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from concept to completion

Civil Engineering

From complex site development to advanced septic design, DAE delivers civil engineering solutions tailored to the unique environmental and regulatory challenges of eastern Long Island. Our team combines decades of regional experience with advanced 3D modeling and permitting expertise to move projects from concept through construction.

DAE SIGNATURE SERVICE

I/A Septic Design

DAE is recognized as a regional leader in I/A septic design, delivering advanced wastewater systems that meet stringent local regulations and adapt to the unique conditions of each site.

Take a deep dive into our I/A Septic Design:

 

Capabilities
Technical Details
What It's Like Working with DAE
Featured Projects

Proven expertise in all aspects of civil engineering and site design.

Innovative/Alternative
Septic System Design

Stormwater Management
& Landscape Drainage Design

Stormwater Pollution
Prevention Plan (SWPPP)

Grading & Earthwork

Subdivision Development

Preliminary Septic Analysis

Innovative/Alternative
Septic System Design

Since the inception of innovative and alternative onsite wastewater treatment system (I/A OWTS)requirements in eastern Long Island, DAE has been at the forefront of designing and permitting these advanced septic systems. Our team works across residential and commercial sites, developing solutions that reduce nitrogen levels and propect water quality-even in areas with limited space and environmental constraints. With deep experience navigating the Suffolk County Health Department's permitting process, we help move projects forward efficiently and in full compliance.

 

We provide:

Custom I/A septic system design and permitting, tailored to the site's unique conditions-such as high groundwater, tight setbacks, or environmentally sensitive locations.

 

Septic system layouts and calculations that meet SCHD requirements, including denitrification system sizing based on bedroom count.

 

End-to-end permitting support with SCHD, from digital submittals to final approvals.

 

Solutions for difficult sites, including those with wells, wetlands, poor-draining soils, or restrictive easements.

 

● Flow rate evalutions for commercial uses, ensuring systems are sized appropriately for restaurants, medical offices, and other higher-demand buildings.

 

Feasability reviews to determine if an exising system can be reused or upgraded.

 

Inspection and certification services to support property sales and regulatory compliance.

 

Pre-design coordination, including test holes, utility markouts, and survey reviews to streamline permitting and design.

Stormwater Management & Landscape Drainage Design

DAE develops thoughtful, code-compliant stormwater management plans that support permitting and protect site integrity. We evaluate how proposed improvements will impact runoff and drainage, and design systems that integrate with site utilities to mitigate flood risk, prevent erosion, and reduce the potential for downstream impacts. Our goal is to deliver coordinated, permit-ready solutions that perform reliably over the long term.

 

We provide:

Stormwater calculations and analysis to meet local code requirements for new site improvements.

 

Stormwater management plans depicting drainage features such as surface drains, downspout connections, and storage volumes.

 

Coordination of stormwater systems with proposed water and electric service lines.

 

Complete, submittal-ready materials required for permit applications.

Stormwater Pollution Prevention Plan (SWPPP)

DAE prepares Stormwater Pollution Prevention Plans (SWPPP) and provides the documentation required for coverage under the State Pollutant Discharge Elimination System (SPDES) General Permit for Stormwater Discharges from Construction Activity. These plans are required for construction projects that disturb one acre or more of soil and ensure compliance with New York State Department of Environmental Conservation (NYSDEC) requirements.

We create site-specific stormwater strategies that address both construction-phase erosion control and long-term drainage needs. Our team brings extensive experience across eastern Long Island, including work on sites near sensitive bodies of water and in areas with heightened protection requirements.

For erosion and sediment controls, we provide:

 

Comprehensive SWPPP plans tailored to site conditions, architectural drawings, and survey data.

 

Initial site inspections to confirm existing conditions and support accurate stormwater design.

 

Temporary erosion and sediment control designs that meet NYSDEC and MS4 requirements.

 

Full digital submittals to NYSDEC, including all documentation required for SPDES permit coverage.

 

Ongoing SWPPP inspections and reporting during construction to support continued compliance.

 

For post-construction stormwater controls, we provide:

 

Permanent drainage system design for sites near waterbodies and other environmentally sensitive areas.

 

Pre- and post-construction runoff modeling and drainage calculations based on NYSDEC standards.

 

Site drainage plans and supporting documentation prepared as part of the local building permit application.

 

System design and calculations in accordance with the NYS Stormwater Management Design Manual.

 

Coordination with architects and design teams to integrate stormwater systems into overall site development.

Grading & Earthwork

DAE provides precise cut and fill analysis to estimate earthwork quantities and support efficient site grading. Our analysis identifies where soil needs to be removed or added, helping control construction costs, minimize waste, and keep projects on schedule.

