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Seminar/Webinar, Friday, August 18, 2023
8:30 am – 4:00 pm EDT

Presented by Steven Trinkaus

Site Investigation for Low Impact Development Practices

  • Deep test holes – soil limitations
  • Infiltration testing
  • Types of infiltration tests; which ones are most accurate to use
  • Is percolation testing useful or not

Environmental Conditions

  • Land slope
  • Potentially restrictive soil conditions

How to Design LID Infiltrative Practices for Variable Site Conditions

  • Bioretention systems
  • Permeable pavement systems
  • Infiltration trenches
  • Dry swales

Designing Bioretention Systems for Peak Rate Attenuation Without Affecting Water Quality Aspects

  • The importance of designing practices with all required components
  • Pollutant loading analysis
    • What are they and why are they necessary?
    • Sources for non-point source pollutants
    • Sources for pollutant removal efficiencies
    • Equations to be used to calculate pollutant loads and pollutant removal rates
    • Standalone treatment systems and systems in series
    • Using dry and wet systems to enhance removal rates of pollutants
    • Determining pollutant loads removal
    • Efficiencies for systems in series

Case Studies – The Good, The Bad and The Ugly

Webinar Instructions

All attendees must log-on through their own email – attendees may not watch together if they wish to earn continuing education credit. HalfMoon Education Inc. must be able to prove attendance if either the attendee or HalfMoon Education Inc. is audited.

Certificates of completion can be downloaded in PDF form upon passing a short quiz. A link to the quiz will be sent to each qualifying attendee immediately after the webinar. The certificate can be downloaded from the Results page of the quiz upon scoring 80% or higher.

Webinars are presented via GoToWebinar, an easy-to-use application that can be run on most systems and tablets. Instructions and login information will be provided in an email sent close to the date of the webinar. It is highly recommended that you download, install and test the application before the webinar begins by clicking on the link in the email.

GoToWebinar App requirements:
Windows 7 – 10 or Mac OSX Mavericks (10.9) – macOS Catalina (10.15)

Web Browser:
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Internet Explorer v11 (or later) with Flash enabled

Internet connection: Minimum of 1Mbps       Hardware: 2GB RAM or more

For more information, visit the Support section at


Professional Engineers
6.0 PDHs

6.0 HSW CE Hours

Landscape Architects
6.0 HSW CE Hours

International Code Council
0.6 CEUs (Sitework)

Floodplain Managers

Continuing Education Credit Information 

This seminar and online webinar are open to the public and are designed to qualify for 6.0 PDHs for professional engineers, 6.0 HSW continuing education hours for licensed architects, and 6.0 HSW continuing education hours for landscape architects in all states that allow this learning method. Please refer to specific state rules to determine eligibility.

HalfMoon Education is an approved continuing education sponsor for engineers in Florida (Provider No. 0004647), Indiana (License No. CE21700059), Maryland, New Jersey (Approval No. 24GP00000700) and North Carolina (S-0130). HalfMoon Education is deemed an approved continuing education sponsor for New York engineers and architects via its registration with the American Institute of Architects Continuing Education System (Regulations of the Commissioner §68.14(i)(2) and §69.6(i)(2)). Other states do not preapprove continuing education providers or courses.

The American Institute of Architects Continuing Education System has approved this course for 6.0 HSW LUs (Sponsor No. J885). Only full participation is reportable to the AIA/CES.

The Landscape Architecture Continuing Education System has approved this course for 6.0 HSW PDHs. Only full participation is reportable to the LA CES.

The International Code Council has approved this event for .6 CEUs in the specialty area of Sitework (Preferred Provider No. 1232).

This course has been approved by the Association of State Floodplain Managers for 6.0 CECs for floodplain managers.

Attendance will be monitored, and attendance certificates will be available after the course for those who attend the entire course and score a minimum 80% on the quiz that follows the course (multiple attempts allowed).

