"The discoveries of the last few years have radically altered our methods of treatment of sewage, both within and without the building. We have through these discoveries, learned why it is that sewage must be quickly removed from our neighborhood instead of being allowed to remain in cesspools... The science of bacteriology has become to the sanitary engineer, in a certain sense, the most interesting and important of all sciences, though dealing with the most infinitesimal of all known living organisms. Without its aid he has been groping about in darkness."
Plumbing and Household Sanitation, pp 49 John Pickering Putnam, 1911
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The Journal of the American Leather Chemists Association, Vol XI, 1916
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Referring to the same subject, in 1874, Henry Gibbons, Jr., M. D., in his official report as Health Officer, says: "Washerwoman's Bay, Mission Bay and Mission Creek are constantly augmenting in filthiness. The difficulties in the way of remedying this evil seems almost insurmountable, although effort has been made, and some work has been done in Mission Bay. It is a happy circumstance for our people that this bay is not to the windward of the city. If anyone doubt it let him ride over Brannan or Fourth Street Bridge on a warm day when the tide is low. In regard to Mission Creek much might be said. Few seem to know its extent or its filthiness. From away beyond Eighteenth street, where it originates in a pond, down past Sixteenth street, at its intersection with Harrison—the very recollection of which locality by a person who has visited it, is almost sufficient to, sicken—to the outlet in Mission bay and even beyond, it smells to heaven with a loudness and persistence that the strongest nostrils may not withstand, and the disinfectants of a metropolis could not remove. If by any means it were possible to draw sufficient public attention to these serious evils to cause their speedy removal, I would feel that a better work in the interest of the public health had been accomplished than all else combined."
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"Our magic carpet to new hopes, new dreams, and a better way of life"
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The custom of attempting to flush the defective sewers of San Francisco in the late summer and early autumn months has given rise to the idea that all sewers need flushing. It is made very apparent by the sense of smell that they need something.
Report upon a system of sewerage for the city and county of San Francisco, 1899, p 36
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...the entire lack of system which characterizes the existing sewers of this City has given a very exaggerated importance to the idea of flushing sewers with salt water. The stenches from our sewers in August and September of each year are caused, not altogether by a need of flushing, but by irregularities and defects in grades and sizes which permit accumulations of sewage, which gradually putrefy. Hence, after the full volume of water from a three or four-inch hose has been poured under pressure into the storm water inlets, for hours the stench remains. No reasonable volume of water will flush a sewer having the defects of construction explained in the Reports of 1892-93.
Report upon a system of sewerage for the city and county of San Francisco, 1899, p 36
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Where it falls upon built-up and paved districts the first wash contains dust, manure, and much organic matter, which at times makes such water almost as foul as sewage. Report upon a system of sewerage for the city and county of San Francisco, 1899, p 103
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In the British registrar-general's returns for 1868 it was stated that in twenty-two years no less than 23,689 women in England and Wales had died of puerperal septic diseases. In the reports of the Rotunda Hospital, Dublin, the largest maternity hospital in the United Kingdom, we ascertain that of 30,023 women delivered during the ten years 1894- 1903 there was only a mortality of 21 due to sepsis, a ratio of 0.066%, while the registrar-general's returns for England and Ireland for the period have a ratio for sepsis' of 0.216%.
Encyclopaedia Britannica, 1911, 1922
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A freeway, Tilton warned, "is a device which can make or break the city. It can liberate or contribute to congestion. It can cut the city into unrelated parts, or bind it together. It can destroy values, or create new ones. The State cannot soundly develop its urban freeway plans without attention to the planning problems of the city itself." Tilton criticized the state for a narrow approach that considered merely "the assembly and interpretation of traffic data," the "engineering problem of designing bridges and tunnels," and practice of making plans "without adequate consideration of local problems and without reference to local planning bodies." He emphasized the need "to plan future improvements which will bring maximum benefits to the business interests and people" insisting that "This first freeway ought... to be definitely related to the city's plans for mass transportation as well as for the movement of private vehicles. Failure to provide for transit service on the Freeway will result in an un- manageable deluge of private automobiles in the already congested areas of the city."
William Issel, The Pacific Historical Review, Vol. 68, No. 4 (Nov., 1999), pp. 611-646
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Bicycles are inherently unstable. They attain a measure of stability only through the angular momentum of the turning wheels when traveling fast enough. Being held up by only two wheels, the bicyclist is constantly busy avoiding falls and is particularly vulnerable to side winds, truck slipstreams, unevenness in the road surface, slippery spots on turns and when being forced to use very low speeds.
