DIN 

(mg/l)

Effluent DIN 

(mg/l)

Coastal Site #1 3.9 0.2

Coastal Site #2 3.7 0.1

DIN = Dissolved Inorganic Nitrogen = Ammonium + Nitrate + Nitrite

Site 3 – Perchlorate and Nitrogen Removal – Ontario, Canada

Ontario, 

Canada Site

Nitrate - N 

(mg/l)

Perchlorate 

(ug/l)

Influent 50 50

Effluent <0.1 <0.2

Site 4 – Phosphorus Removal –Massachusetts Site

Massachusetts 

Site

Influent 

Phosphorus 

(mg/l)

Effluent 

Phosphorus 

(mg/l)

Site #1 1.7 0.1

Site
Treating Groundwater to Produce Nitrate – N Levels < 0.1 mg/l 

Project: Waquoit Bay, MA 

 Permeable Reactive Barrier (PRB) 

 Passive Groundwater Treatment 

 Nitrogen Removal 

Wastewater 

Engineer: Pio Lombardo, P.E. 

Lombardo Associates, Inc. 

 Malibu, CA & Boston, MA 

 617-964-2924 

 Pio@LombardoAssociates.com 

 www.LombardoAssociates.com

 

Waquoit Bay is located in the towns of Falmouth and 

Mashpee on the south side of Cape Cod. It is part of the 

Waquoit Bay National Estuarine Research Reserve 

(WBNERR), which has about 3,000 acres of bays, 

ponds and uplands. As part of a Cooperative Institute 

for Coastal and Estuarine Environmental Technology 

(CICEET) funded demonstrated project, the Woods Hole 

Marine Biological Lab (MBL) retained Lombardo 

Associates, Inc. (LAI) for installation of the patented 

NitrexTM groundwater nitrogen removal technology at 

two locations in the Waquoit Bay watershed. 

The two installations constructed in summer 2005 are: 

• Childs River 

• Waquoit Bay Reserve Property – 

149 Waquoit Highway, East Falmouth, MA 

Performance. 

Site Influent 

Nitrate – N 

(mg/l) 

Effluent 

Nitrate – N (mg/l)

Waquoit Bay 1.74 0.007 

Childs River 7.19 0.568 

PROJECT DESCRIPTION – 

Waquoit Bay, Ma – 

Passive Groundwater Treatment for

Nitrogen Removal

Wa uoit Bay Test Sites

Childs River PRB

NitrexTM PRB 

Below 
Waquoit

Bay

Algae

Algae

No Algae 

Nitrex

(In

P

C

NitrexTM Permeable Reac

For Nitrogen Removal Waquoit Bay National EstReserve (WBNERR), Falm

Evaluated by the Woods Hole Marine Biological Laboratory (MBL) 
6 

Nitrate at Waquoit Bay – Data Collected bHole MBL

Groundwater Flow

Note log scale of Y axis

No Barrier

With Barrier

Groundwater Quality at Waquoit Bay - Data Collected by Woods Hole MBL
7 May 2007 

To Whom it May Concern: 

I write in support of Mr. Pio Lombardo and Lombardo Associates, Inc proposal for 

design and construction of permeable reactive barriers. I first met Mr. Lombardo when I was 

serving as the Town of Falmouth, MA planning board representative to the Ashumet Nitrogen 

Plume Offset Committee. This committee was established to propose ways to use $8.5 

million pledged to the Town of Falmouth by the Air Force Center for Environmental 

Excellence (AFCEE) to reduce nitrogen loading in three East Falmouth coastal ponds 

(Bournes, Green and Great Ponds) contaminated by a sewage plume emanating from the 

Massachusetts Military Reservation. The Town, in conjunction with the Committee, drafted a 

Request for Proposal (RFP) and Lombardo and Associates was selected to prepare 

recommendations for remediation of the nitrogen-overloading problem in these ponds. They 

proposed a novel design for constructed wetlands that minimized the land area required by 

concentrating treatment in modules containing NitrexTM, their proprietary medium fostering 

N-removal. 

I was impressed with the originality of their proposal, which also included the option of 

using of a NitrexTM

 permeable reactive barrier along the coast to intercept and remove nitrates 

from groundwater entering the ponds. Mr. Lombardo made several excellent points in their 

presentation to the Committee including: (1) that such barriers left intact the existing septic 

system infrastructure, which provides effective primary and secondary treatment; (2) that the 

barriers operate passively and incur no annual operating and maintenance expense and (3) that 

the barriers are far more cost effective to build ($/lb N removed) than centralized sewage 

treatment facilities capable of tertiary treatment. At the time (approximately five years ago), 

this approach was so new and innovative that the committee was unwilling to endorse it. 

Simply put, it was untested in coastal environments. As a research scientist working on the 

response of coastal and estuarine ecosystems to nitrogen inputs, this piqued my curiosity. 

