David was born in Newark NJ to Alphons and Irene O'Konski. He was their beloved third son and grew up with three brothers in Mountainside NJ and at Lake Mohawk NJ. David was energetic, imaginative, and inquisitive. He had a ready smile, was fun to be around, and made friends easily.  He liked science and tech topics. He was a talented musician and natural showman, and he loved engaging and entertaining people.  David was a good student and enjoyed antagonizing his K-12 nuns, teachers, and priests (consistently but gently) and they assigned him detention sessions (consistently but gently).  They appreciated his intellect, talents, and wit, and many remained life-long David friends and fans.

David earned a Bachelor of Science degree in Industrial Hygiene from Quinnipiac College in 1979. He earned his CIH and CCHP, and he established a professional career in Washington DC, including positions with the Smithsonian Institution, SAIC, and other consulting firms. He earned an MBA from USC.  He and the love of his life, Jana Helene Ambrose, were married in 1986. Within three months they founded Applied Environmental Inc, a pioneering business in an important emerging field.  It was and continues to be their shared life project.  Her business acumen, his charisma, and their shared competence and professionalism promised and delivered solid business success and professional fulfillment.

Most importantly, David's and Jana's mutual devotion underpinned thirty-five years of successful, warm, and fun family life, of which both were justifiably proud. They shared and enjoyed travel together, especially to New England and the Canadian Maritime Provinces. In their idyllic home in Hamilton VA, David and Jana enjoyed shared hobbies and interests including horseback riding, piano and bass guitar, shooting sports, Lionel trains, and a menagerie of horses and rescued dogs, cats, and other "critters." Family and friends visited frequently, were warmly welcomed, and unfailingly well-fed by Jana and Chef David. And Showman David fostered long musical evenings, including impromptu jazz and rock jams with relatives, string recitals with nieces, and Christmas sing-alongs with everybody.

David was active in his church and several professional societies, and he continually expanded his success in a range of pursuits.  He always had a smile and a laugh, and was known for insatiable curiosity, and never-ending willingness to do, share, and help. His marriage and family, Catholic faith and Polish heritage, and his friends and profession animated his life. David worked successfully at being a good husband, brother, uncle, mentor, and friend. His was a life well-lived.

He is survived by his beloved spouse Jana, her three brothers and their families, his three brothers and their families, nephews, nieces, grand-nieces, grand-nephews, and countless close friends.  All will remember David as a good husband, brother, uncle, friend, top-of-his-game consultant, leader, and steady guiding light. He was a good man. He taught us by example to project integrity, to help each other, and to recognize and fully enjoy every life moment.  His sharp intelligence, sound judgment, and professional accomplishments left their mark. We will remember and cherish David, his infectious good humor, his smile, and the ever-present twinkle in his eye.

David's family and friends will celebrate a Mass of Christian Burial at Saint Francis de Sales Catholic Church in Purcellville VA on Friday January 22 at 11 AM, preceded by a viewing at the Church at 10:00, and followed by burial services at Hillsboro Cemetery at noon. (The Mass is livestream viewable via https://vimeo.com/stfrancisdesales .)

In lieu of flowers please consider a donation to Loudoun Hunger Relief, Hamilton Volunteer Fire Department and Rescue Squad, Loudoun County Animal Shelter, or a charity of your choice.