October 6, 2014 

Office of Ground Water and Drinking Water (MC 4607M) 

Standards and Risk Management Division 

U.S. Environmental Protection Agency 

1200 Pennsylvania Avenue NW. 

Washington, DC 20460; 

RE: Distribution System Storage Facility Inspection and Cleaning 

All, 

Although I would like to have participated in the public meeting and webinar that will be held on 

October 15, 2014 from 12:00 p.m. to 5:00 p.m., Eastern time, I will be traveling that entire day 

and I am unable to change my travel plans. 

However, I would like to hereby request that the items presented in this correspondence, as well 

as the documents and photos included with this correspondence, be reviewed, discussed, and 

considered by EPA during their decision process of this issue. 

As a brief introduction, I started to inspect potable water storage tanks in 1976 with engineering 

firms, then performed sanitary surveys on hundreds of tanks as a health official charged with The 

Enforcement Of The Safe Drinking Water Act. In 1982 I started my own inspection firm 

whereby I have personally inspected more than 4,000 tanks since 1982 and I personally inspect 

about 150 tanks each and every year. 

Attached with this correspondence is additional information about me and my company. 

Also attached are a few representative inspection photos from 20 tanks chosen completely 

randomly from the hundred plus tanks we inspected this year already, which very clearly 

demonstrate that, even after 8 to 31 years being in service after the tank was either installed or 

last cleaned, there are only traces to maybe 1⁄2” of dirt on the bottom. Also note that there is 

virtually no dirt on the sidewalls, even in the tanks that are corroded and require a recoat. There 

are only traces, to less than 1⁄2”, of dirt on the bottom of at least 95%, and more likely, 99% 

of all the tanks we inspect each year. 

Please note that the inspection photos are from various types of tank construction such as welded 

steel, epoxy coated bolted steel, glass lined bolted steel, prestressed concrete, hypalon lined 

reservoir with floating cover, etc. I can provide you with inspection photos from hundreds of 

additional tanks that show you the same thing, there is no need to clean the tanks every 5 years. 

ROV And Drained Potable Water Storage Tank, NFPA Fire Water Tank, & Pipeline Inspections
Conrady Consultant Services 

Office of Ground Water and Drinking Water (MC 4607M) 

U.S. Environmental Protection Agency 

October 6, 2014 

Page 2 of 2 

Please consider the following: 

1. I fully agree that potable water tanks should be required to be completely inspected 

internally and externally every 5 years but not cleaned. The 5 year inspection would 

determine if there is enough dirt or any biofilm that the tank should be cleaned. The 

only way to adequately clean a tank is to drain and pressure wash it. ROV or diver 

cleaning only removes the bottom silt and does not remove the sidewall dirt or any biofilm 

if existing. 

2. Draining any water tank to be cleaned is a considerable expense and inconvenience to the 

utility, especially if they only have one tank. Even with multiple tanks on the system, 

draining one of their tanks involves adjusting the entire system to operate without the 

flows and pressure provided by this tank during normal operation of the system for the 

time that this tank is out of service. There normally is a loss of available fire protection 

water when this tank is out of service. Then there are the hundreds of thousands of utility 

water systems with only 1 tank. Taking their one and only tank out of service, especially 

just to have it cleaned, is an absolute nightmare. DO NOT TAKE MY WORD ON THIS. 

SURVEY YOUR UTILITIES. No utility water system anywhere, at any time, wants to 

take a tank out of service. Even worse, just to be required to take a tank out of service 

every 5 years for an unnecessary cleaning is unjustifiable. 

3. Potable water tanks should be required to be inspected by a professional firm specializing 

in tank inspections, and not by unqualified firms or persons with no experience and 

education whatsoever about tank construction, recoating, inspection, or repair. There are 

currently no minimum requirements whatsoever by any federal regulatory agency for tank 

inspection companies, and only a few states place any kind of requirements for the 

individuals or firms that inspect tanks in their jurisdiction. No joking, at this point in 

time, a high school child, postman, plumber, car mechanic, real estate agent, etc., can 

purchase an ROV for $3,000.00 and start inspecting tanks tomorrow. Although they are 

completely clueless about what to look for, and what they are looking at, they are hired if 

their inspection price is the lowest bid, and then utility and water consumers and their 

engineer have to deal with an inaccurate inspection. Not recoating/repairing a tank when 

it needs it results in the eventual repair/recoat or even replacement being much more 

expensive than it would have been. Even worse, an inspection that results in the utility 

recoating/repairing a tank now when there was no need to this to occur until another 10 to 

20 years is a complete waste of the utility funds. 

4. The dirt on the tank bottom comes from the water lines supplying the tank. Requiring 

annual or semiannual flushing of the water lines makes much more sense than requiring 

the cleaning of the tank. Utilities with effective line flushing programs have very little, if 

any, dirt on their tank bottoms. Flushing the water lines prevents the dirt from reaching 

the tank as well as reducing or eliminating dirty water complaints. 
Conrady Consultant Services 

Office of Ground Water and Drinking Water (MC 4607M) 

U.S. Environmental Protection Agency 

October 6, 2014 

Page 3 of 3 

Please consider the following: 

5. Interior protective coatings on steel tanks, and the interior caulking on glass lined bolted 

steel tanks, deteriorates and fails to the extent that repair/replacement becomes necessary 

in time periods of as little as 10 years or as long as 25 years. Five year inspections 

determine when these are necessary. Whenever a repair/recoat is required, the tank is 

drained, and the contractor cleans the tank as part of the repair/recoat. Please refer to the 

representative photos. 

6. In tanks that previously had water stratification, the installation of either passive or active 

water mixing systems in tanks has virtually eliminated the formation of biofilm on the 

tank walls due to the mixing of the fresh chlorinated water with the older non-circulated 

water. On tanks with adequate circulation and no water stratification, we have not 

observed formation of biofilm. In either of these cases, there is no need to clean the tank. 

7. What our inspections have determined is that there is considerable risk of tank water 

contamination of birds and animals/varmints/snakes being able to enter the tank and that 

this occurs much more frequently than previously thought. Water system personnel do 

not routinely, if ever, climb their tanks to observe if the overflow pipe screens or vent 

screens are still effective and not damaged. Health officials doing yearly sanitary surveys 

are not adequately trained, and do not have the appropriate climbing safety equipment, to 

climb to the top of a taller, or elevated water tank to determine the condition of these 

screens or if the roof hatches are closed and sealed. This is a major problem and 

requires regulatory action to prevent this. We have inspected tanks then traveled to a 

neighboring utility to have lunch because we would not drink their water. 

In conclusion, we believe that the EPA should require tank inspections to occur at intervals that 

should not exceed 5 years but not that the tank be cleaned every 5 years. Do not require utilities 

undergo unnecessary, expensive, and very inconvenient and time consuming tank cleaning 

unless the 5 year inspection determines that cleaning should be done. EPA should require semiannual or annual water line flushing which prevents any buildup of silt in the tanks and virtually 

eliminates the need for cleaning. 

Instead of being so concerned about cleaning the insignificant dirt from the very rare tanks that 

actually need to be cleaned, EPA should focus on preventing water contamination by eliminating 

access to the tank interior by birds, animals, etc. Want some photos? 

Sincerely, 

John R. Conrady, P.E.