On-Demand Credits

The preceding credit information only applies to the live presentation. This course in an on-demand format may not be eligible for the same credits as the live presentation; please consult your licensing board(s) to ensure that a structured, asynchronous learning format is appropriate. The following pre-approvals may be available for the on-demand format upon request:

6.0 HSW LUs (AIA) 
6.0 HSW PDHs (LA CES) 


Steven Trinkaus, PE

Principal at Trinkaus Engineering, LLC, in Southbury, CT

Mr. Trinkaus is an internationally recognized expert in the field of low impact development, having presented at many ASCE/EWRI international conferences and many other regional conferences and workshops on LID and water quality issues. He has been an invited presenter and consultant in Taiwan, China, and South Korea. He has also presented on Sustainable Stormwater at the University of St. Andrews in Scotland. Mr. Trinkaus has written LID design manuals for the Towns of Tolland, Plainville, Harwinton, East Granby, and Morris, Connecticut. He has designed many types of LID treatment systems for a variety of residential and commercial applications. Mr. Trinkaus is chair of the EWRI LID Guidance Document Task Committee and primary author of the Committee’s national guidance document on adopting LID standards. Mr. Trinkaus is a licensed professional engineer in Connecticut and Maryland. He received a Bachelor of Science degree in Forest Management in 1980 from the University of New Hampshire. He has more than 38 years of experience in the land development field, more than 19 years of experience designing low impact development treatment systems, and six years of experience writing LID regulations and design manuals.

AIA Info

AIA Provider Statement:

HalfMoon Education Inc. is a registered provider of AIA-approved continuing education under Provider Number J885. All registered AIA/CES Providers must comply with the AIA Standards for Continuing Education Programs. Any questions or concerns about this provider of learning program may be sent to AIA/CES ( or (800) AIA 3837, Option 3).

This learning program is registered with AIA/CES for continuing professional education. As such, it does not include content that may be deemed or construed to be an approval or endorsement by the AIA of any material of construction or any method or manner of handling, using, distributing, or dealing in any material or product.

AIA continuing education credit has been reviewed and approved by AIA/CES. Learners must complete the entire learning program to receive continuing education credit. AIA continuing education Learning Units earned upon completion of this course will be reported to AIA/CES for AIA members. Certificates of Completion for both AIA members and non-AIA members are available upon request.

Course Title: Designing Low Impact Development Practices for Water Quality

Delivery Method: Live Online

Course Description: This six-hour course will demonstrate how to design Low Impact Development (LID) practices with the goal of preserving water quality. The course begins with a focus on site investigation and testing before providing and analyzing LID practices and strategies meant for various site conditions. The course will also focus on pollutant loading analysis; identifying sources of pollutants, calculating loads, and increasing removal rates.

Learning Objectives:

Learning Objective 1:
Learners will be able to adopt site investigation strategies necessary to develop Low Impact Development practices, including the use of deep test holes, infiltration testing and percolation testing, for determining soil properties and limitations.

Learning Objective 2:
Learners will be able to recognize environmental conditions that may affect Low Impact Development practices such as slopes and potentially restrictive soil conditions.

Learning Objective 3:
Learners will be able to utilize Low Impact Development practices for various site conditions, including bioretention systems, permeable pavement systems, infiltration trenches and dry swales.

Learning Objective 4:
Learners will be able to identify sources of pollution, calculate pollutant loads and removal rates, and use wet and dry systems to enhance removal rates.

LUs: 6.0                                                                                             LU Type: LU|HSWs.

Prerequisites: Familiarity with stormwater management issues and practices

Advance Preparation: None

Program Level: Intermediate

Course Expiration Date: 06/09/2026

Complaint Resolution Policy:

Complaints regarding this course can be emailed to or by calling (715) 835-5900. A HalfMoon Education representative will respond within 72 hours to resolve the complaint, which will include, but not limited to, access to another CE activity at no or reduced cost or a full or partial refund. Each instance will be resolved on a case-by-case situation.

On-Demand Price: $319.00

Save $20 per person when registering 3 or more people.

Each registration includes a PDF copy of a manual prepared by the seminar speaker.