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To whom it may concern, What is overland flow requirements for new deveopments? The standard specifications for a city in California require an overland flow requirement when designing grading and storm water requirements for new developments such as subdivisions. Is overland flow...

To whom it may concern, I need to do an stormrwater runoff analysis of a 100 acre industrial site. The site currently discharges directly to waters of the US; however, the local water board is coming down on them and the facility needs to hold and or treat the runoff water. What method would...

To whom it may concern, Is there ever a problem with a smaller sewer gravity main dumping into a larger sewer trunk line below the HGL of the larger sewer trunk main. In other words, if the smaller sewer main is surcharged above its pipe crown from flow from the main trunk line will there be...

To someone who can help. Typically if a IDF curve is provided for a site is it typically not necessary to calculate time of concentration since the IDF curve gives intensities? Or is time of concentration still necessary? Thanks,

Could someone please tell me which is more efficient, submersible pumps or vertical line shaft turbine pumps and why. I was told one is better than the other; however, I thought they both can turn impellers inside bowls and there would be no difference. The only difference I thought is that a...

Could someone please advise me why designed highway profiles always follow a second degree equation (ax^2+bx+c). I have always been curious about this. Thanks, Civil G

Could someone please tell me what a saddle manhole is and why are they used in place of regular manholes? Thanks, CivilG

I am designing a new water distribution system for a new subdivision. The water lines are 6" and 8" diameter C-900. Due to the profile and grade breaks in the road profile, my water lines will have to follow the same profile with slight ups and downs as the grade changes. Question: Is it...

To all, Could someone please tell me what the difference is if any between a flange coupling adapter and a flange by MJ adapter is? Please tell me what each would be used for. Thanks, Civil G

I am new to the water world. Is the only difference between a restrained mechanical joint and a regular mechanical joint the addition of a grip ring such as a mega lug that has set screws that screw down onto the pipe. Also does a concrete kicker make a regular mechanical joint a restrained...

I have a question concerning the Hazen Williams equation for determining Head Loss. Is there any way to figure minor losses such as the losses that occur at valves and fittings? Or does Hazen Williams only calculate major losses in pipes? Thanks,

To all, Could someone please tell me what the difference is between C-900 and C-905 other than size. I am told that C-905 has a smaller safety factor designed into it since the C-905 is designed for larger transmissions mains where there is less surge pressure spikes. thanks,

I am an engineer in California and need to find a rule for testing and acceptance of the joints of a 48" RCP sewer pipe that I have designed. ASTM C924 (April 2004) says that 48" and larger pipes will be accepted by individual joint testing and not pressurizing the entire run. Does anyone know...

I am working on a water project in California and need to know if bronze service saddles can be used on ductile iron pipe or is there a issue with dissimilar metals causing corrosion. Is there a note on this in AWWA? Thanks, Civil G

What is the purpose of a eccentric manhole cone versus a concentric manhole cone? When do you use either. Do you use a eccentric cone because steps need to be bolted into a vertical surface for climbing in and out? Thanks,

I agree with what you posted; however, when an entire watershed is contributing to an point of interest (i.e. drainage inlet) wouldn't the intensity of a given storm event be the same as the intensity derived from the time of concentration from the most distant point in the watershed?

Could someone please tell me why some engineers and agencies use and specify a minimum time of concentration when using the rational method? Does it have something to do with intensities or time of concentrations of past rainfall events not being accurate at short concentration times? I notice...

Could someone please tell me why highway vertical curve alignments follow a quadratic equation? (ax^2+bx+c=y). Is it because this curve is the most smoothest between to tangent lines? I build a lot of highways but am not sure why this is the common convention by my DOT and engineers. Thanks,

I have a question about gps vertical accuracy. I am an inspector on major highway projects in California. I work with alot of surveyors as they set grade stakes. Typically the surveyors will use GPS for setting the stakes and hubs in the horizontal position but follow up with a level or total...

Could someone please tell me the difference between Jack and Boring and microtunneling. Also is one method better for beneath the water table than the other. Is one more precise for alignment and grade control? How to they dispose of the soil when the tunnel is being dug? Which is cheaper...