Bicycles do not have crumple zones like motor vehicles
TRAFFIC ENGINEERING HANDBOOK 6TH EDITION Institute of Transportation Engineers, 6.A
Urban freeways may be depressed, elevated, at-grade, or a combination of each. A design speed of at least 60 mph (100 km/hr.) is recommended, although a design speed of 50 mph (80 km/hr.) is used on rare occasions.
TRAFFIC ENGINEERING HANDBOOK 6TH EDITION Institute of Transportation Engineers, 7.C
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Empirical observations of traffic streams in the earliest days of highway systems showed that relationships existed among traffic speed, flow and density. The most obvious was the relationship between speed and density. As travel lanes became more crowded, it was apparent that speeds tended to drop, ultimately reaching a crawl when vehicle spacing approached jam density.
TRAFFIC ENGINEERING HANDBOOK 6TH EDITION Institute of Transportation Engineers, 4.B
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Barlow's Disease, Proceedings of the Royal Society of Medicine
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ASCE 7-10 Changes to Ch. 13 Seismic Design Requirements for Nonstructural Components
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should you happen to ask any one of our student’ s what they know about the formative history of the concept, let alone the names and backgrounds of the responsible engineers, you’ ll quickly find that their corresponding knowledge ranges from bare to nil. In large measure, the technical roots for activated sludge have largely been ignored within our current texts and classes, such that most students likely share a common misconception that activated sludge has forever been the preeminent option for wastewater purification.
...
Porter’ s two works alone, respectively written in 1917 and 1921, are certainly indicative of the explosive interest which this technology first drew. Barely six years after the idea had originally been published, the associated literature had already grown in number to nearly 800 articles.
THE GENESIS AND EVOLUTION OF ACTIVATED SLUDGE TECHNOLOGY James E. Alleman
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The following listing provides a chronological summary of these facilities: Salford, 1914, Davyhulme, 1915; Worcester, 1916; Sheffield, 1916; 1917; Stamford, 1917; Tunstall, 1920; Sheffield, 1920; Davyhulme, 1921; and Bury, 1921. In the United States, progression of the activated sludge process moved with similarly amazing speed. Edward Bartow, a Professor at the University of Illinois, visited Fowler’ s group in Manchester in August of 1914 and subsequently began his own bench-and pilot-scale experiments along the lines established by Fowler’ s group. Within a period of several months, numerous other American researchers initiated similar studies, including those by Hammond, Hendrick, Hurd, Frank, Mohlman, Hatton, and Pearse. (Maring, 1927; Pearse, 1938; Metcalf & Eddy, 1916; Babbitt, 1926) Full-scale U.S. installations began to appear to 1916, and by 1927 there were nearly ten full-scale systems spread throughout the country, including: San Marcos (TX), 1916; Milwaukee (WI), 1916; Cleveland (OH), 1916; Houston (TX), 1917 & 1918 (2 each); Des Plaines (IL), 1922; Calumet (IN), 1922; Milwaukee (WI), 1925; and Indianapolis (IN), 1927
THE GENESIS AND EVOLUTION OF ACTIVATED SLUDGE TECHNOLOGY James E. Alleman
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Science, after having long groped about, now knows that the most fecundating and the most efficacious of fertilizers is human manure. The Chinese, let us confess it to our shame, knew it before us. Not a Chinese peasant--it is Eckberg who says this,--goes to town without bringing back with him, at the two extremities of his bamboo pole, two full buckets of what we designate as filth. Thanks to human dung, the earth in China is still as young as in the days of Abraham. Chinese wheat yields a hundred fold of the seed. There is no guano comparable in fertility with the detritus of a capital. A great city is the most mighty of dung-makers. Certain success would attend the experiment of employing the city to manure the plain. If our gold is manure, our manure, on the other hand, is gold.
What is done with this golden manure? It is swept into the abyss.
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The sewage of the Steiner street sewer, and to some extent that of the Pierce street, is being utilized during the spring and summer months for the irrigation of Chinese vegetable gardens located near these streets north of Chestnut street.
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Now, I had been taught in school that scurvy had been conquered in 1747... But here was a Royal Navy surgeon in 1911 apparently ignorant of what caused the disease, or how to cure it. Somehow a highly-trained group of scientists at the start of the 20th century knew less about scurvy than the average sea captain in Napoleonic times.
