Current recommendations are summarized on environmental protection, and reviews in some detail those areas most urgently in need of further research and development. Among these areas are the improvement and simplification of surveillance and assessment techniques (especially for such nuclides as Krypton-85 and tritium) development of methods for finger-printing radionuclides released from specific installation or through specific applications, formulation of standards for waste control, preparation of guides or standards for use in the planning and execution of operations involving major radionuclide releases, and the development of environmental counter-measures in the event of significant or unforeseen releases.

The relative percentage of combustible material remaining in the residue from municipal incinerators can be used as an indicator of the effectiveness of such a unit. Several methods of analyzing this fraction can be used, but the Loss on Ignition at 750○ for one hour is a simple test, requiring minimal skills of the operator. The test can be used to measure the reduction in the combustible fraction, sometimes referred to as burnout. The relationship of burnout to the Loss of Ignition of residue and raw refuse is presented.

A set of nonlinear partial differential equations with dimensionless variables, for filtration of dilute unisized suspension in water through homogeneous sand beds under constant rates of vertically downward flow, is presented. The equations describe the space-time variation of suspension concentration and specific deposit in a filter medium. An expression for dimensionless filter coefficient relating all physical variables of filtration is obtained by dimensional analysis. Solutions of the equations were obtained with the aid of a digital computer using the finite difference method. The analytically determined suspension concentrations at different time intervals and depths of bed agreed adequately with the experimental values. An equation relating head loss per unit depth and specific deposit within the filter bed is derived and the validity of the proposed equation is verified with the experimental head loss data.

The Delaware River Basin encompasses many clean streams and a major pollution problem in the 85 mile long Delaware estuary. Water quality management concepts applied in the development of regional water quality standards included protection of clean streams, abatement of polluted waters, a minimum required degree of wastewater treatment, and the equitable apportionment of stream assimilative capacity. The Delaware River Basin Commission adopted water quality standards and regulations setting forth water uses to be protected, water quality criteria necessary to protect water uses, effluent quality requirements, and allocations of stream assimilative capacity.

The main emphasis in research studies of liquid radioactive management has been: (1) Demonstration of the effectiveness and economic feasibility of conversion to solids of the higher level liquid wastes; (2) conversion to solids in place and in the ground for low and intermediate level waste; and (3) determination of the fate and hazard of the minor quantities of liquid waste discharged to the environment. For gaseous wastes, the emphasis has been on the removal of the various forms of iodine in the off-gas systems and the development of new methods for noble gas removal. For solid waste disposal, better containment has been sought, and private burial operations have been transferred to commercial burial grounds. The management of radioactive wastes has not proven to be a deterent to a nuclear power economy. The major problems remaining are methods of the removal of noble gases and tritium, development of methods of fuel reprocessing, and understanding of the movements of radionuclides in the environment.

Engineering elements essential to the financing, construction, operation and maintenance of sewerage facilities for use by two or more parties are outlined. Contract terms, conditions and clauses in successful use which include engineering basis for jointly sharing the capacities of sewage collection and treatment facilities, and for jointly sharing of capital and annual operating and maintenance costs are covered. Definitions of engineering terms, regulations pertaining to conditions of wastewaters, both domestic and industrial, acceptable from the party being served, as well as how and when payments are made according to actual contracts in effect are given. The importance of scheduling payments to meet commitments is presented. Examples are cited to indicate how engineering factors and needs of a specific location affect the patterns of a contract. The fact that no lawyer should endeavor to write a contract without engineering consultation and that no engineer should write a contract without legal advice is emphasized.

A concentric cylinder apparatus utilizing an electronic particle size analyzer was used to study the coagulation of finely divided silica particles by alum and FeCl₃ and the coagulation of natural color in water by alum. The unit was capable of indicating the agglomerate size distribution directly, from which information on the rate and extent of coagulation and on the strength and settling characteristics of the floc could be determined. Study variables included pH, coagulant dose, silica or color concentration, mixing rate, and the method of coagulant addition. The experimental results were used to formulate a theory of coagulation for the alum-silica system in which coagulation is thought to involve chemical interaction between the silica surface and Al(OH)₃ precipitate to form small agglomerates called unit flocs. Further coagulation, according to the theory, would require chemical interaction between unit flocs, and is based largely on the collision dynamics of the system.

California has established standards for reclaimed waste water used for crop and landscape irrigation and recreational impoundments. Insofar as possible the standards avoid the use of specific quality parameters in order to minimize monitoring requirements which would be burdensome to small operations. The major exception is that, where a disinfected reclaimed waste water is necessary, daily coliform bacteria analyses are required. This requirement was one of four major controversial points which are presented. Other major points raised in the development of standards are specification of operational controls and practices in the production and use of reclaimed waste water, and quality requirements for the various uses.

Data obtained with a pilot-plant scale, dissolved-air ion flotation unit, with feed chromium concentrations from 25 mg per 1 to 100 mg per 1 (as Cr₂O₇) and feed rates from 8 gal per hr to 32 gal per hr, are subjected to multiple regression analysis. Accurate equations relate the fractional flotation of dichromate and of surfactant and the enrichment ratio for dichromate to five independent variables. At the optimum values of the independent variables—polymer dosage 3.2% of the feed dichromate concentration, molar surfactant to dichromate feed ratio of 2.1, 170% recycle, 85 min detention time, and dichromate feed concentration of 100 mg per 1—the chemical operating cost, including surfactant recovery, is 67 cents per pound of chromium. The prime advantage of the process is the concentration of the chromium in a small liquid volume, less than 1% of the feed.

