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Civil Engineering

Expertise in all aspects of civil engineering and site design

  • I/A Septic Design
  • Drainage Design
  • SWPPP’s
  • Grading & Earthwork
  • Subdivisions
  • I/A Septic Design

I/A Septic Design

DAE has managed the design of septic systems and the required application to the Suffolk County Health Department since the first town required it on the East End of Long Island. We have extensive experience in both residential and commercial design and permitting.

  • I/A Septic Design (Residential and Commercial)
  • Suffolk County Health Department Septic Permits
  • Experts in difficult site conditions including high groundwater, wells, wetlands, driveway covenants, poor draining soils, etc.
  • Commercial flow rate assessments
  • Septic inspections and certifications

civil engineering septic i/a owts installation
  • Drainage Design

Drainage Design

Drainage plans are required by most municipalities as part of a building permit application or by NYSDEC/Town Wetlands for an environmental permit.

  • Drainage plans for municipal, DEC and wetlands board permits
  • High groundwater drainage techniques including shallow retention systems, gravel beds, french drains
  • Areaway and lightwell draining

civil engineering drainage construction
  • SWPPP’s


In NYS, before commencing construction activity, the owner/operator of a construction project that will involve soil disturbance of one or more acres must obtain coverage under the State Pollutant Discharge Elimination System (SPEDES) General Permit for Stormwater Discharges from Construction Activity. DAE can help identify when a Stormwater Pollution Prevention Plan (SWPPP) is required and help guide you through the entire process.

  • Stormwater Pollution Prevention Plan preparation
  • SWPPP management through MS4 acceptance and DEC approval
  • SWPPP Inspections

civil engineering stormwater pollution prevention plan swppp
  • Grading & Earthwork

Grading & Earthwork

Site conditions in coastal areas can present a myriad of challenges. We offer a full range of site design services to integrate your plan into the existing landscape.

  • Site grading plans
  • Cut & Fill Analysis
  • Driveway and road plans
  • Retaining wall designs

civil engineering site design grading plan
  • Subdivisions


With vacant land becoming scarcer and the amount of zoning regulations increasing, getting a subdivision approved can be a daunting task. We have the experience and network of partners to get projects approved faster.

  • Subdivision planning and management
  • Subdivision plan review and certification
  • Subdivision applications with Suffolk County Health Department
  • Lot Line Modification applications with the Suffolk County Health Department

civil engineering subdivision planning

Civil Capabilities

3D Modeling & Analysis

We utilize Civil 3D to create 3D site plans to allow for better accuracy and coordination throughout the entire site.

Collaboration & Communication

Our engineers work closely with architects, owners, and designers from the creation of individualized design criteria to the project's customized engineering approach to ensure a practical design inline with our clients vision.

Innovative Approach

We have experience integrating various non-traditional materials and analysis processes to accommodate the most challenging site conditions in an environmentally conscious manner.


Our team has been designing and permitting I/A-OWTS systems since they’ve been required on the East End of Long Island. This experience and staying on top of the latest technology allows us to better serve our clients throughout the process.

What Our Clients Say

We work with a range of clients including architects, builders, owners, and consultants.

“DiLandro Andrews Engineering was indispensable in the civil engineering of an onsite wastewater treatment system. This septic system is located in an environmentally sensitive bay front location of our beach club. As a result, a state of the art system was needed to replace a 55 year old cesspool. As a further constraint, the system is located under an active parking lot where space is a premium. DiLandro Andrews worked tirelessly through multiple evolutions in requirements by the County Department of Health and our Club. Turnarounds and responses were executed on a same-day basis. In the end, they delivered a perfect solution. We feel confident in saying that less talented engineers would have failed to deliver a solution given the regulatory and practical demands of the site. We strongly recommend DiLandro Andrews for any commercial onsite water treatment system project in Suffolk County. You will need professional talent and perseverance, and they provide it every step of the way.”

La Ronde Beach Club

Westhampton Beach, New York

“I worked with Paul DiLandro on a septic design and install. He designed the new system that was required by Southampton. Everyone in the office was great, very responsive and helpful. He was also very helpful in dealing with Suffolk County. Would definitely use them again!”


East Hampton, New York