...in the second half of the nineteenth century, the cure for scurvy was lost. The story of how this happened is a striking demonstration of the problem of induction, and how progress in one field of study can lead to unintended steps backward in another.
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No comprehensive sewer and drainage system for San Faancisco has ever been made the guide in the matter of sewer construction. We are at this late date charged with devising one. But even if one had been designed, modifications of detail due to the extension of streets, changes of street grades and other unforeseen conditions would have to be made from time to time.
The duty of preparing the plans and specifications for sewers required from time to time falls to the City and County Surveyor. He prescribes gradients and exercises control over line and grade. The supervision of construction, however falls to the Superintendent of Streets, whose department is required to compel strict compliance with specifications. •
Sewers are constructed either by public or private contract. In case of sewer construction by public contract all proceedings, the calling of bids, the awarding of the contract and the execution of the work are in direct charge of of the city officers.
In the case of sewer construction by private contract, the planning and supervising of the work are in charge of city officials, but the authorities are not concerned in the award of the contract, except that before any private sewer construction can be undertaken, a permit for the work must be secured from the Superintendent of Streets.
Whether done by public or private contract, the work is to conform to requirements prescribed by ordinance and specifications, and it is the duty of the Superintendent of Streets to know that there are no deviations from such requirements. Whether constructed by public or private contract, all sewers in streets that have been finally accepted as improved streets must be maintained and kept in repair at public expense.
The original cost of sewers falls upon the property benefited in proportion to amount of benefit and in proportion to street frontage. In the case of all local sewers, the first cost falls on the property fronting upon the streets sewered.
Although it would appear that by reason of being required to furnish plans and specifications for each sewer constructed, the City and County Surveyor is interested in. knowing that the plans are carried out and that the specifications are complied with, it seems to have become a well established custom for that office to participate in ordinary sewer work only to the extent of giving the contractor line and grade for his work, and of certifying to the fact that the sewer at its manholes, when completed, has a depth below street grade as named in the certificate then issued.
The City and County Surveyor charges fees prescribed by ordinance for his services, and as he personally bears all the expenses of surveys it is natural to suppose that he will endeavor to keep his expenses as low as possible. It is not surprising, then, that when information in his office justifies such a course, he issues diagrams to the contractor with instructions to conform to street curbs for line and grade, or to place the sewer at "10 feet below street grades if connections will allow," furnishing reference points in the latter case from which a skillful contractor establishes his own grade line.
This system of issuing indefinite, unintelligible instructions to contractors, and for the guidance of Superintendents of Streets,prevails to-day, but it is not of recent origin; it has been in vogue throughout many administrations and has led to innumerable defects in construction that will entail great expense to correct.
To the engineering profession the explanation is due in this connection that the office of City and County Surveyor is an elective one, that party politics can be relied on. in San Francisco no more than elsewhere to consider qualifications for office a prerequisite to election, and that the responsibility for all sewer work has fallen partly upon the Surveyor and partly upon the Superintendent of Streets. Without such explanation it would indeed be difficult to account for the persistent lack of endeavor to effect a reform. The system of municipal administration is at fault, more than the individual officers, and better results will be difficult of attainment until the construction of sewers receives intelligent and honest engineering direction and supervision. In this connection Hon. William Alvord, Mayor of San Francisco, in his address when retiring from office, says :* "If the offices of Superintendent of Streets and Surveyor were united, and the Surveyor allowed the same executive aids which the Superintendent now has, receiving only a salary for his duties, it would be possible to prosecute such works as the opening, grading, paving and sewering of streets according to a comprehensive scientific method and at greatly reduced cost to property holders, who are now assessed doubly and trebly by reason of the many mistakes made in detached improvements. The want of able scientific direction in this department is more especially evident in the matter of sewerage. At present short, isolated sewers are often constructed, without outlet and without reference to ultimate connection with the mains forming part of a well studied, comprehensive system, because such a system has not been commenced or planned."
So lax has been the system of administration in this direction that it is safe to say that Superintendents of Streets have, more frequently than even the several City and County Surveyors, been permitted to prescribe the character and size of sewers to be constructed. The work of sewer construction has moreover been carried forward piecemeal, generally a block or a crossing, rarely a few blocks at a time, according to the temper and inclination of the property holders.
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