Subsequently, I approached Mr. Lombardo about developing a research proposal for the 

Cooperative Institute for Coastal and Estuarine Environmental Technology, a program

sponsored by NOAA, in order to construct two small test barriers in Waquoit Bay that could 

be studied to assess their performance and evaluate the viability of this approach. We were 

successful in obtaining funding and Lombardo and Associates was responsible for the design 

and construction of these test systems, which we installed in August of 2004. Lombardo 

fulfilled all the obligations of their contract with us on time and under budget. We have a 

good working relationship with Mr. Lombardo and his colleague and collaborator, Dr. Will 

Robertson, at the University of Waterloo in Ontario, Canada, the patent holder for this 

technology. 
Letter of Reference – Lombardo Associates 

Page 2 

We have been studying these systems now for two years and have obtained quite a bit of 

interesting data. I believe this approach has great promise, though in my view further 

research is needed in coastal settings subject to tides in order to optimize the performance of 

the barriers. In particular, we have observed that the barrier can become inundated with 

seawater during storms and spring tides. Seawater intrusion into the NitrexTM can affect its 

performance and results in high rates of sulfate reduction that could shorten the barrier life. It 

is also critically important the barriers be installed deep enough to intercept the majority of

the nitrate plume in groundwater. Despite these concerns we believe the barrier approach is 

worth pursuing, especially in non-tidal or micro-tidal environments protected from storms

where it is unlikely that seawater will penetrate the barrier matrix and displace groundwater. 

Sincerely, 

Kenneth H. Foreman, Ph.D. 
Figure A: Process Flow Diagram 

 

 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: 

3⁄4 40 miles of septic tank effluent collection system (50% gravity & 50% pressure)

3⁄4 900,000 gallons per day (gpd) Treatment Process of: 

 recirculating sand filters, 

 constructed bulrush wetlands for nitrogen removal, 

 constructed peat wetland for phosphorus removal 

 UV disinfection 

3⁄4 Ultimate disposal through an off-shore, submerged aquatic vegetation wetland 

` 

PPRROOJJEECCTT DDEESSCCRRIIPPTTIIOONN –– 

MMAAYYOO PPEENNIINNSSUULLAA,, MMDD
Integrated Phase Implementation: 

The Mayo Peninsula Wastewater Collection System was completed in stages, with the 

Collection 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 (right) presents the treatment 

performance. 

 Figures 1-5 (below) illustrate the 

process demonstrated in the process 

flow diagram of Figure A. 

 

Figure 1B: Typical Small Pump Station 

Porous Pavement 

Figure 1A: Typical House Septic Tank – 

 Effluent Collection 

Septic Tank Cover 

Table 1: Historical Performance 

Septic Treatment Reduction 

Tank Plant % of 

Influent Effluent Influent

BOD 85.8 4.4 94.8%

(mg/l)

TSS 55.7 2.1 96.3%

(mg/l)

TN 33.7 7.4 78.0%

(mg/l)

Average Data from 01/93 to 08/05
Figure 1C: Typical Large Pump Station 

Figure 3: Bulrush Wetland 

 

 

Figure 2: Aerial View of Communal 

Wastewater Treatment System 

Bulrush Wetlands 

Recirculating 

Sand Filter (RSF) 

Peat Wetlands 
Figure 4: Peat Wetland During Operation

 

Figure 5: Aerial View of Constructed Offshore 

Wetland

submerged aquatic 

vegetation wetlands
Malibu La Paz – City Hall Village Green

No-Discharge NitrexTM Wastewater Treatment System – 1

st of its kind in California – unanimously approved

Project: La Paz Development

Malibu, CA

Code Design Flow: 37,120 gpd

Wastewater Lombardo Associates, Inc.

Engineer: Malibu, CA & Boston, MA

www.LombardoAssociates.com

Client Mr. Don Schmitz, AICP

Reference: Schmitz & Associates, Inc.

DonS@schmitzandassociates.net

The La Paz Development, located in an environmentally sensitive area adjacent to the famous Malibu Surfrider 

Beach, consists of eleven (11) commercial buildings with two 175 seats restaurants and a municipal facility.

The wastewater management plan includes 

a CA Department of Public Health approved 

Title 22 Disinfected Tertiary Recycled Water 

Treatment system that will beneficially reuse 

all recycled water for in-building non-potable 

water use purposes and landscape irrigation 

and will have No Discharge to the ground or 

surface waters. An effluent storage tank is 

provided for seasonal periods when recycled 

water generation is greater than reuse 

requirements.

No Discharge is achieved by:

1. In-Building Bathroom Non-Potable Water Reuse Purposes 

2. Landscape Irrigation

The integrated wastewater-recycled water-irrigation system will achieve a 57% reduction of water use. 

The LaPaz Wastewater Management Engineering 

Plan was unanimously approved by the Los Angeles 

Regional Water Quality Control Board (LARWQCB), 

which has issued a WRR/WDR permit for the project 

- the first such system approved in California. The 

California Department of Public Health (DPH) has 

determined that the LaPaz wastewater reuse project 

is compliant with CA Title 22 Disinfected Tertiary 

Treatment Standards. The City of Malibu has 

approved the LaPaz Wastewater Management –

Water Reuse System.

La Paz Development, Malibu, CA - No Discharge Wastewater Reuse System 

Landscape Irrigation Potable 

Water Supply

WWTP Recycled 

Water 

Reuse for 

Bathroom and/or 

other Non 

Potable Use