The mathematical formulation of tracer dispersion curves of settling tanks has been investigated. As a result, the coefficient of eddy diffusion characterizing the settling zone can be obtained either analytically or by the graphical solution of the formulation. The available relations in the literature describing the effect of eddy diffusion on the settling properties of suspended particles can then be used to predict the corresponding particle removal. A similarity rule for modeling sedimentation tanks is deduced from the verified relations. It calls for preserving two ratios proposed as Hazen and Camp numbers in both the model and the prototype systems. The proposed similarity rule approaches Reynolds' law as the coefficient of eddy diffusion decreases, approaching the kinematic viscosity of the fluid.

Factors of specific concern in the design and operating characteristics of nuclear plants to Federal, State, and local health agencies include physical and demographic site characteristics, potential air, water, land, and food contamination, land use, zoning, and exposure pathways. These factors must be considered to assure that the operation of one or more reactors at the selected site will not adversely affect the population and environment surrounding the plant. Research programs at operating power reactors are being coordinated to determine the methodology and analytical techniques required for an optimum surveillance program. The nuclear facility operator in cooperation with the State health agency should have a planned and rehearsed emergency plan which can be placed into effect to minimize adverse consequences in the event of an accident.

A computer simulation program has been developed for the purpose of evaluating the dynamic operational characteristics of refuse collection crews employed on a constant length workday basis. The constant length workday simulation program was used to evaluate the overall performance of the collection crews, the quality and unit costs of the service provided to the service area (dollars/ton, dollars/service/week, percentage on-time collection), under different operational policies. Policies related to the use of overtime, the use of a relay driver for hauling the last load of the day, the average quantity of refuse assigned per crew, and the assigned total length of workday, were evaluated for a hypothetical service area. Unit cost expressed as dollars/service/week is preferable to unit cost expressed as dollars/ton in assessing the cost of refuse collection.

Analog computer solutions of activated sludge design equations are presented for constant, shock, and periodic feed input conditions. System responses of the aerated lagoon, extended aeration, and separate sludge wasting activated sludge systems to these different inputs are analyzed with the following conclusions: (1) The analog computer can be used to solve nonlinear differential equations for both steady-state and transient solutions; (2) operational changes caused by different plant influents, e.g., shock and periodic loads, and response comparisons of different activated sludge systems to such inputs can be determined using the analog computer; and (3) research is necessary to confirm the ability of present design expressions to describe transient changes in actual treatment plants.

This investigation deals with the production and release of hydrogen sulfide from waste stabilization ponds, and required design modifications, resulting from increased sulfate or hydrogen sulfide content. A 6-ft deep facultative pond was operated under seven different operating conditions. The experiments were designed to study the relationships between sulfide concentration in the pond and four operating characteristics, namely; detention time, concentration of sulfate ion in the influent, BOD surface load, and sulfate surface load. When detention time and BOD surface loadings were constant, a linear relationship was found to apply between sulfide concentration in the pond and sulfate concentration in the influent. Sulfide concentrations in the pond of about 7 mg per 1 were accompanied by an almost complete disappearance of algae, but the BOD removal rates on a short-term basis were not noticeably affected.

The first major application of computing machines and systems analysis to the design of water resource systems concentrated on the structural components (dams, turbines, diversion works, etc.) and left aside the difficulties inherent in selecting optimal or near-optimal operating policies. Subsequent work, particularly that which dealt with mathematical programming and its several derivatives, offered new insights into the construction of optimal operating schemes. This paper advances one step further in that it combines the selection of components, the specification of optimal operating policies, and the role of streamflow forecasting in a single mathematical entity. No formalism for forecasting is given, but based on a widely accepted model for flow sequences, a technique is developed whereby the analyst can discern whether or not it is useful to include forecasting in the operating policy. The procedure makes extensive use of statistical theory and Monte Carlo analysis.

The paper reports the results of studies which describe the influence of geometry and temperature on the liquid film coefficient, K_L, and the mass transfer coefficient, K_La, for the transfer of oxygen from air bubbles rising in a liquid. It is shown that the liquid film coefficient is related to the total drag force operating at the liquid gas interface. The influence of several surface active agents on KLa and KL are reported. The study indicates that at low concentrations, the principle influence of surface active agents is their effect on the bubble size and rate of rise.

A modification of U-Tube aeration, using low pressure air injection, was studied on a pilot scale. The pilot U-Tube system was made of four inch diameter pipe. Depths of 10 ft, 20 ft, 30 ft, and 40 ft were studied at flow rates up to about 300 gal per min. Air injection rates of 5%, 10%, 15%, and 20% at different depths were studied. The data were subjected to dimensional analysis and equations were derived for predicting prototype results. The effects of air injection depth, U-Tube depth and nominal water velocity on oxygen transfer economy were evaluated. The results show that water containing zero DO can be 100% saturated after one pass through a 40-ft deep U-Tube with 20% air injection. In the process of completely saturating water, the U-Tube oxygen transfer economy (#O₂/HP-hr) is about the same as conventional aeration systems transferring oxygen to water with zero DO.