There was an interesting study performed several years ago, commissioned by FDOT and undetaken by the University of South Florida (USF). The study was chaired by Dr. Kranc, PE;
OPTIMUM PLACEMENT OF UTILITIES WITHIN FDOT R/W .
This study took into consideration all of the separation requirements and considered both existing and "virgin" utility corridors. As I recall, Dr. Kranc and his group developed an Excel spreadsheet that would create an optimal placement matrix based upon the type, size and number of utilities being placed and also took into consideration issues such as, future access needs and maintenance.
There is a link to this study on the FDOT website;
OPTIMUM PLACEMENT OF UTILITIES WITHIN FDOT R/W ------------------------------
Gregory Jeffries B.S., M.ASCE
Regional SUE Manager - Texas
McKim & Creed
Certified Utility Contractor
UESI - Utility Risk Management Division
Utility Investigation Committee Member
------------------------------
Original Message:
Sent: 10-03-2017 10:12
From: David Dillmann
Subject: Utility Layout - Separation Requirements for Various Utilities
Scott,
The Texas Commission on Environmental Quality (TCEQ) is the governing agency that sets standards for water distribution systems. The standard separation distances for water and wastewater is no closer than 9 ft. in all directions measured from the outside surfaces. There are exceptions to have at minimum 4 ft. horizontal and 2 ft. vertical separation (drinking water above) if pressure rated pipe is used and other requirements are followed, See 30 TAC Rule 290.44 for more information. I hunted around on the TCEQ website for more information on salt water lines and how they are classified, but could not find anything specific to your application as fire protection. One thing that comes to mind is you may have to have specially labelled fire hydrants indicating non-potable water, but I am not sure.
I suggest you go to the water section of the TCEQ website. There is an email address for questions. I have submitted questions before for unique situations I've encountered. They are a bit slow but do provide comprehensive answers.
------------------------------
David Dillmann P.E., M.ASCE
Snr Project Manager
Atkins North America, Inc.
Carrollton TX
Original Message:
Sent: 10-02-2017 09:46
From: James Bednarczyk
Subject: Utility Layout - Separation Requirements for Various Utilities
Scott,
Check with your local Department of Health (DOH) or agency responsible for drinking water in your area. We use 10' separation horizontal and 18" vertical for sewers. And where the distances cannot be met we require concrete encapsulation.
We follow 10 State Standards and our DOH requirements for our specs. http://10statesstandards.com/waterrev2012.pd
Good Luck,
Jim
------------------------------
James Bednarczyk Aff.M.ASCE
Junior Engineer
Mohawk Valley Water Authority
Original Message:
Sent: 09-26-2017 10:42
From: Scott Mason
Subject: Utility Layout - Separation Requirements for Various Utilities
Howdy,
First time ever post hopefully in the right section? I am looking for a direction to find standards regarding my question.
Project location is at a Coastal Texas Port Facility.
Designing a proposed potable water main, as well as, a saltwater main for fire protection. Saltwater to be pressurized from a pumping station in emergency situations then to be flushed after use. Question I have is separation distances for these two mains, as well as, can they be buried in the same trench. I have a stretch where they parallel and looking at options. Both lines to be constructed of PVC. Any help would be appreciated. If any more input is needed from me, feel free to ask. Young engineer and have not ran into this situation before.
Thank you!
------------------------------
Scott Mason P.E., M.ASCE
Lead Project Engineer
G&W Engineers, Inc.
Port Lavaca TX
------------------------------