 

We provide:

Site plans showing cut and fill areas to include in permit applications.

 

Cut and fill analysis with net import/export summaries based on current and proposed site conditions.

 

Coordination of earthwork volume calculations with proposed architectural floor plans.

 

Grading plans developed to meet project requirements and adapt to site-specific conditions.

Subdivision Development

Securing subdivision approval in Suffolk County requires a deep understanding of Department of Health Services (SCDHS) regulations and the expertise to manage complex, multi-phase applications. DAE brings extensive experience guiding projects from initial plans and engineering certifications through to final approval. We collaborate closely with clients, consultants, and SCDHS throughout the process to keep approvals moving forward without unnecessary delays.

 

We provide:

● Review of subdivision plans and engineering certification to meet SCDHS requirements.

 

● Preparation and coordination of all subdivision submissions, from initial applications to follow-up filings.

 

● Research of county, town, and municipal records to support approvals.

 

● Coordination with surveyors, attorneys, and environmental consultants.

 

● Oversight of septic inspections, test holes, mark outs, and other required field services.

 

● Representation at SCDHS Board of Review hearings when variances are needed.

 

● Completion of all SCDHS applications and required documentation, including lot layouts and septic details.

 

Ongoing communication with SCDHS and related parties to help ensure timely approvals and keep projects on schedule.

Preliminary septic analysis

DAE provides early septic evaluations to help clients understand the likelihood of obtaining Suffolk County Health Department (SCHD) approval for a property. This upfront analysis offers insight into septic system feasibility and supports informed decisions during the early stages of design and planning.

● Site research and data collection to support septic system planning.

 

● Public records requests to gather historical property information from SCHD and local building departments.

 

● Preliminary estimates of wastewater flow to guide site design and building layouts.

 

● Verification of public water availability and review of nearby wells using public records and DAE’s project experience.

 

● Observations on general soil conditions, informed by local expertise.

 

● Identification of potential challenges that could affect SCHD permit approval.

 

● Draft layout options for septic systems based on available site plans or surveys.

 

● Clear recommendations for next steps to move the project toward permitting.

 

Our Approach

At DAE, our civil engineering services are built on a collaborative, detail-driven process that balances innovative problem-solving with a deep understanding of the unique challenges across the Hamptons. Our work is tailored to each site’s technical demands and each client’s vision, ensuring every solution is practical, efficient, and compliant.

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3D Modeling & Analysis

We use advanced 3D modeling and analysis to streamline design decisions and provide clear visualizations for clients, design teams, and regulatory agencies. Our civil team leverages 3D cut and fill analysis to optimize grading plans, calculate material quantities, and reduce site disturbance—especially important in areas with strict environmental oversight. For properties with complex access or elevation challenges, we develop detailed 3D renderings of driveway layouts, ensuring smooth functionality and aesthetic integration with the site.

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Collaboration & Communication

We believe successful projects are built on open communication and strong partnerships. From the initial concept through permitting and construction, we coordinate closely with surveyors, architects, contractors, and local authorities to keep projects moving forward. Our long-standing relationships with many of East End’s most active surveyors allows us to coordinate updates quickly and efficiently behind the scenes. Whether we’re resolving zoning issues or coordinating utility design, our collaborative approach helps resolve challenges early—keeping projects on track and momentum through the approval process.

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Innovative Approach

We specialize in finding innovative solutions for complex sites throughout the Hamptons. Our team has extensive experience navigating projects impacted by wetlands, high groundwater tables, tight setbacks, and low elevation lots. Whether the challenge is limited space for sanitary systems or strict environmental regulations, we develop creative, code-compliant strategies that balance site constraints with project goals.

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Experience

With more than 1,000 septic system designs completed across the Hamptons, DAE brings a wealth of hands-on experience to every project. We understand the intricacies of working in sensitive environments and the expectations of local agencies. Our civil engineering team is skilled in managing everything from straightforward site plans to multi-phase developments, delivering successful outcomes with a focus on quality, efficiency, and long-term performance.

Civil Engineering Resources

Access expert insights and practical tools to support your civil engineering project. From I/A-OWTS requirements and septic system calculators to managing poor-draining soils, these resources address common challenges of site development and wastewater design on complex sites throughout eastern Long Island.

Deep Excavations – Impact of Poor
Draining Soils on Long Island Septic
Design (I/A-OWTS)

Septic System
Calculator

Long Island Septic Systems –
Shift to I/A-OWTS

Most Common Civil Engineering Questions

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